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Bernath PF, Bhusal M and Liévin J (2024), "Opacities of S-type Stars: The Singlet B 1Π-X 1Σ+, B 1Π-A 1△, and C 1Σ+-X 1Σ+ Band Systems of ZrO", Astrophysical Journal. Vol. 960(1)
Abstract: The ZrO B 1Π-X 1Σ+, B 1Π-A 1Δ, and C 1Σ+-X 1Σ+ band systems are important opacity sources in the near-infrared and optical spectra of S-type stars. A total of 21 rovibronic bands with v″ ≤ 7 and v ′ ≤ 5 were observed and fit for the B 1Π-X 1Σ+ transition, five bands for the 90ZrO B 1Π-A 1Δ transition and one band for the 90ZrO C 1Σ+-X 1Σ+ transition. All band systems were analyzed using high-temperature, high-resolution emission spectra collected at the National Solar Observatory (Kitt Peak). A modern spectroscopic analysis was performed using the PGOPHER program to provide updated spectroscopic constants. In general, we improve the accuracy of the line positions reported in the literature and slightly extend the vibrational analysis. Equilibrium molecular constants were then derived and combined with new ab initio calculations of transition dipole moment functions to produce line lists with line strengths. © 2023. The Author(s). Published by the American Astronomical Society.
BibTeX:
@article{Bernath2024,
  author = {Bernath, Peter F. and Bhusal, Manish and Liévin, Jacques},
  title = {Opacities of S-type Stars: The Singlet B 1Π-X 1Σ+, B 1Π-A 1△, and C 1Σ+-X 1Σ+ Band Systems of ZrO},
  journal = {Astrophysical Journal},
  year = {2024},
  volume = {960},
  number = {1},
  note = {All Open Access, Gold Open Access},
  doi = {10.3847/1538-4357/ad0386}
}
Kuttippurath J, Patel V, Kashyap R, Singh A and Clerbaux C (2024), "Anomalous increase in global atmospheric ammonia during COVID-19 lockdown: Need policies to curb agricultural emissions", Journal of Cleaner Production. Vol. 434
Abstract: The restrictions imposed on human activities during the COVID-19 lockdown (LD) period provided a new scenario to identify potential sources of atmospheric pollution. There are several studies that deal with changes in air quality around the world during LD, but very few on atmospheric ammonia (NH3). Therefore, we examine the changes in global NH3 during LD (April–May 2020) in comparison to the pre-lockdown (PreLD, April–May 2017–2019) and post-lockdown (PostLD, April–May 2021) periods, and assess the factors responsible for these changes. We observe an increase in NH3 during LD across the latitudes, with very high values in the western Europe, Eastern China (EC), the Indian subcontinent and the eastern United States of America (USA). However, a decline in NH3 is observed in some regions of South America (SA) and North America (NA). Similar changes in NH3 during LD are also observed in smaller spatial scales, as found in 3000 cities across the globe. The reduction of sulphur dioxide (SO2), nitrogen dioxide (NO2), nitric acid (HNO3), humidity and cloud cover as a result of restrictions on human activities, particularly in the western Europe and the USA, may have impeded the conversion of NH3 to particulates, which led to a higher NH3 there. Nevertheless, agricultural activities and livestock are the most prominent sources of atmospheric NH3, and were not under restriction during LD, show an enhancement in terms of the use of nitrogen fertilizer, crop production and area harvested, which also cause a rise in NH3 in these regions. Therefore, it is evident that the changes in meteorology and atmospheric composition, together with increased agricultural activities, led to the global increase in atmospheric NH3 during LD. That is, most pollutants show a decline during LD, but NH3 exhibits a rise due to its sources such as agricultural activities. Henceforth, environmental regulations, policies and advanced technologies are required in the agricultural sector, such as fertilizer deep placement using urea briquettes and restricted application of nitrogen fertilizers, to curb NH3 emissions. © 2023 Elsevier Ltd
BibTeX:
@article{Kuttippurath2024,
  author = {Kuttippurath, J. and Patel, V.K. and Kashyap, R. and Singh, A. and Clerbaux, C.},
  title = {Anomalous increase in global atmospheric ammonia during COVID-19 lockdown: Need policies to curb agricultural emissions},
  journal = {Journal of Cleaner Production},
  year = {2024},
  volume = {434},
  doi = {10.1016/j.jclepro.2023.140424}
}
TchanaBetnga W, Hindle F, Manceron L, VanderAuwera J, Cuisset A, Mouret G, Bocquet R, Perrin A, Roy P and Kwabia Tchana F (2024), "A new instrumentation for simultaneous terahertz and mid-infrared spectroscopy in corrosive gaseous mixtures", Review of Scientific Instruments. Vol. 95(1)
Abstract: The correct interpretation of infrared (IR) observations of planetary atmospheres requires an accurate knowledge of temperature and partial and global pressures. Precise laboratory measurements of absorption intensities and line profiles, in the 200-350 K temperature range, are, therefore, critical. However, for gases only existing in complex chemical equilibria, such as nitrous or hypobromous acids, it is not possible to rely on absolute pressure measurements to measure absolute integrated optical absorption cross sections or IR line intensities. To overcome this difficulty, a novel dual-beam terahertz (THz)/mid-IR experimental setup has been developed, relying on the simultaneous use of two instruments. The setup involves a newly constructed temperature-controlled (200-350 K) cross-shaped absorption cell made of inert materials. The cell is traversed by the mid-IR beam from a high-resolution Fourier transform spectrometer using along a White-cell optical configuration providing absorption path lengths from 2.8 to 42 m and by a THz radiation beam (82.5 GHz to 1.1 THz), probing simultaneously the same gaseous sample. The THz channel records pure rotational lines of molecules for which the dipole moment was previously measured with high precision using Stark spectroscopy. This allows for a determination of the partial pressure in the gaseous mixture and enables absolute line intensities to be retrieved for the mid-IR range. This new instrument opens a new possibility for the retrieval of spectroscopic parameters for unstable molecules of atmospheric interest. The design and performance of the equipment are presented and illustrated by an example of simultaneous THz and mid-IR measurement on nitrous acid (HONO) equilibrium. © 2024 Author(s).
BibTeX:
@article{TchanaBetnga2024,
  author = {TchanaBetnga, W. and Hindle, F. and Manceron, L. and VanderAuwera, J. and Cuisset, A. and Mouret, G. and Bocquet, R. and Perrin, A. and Roy, P. and Kwabia Tchana, F.},
  title = {A new instrumentation for simultaneous terahertz and mid-infrared spectroscopy in corrosive gaseous mixtures},
  journal = {Review of Scientific Instruments},
  year = {2024},
  volume = {95},
  number = {1},
  note = {All Open Access, Bronze Open Access},
  doi = {10.1063/5.0178449}
}
Abeed R, Viatte C, Porter WC, Evangeliou N, Clerbaux C, Clarisse L, VanDamme M, Coheur P-F and Safieddine S (2023), "A roadmap to estimating agricultural ammonia volatilization over Europe using satellite observations and simulation data", Atmospheric Chemistry and Physics. Vol. 23(19), pp. 12505 – 12523.
Abstract: Ammonia (NH3) is one of the most important gases emitted from agricultural practices. It affects air quality and the overall climate and is in turn influenced by long-term climate trends as well as by short-term fluctuations in local and regional meteorology. Previous studies have established the capability of the Infrared Atmospheric Sounding Interferometer (IASI) series of instruments, aboard the Metop satellites, to measure ammonia from space since 2007. In this study, we explore the interactions between atmospheric ammonia, land and meteorological variability, and long-term climate trends in Europe. We investigate the emission potential (δsoil) of ammonia from the soil, which describes the soil-atmosphere ammonia exchange. δsoil is generally calculated in-field or in laboratory experiments; here, and for the first time, we investigate a method which assesses it remotely using satellite data, reanalysis data products, and model simulations. We focus on ammonia emission potential in March 2011, which marks the start of growing season in Europe. Our results show that δsoil ranges from 2 × 103 to 9.5 × 104 (dimensionless) in fertilized cropland, such as in the North European Plain, and is of the order of 10-102 in a non-fertilized soil (e.g., forest and grassland). These results agree with in-field measurements from the literature, suggesting that our method can be used in other seasons and regions in the world. However, some improvements are needed in the determination of mass transfer coefficient k (ms-1), which is a crucial parameter to derive δsoil. Using a climate model, we estimate the expected increase in ammonia columns by the end of the century based on the increase in skin temperature (Tskin), under two different climate scenarios. Ammonia columns are projected to increase by up to 50 %, particularly in eastern Europe, under the SSP2-4.5 scenario and might even double (increase of 100 %) under the SSP5-8.5 scenario. The increase in skin temperature is responsible for a formation of new hotspots of ammonia in Belarus, Ukraine, Hungary, Moldova, parts of Romania, and Switzerland. © 2023 Rimal Abeed et al.
BibTeX:
@article{Abeed2023,
  author = {Abeed, Rimal and Viatte, Camille and Porter, William C. and Evangeliou, Nikolaos and Clerbaux, Cathy and Clarisse, Lieven and VanDamme, Martin and Coheur, Pierre-François and Safieddine, Sarah},
  title = {A roadmap to estimating agricultural ammonia volatilization over Europe using satellite observations and simulation data},
  journal = {Atmospheric Chemistry and Physics},
  year = {2023},
  volume = {23},
  number = {19},
  pages = {12505 – 12523},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-23-12505-2023}
}
Aerts A, Jolly SW, Kockaert P, Gorza S-P, Auwera JV and Vaeck N (2023), "Modulated super-Gaussian laser pulse to populate a dark rovibrational state of acetylene", Journal of Chemical Physics. Vol. 159(8)
Abstract: A pulse-shaping technique in the mid-infrared spectral range based on pulses with a super-Gaussian temporal profile is considered for laser control. We show a realistic and efficient path to the population of a dark rovibrational state in acetylene (C2H2). The laser-induced dynamics in C2H2 are simulated using fully experimental structural parameters. Indeed, the rotation-vibration energy structure, including anharmonicities, is defined by the global spectroscopic Hamiltonian for the ground electronic state of C2H2 built from the extensive high-resolution spectroscopy studies on the molecule, transition dipole moments from intensities, and the effects of the (inelastic) collisions that are parameterized from line broadenings using the relaxation matrix [A. Aerts, J. VanderAuwera, and N. Vaeck, J. Chem. Phys. 154, 144308 (2021)]. The approach, based on an effective Hamiltonian, outperforms today’s ab initio computations both in terms of accuracy and computational cost for this class of molecules. With such accuracy, the Hamiltonian permits studying the inner mechanism of theoretical pulse shaping [A. Aerts et al., J. Chem. Phys. 156, 084302 (2022)] for laser quantum control. Here, the generated control pulse presents a number of interferences that take advantage of the control mechanism to populate the dark state. An experimental setup is proposed for in-laboratory investigation. © 2023 Author(s).
BibTeX:
@article{Aerts2023,
  author = {Aerts, Antoine and Jolly, Spencer W. and Kockaert, Pascal and Gorza, Simon-Pierre and Auwera, Jean Vander and Vaeck, Nathalie},
  title = {Modulated super-Gaussian laser pulse to populate a dark rovibrational state of acetylene},
  journal = {Journal of Chemical Physics},
  year = {2023},
  volume = {159},
  number = {8},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/5.0160526}
}
Beaudor M, Vuichard N, Lathiere J, Evangeliou N, VanDamme M, Clarisse L and Hauglustaine D (2023), "Global agricultural ammonia emissions simulated with the ORCHIDEE land surface model", Geoscientific Model Development. Vol. 16(3), pp. 1053 – 1081.
Abstract: Ammonia (NH3) is an important atmospheric constituent. It plays a role in air quality and climate through the formation of ammonium sulfate and ammonium nitrate particles. It has also an impact on ecosystems through deposition processes. About 85g% of NH3 global anthropogenic emissions are related to food and feed production and, in particular, to the use of mineral fertilizers and manure management. Most global chemistry transport models (CTMs) rely on bottom-up emission inventories, which are subject to significant uncertainties. In this study, we estimate emissions from livestock by developing a new module to calculate ammonia emissions from the whole agricultural sector (from housing and storage to grazing and fertilizer application) within the ORCHIDEE (Organising Carbon and Hydrology In Dynamic Ecosystems) global land surface model. We detail the approach used for quantifying livestock feed management, manure application, and indoor and soil emissions and subsequently evaluate the model performance. Our results reflect China, India, Africa, Latin America, the USA, and Europe as the main contributors to global NH3 emissions, accounting for 80g% of the total budget. The global calculated emissions reach 44gTgNyr-1 over the 2005-2015 period, which is within the range estimated by previous work. Key parameters (e.g., the pH of the manure, timing of N application, and atmospheric NH3 surface concentration) that drive the soil emissions have also been tested in order to assess the sensitivity of our model. Manure pH is the parameter to which modeled emissions are the most sensitive, with a 10g% change in emissions per percent change in pH. Even though we found an underestimation in our emissions over Europe (-26g%) and an overestimation in the USA (+56g%) compared with previous work, other hot spot regions are consistent. The calculated emission seasonality is in very good agreement with satellite-based emissions. These encouraging results prove the potential of coupling ORCHIDEE land-based emissions to CTMs, which are currently forced by bottom-up anthropogenic-centered inventories such as the CEDS (Community Emissions Data System). © Copyright:
BibTeX:
@article{Beaudor2023,
  author = {Beaudor, Maureen and Vuichard, Nicolas and Lathiere, Juliette and Evangeliou, Nikolaos and VanDamme, Martin and Clarisse, Lieven and Hauglustaine, Didier},
  title = {Global agricultural ammonia emissions simulated with the ORCHIDEE land surface model},
  journal = {Geoscientific Model Development},
  year = {2023},
  volume = {16},
  number = {3},
  pages = {1053 – 1081},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/gmd-16-1053-2023}
}
Bernath P, Dodangodage R and Liévin J (2023), "S-type Stars: Line List for the A2Π-X2Σ+ Band System of LaO", Astrophysical Journal. Vol. 953(2)
Abstract: LaO bands are found in the spectra of cool S-type stars. The bands of the A2Π-X2Σ+ transition with v ′ ≤ 3 and v″ ≤ 4 are rotationally analyzed, providing spectroscopic constants for the A2Π state. Line strengths are calculated using an ab initio transition dipole moment function, and radiative lifetimes for the A2Π state have also been computed. A line list for the A2Π-X2Σ+ transition of LaO is provided and can be used to determine LaO stellar abundances. © 2023. The Author(s). Published by the American Astronomical Society.
BibTeX:
@article{Bernath2023,
  author = {Bernath, P.F. and Dodangodage, R. and Liévin, J.},
  title = {S-type Stars: Line List for the A2Π-X2Σ+ Band System of LaO},
  journal = {Astrophysical Journal},
  year = {2023},
  volume = {953},
  number = {2},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3847/1538-4357/ace68a}
}
Blake JS, Fletcher L, Orton G, Antuñano A, Roman M, Kasaba Y, Fujiyoshi T, Melin H, Bardet D, Sinclair J and Es-Sayeh M (2023), "Saturn's seasonal variability from four decades of ground-based mid-infrared observations", Icarus. Vol. 392
Abstract: A multi-decade record of ground-based mid-infrared (7–25μm) images of Saturn is used to explore seasonal and non-seasonal variability in thermal emission over more than a Saturnian year (1984–2022). Thermal emission measured by 3-m and 8-m-class observatories (notably NASA's Infrared Telescope Facility, Subaru, and ESO's Very Large Telescope) compares favourably with synthetic images based on both Cassini-derived temperature records and the predictions of radiative climate models. We find that 8-m class facilities are capable of resolving thermal contrasts on the scale of Saturn's belts, zones, polar hexagon, and polar cyclones, superimposed onto large-scale seasonal asymmetries. Seasonal changes in brightness temperatures of ∼30 K in the stratosphere and ∼10 K in the upper troposphere are observed, as the northern and southern polar stratospheric vortices (NPSV and SPSV) form in spring and dissipate in autumn. The timings of the first appearance of the warm polar vortices is successfully reproduced by radiative climate models, confirming them to be radiative phenomena, albeit entrained within sharp boundaries influenced by dynamics. Axisymmetric thermal bands (4–5 per hemisphere) display temperature gradients that are strongly correlated with Saturn's zonal winds, indicating winds that decay in strength with altitude from the cloud-tops to the ∼1-mbar level, and implying meridional circulation cells in Saturn's upper troposphere and stratosphere forming the system of cool zones and warm belts. Saturn's thermal structure is largely repeatable from year to year (via comparison of infrared images in 1989 and 2018), with the exception of low-latitudes. Here we find evidence of inter-annual variations because the equatorial banding at 7.9μm is inconsistent with a ∼15-year period for Saturn's equatorial stratospheric oscillation, i.e., it is not strictly semi-annual. Either the oscillation has a longer period closer to ∼20 years, or its progression is naturally variable and interrupted by tropospheric meteorology (e.g., storms). Finally, observations between 2017–2022 extend the legacy of the Cassini mission, revealing the continued warming of the NPSV during northern summer in line with predictions of radiative climate models. © 2022 The Authors
BibTeX:
@article{Blake2023,
  author = {Blake, James S.D. and Fletcher, L.N. and Orton, G.S. and Antuñano, A. and Roman, M.T. and Kasaba, Y. and Fujiyoshi, T. and Melin, H. and Bardet, D. and Sinclair, J.A. and Es-Sayeh, M.},
  title = {Saturn's seasonal variability from four decades of ground-based mid-infrared observations},
  journal = {Icarus},
  year = {2023},
  volume = {392},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.icarus.2022.115347}
}
Bouillon M, Safieddine S and Clerbaux C (2023), "Sudden Stratospheric Warmings in the Northern Hemisphere Observed With IASI", Journal of Geophysical Research: Atmospheres. Vol. 128(17)
Abstract: Sudden Stratospheric Warming events (SSW) are extreme phenomena during which stratospheric temperature can increase by tens of degrees in a few days. They are due to the propagation and breaking of the planetary waves, leading to a perturbation of the polar vortex. SSWs also influence polar ozone concentrations and midlatitude weather. The Infrared Atmospheric Sounding Interferometers (IASI) monitor atmospheric composition and temperature globally since 2007, and they are ideal to observe the changes of temperature and ozone during SSWs. Since the launch of the first IASI, there have been several SSWs in the Northern Hemisphere, including eight major events that are investigated in this study. We find that during major SSWs, the temperature anomaly propagates from 10 hPa to the lower stratosphere and the maximum anomaly at 200 hPa is correlated to the maximum anomaly at 10 hPa. During these events, negative anomalies of temperature in Europe and Russia and positive anomalies in Canada and Greenland are often observed at 750 hPa. The cold air outbreaks that usually follow major SSWs are responsible for anomalies of −15 K. Finally, we look at the evolution of the total ozone column following major events. Major SSWs lead to higher springtime ozone concentrations and the ozone anomaly in March is correlated to the duration of the positive temperature anomaly at 10 hPa. These results show the potential of the IASI mission and its successors, IASI-New Generation, for the study of SSWs and their effects on weather and atmospheric composition. © 2023 The Authors.
BibTeX:
@article{Bouillon2023,
  author = {Bouillon, Marie and Safieddine, Sarah and Clerbaux, Cathy},
  title = {Sudden Stratospheric Warmings in the Northern Hemisphere Observed With IASI},
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2023},
  volume = {128},
  number = {17},
  note = {All Open Access, Hybrid Gold Open Access},
  doi = {10.1029/2023JD038692}
}
Cacciani P, Čermák P, Votava O, VanderAuwera J and Campargue A (2023), "The ammonia absorption spectrum revisited between 5650 and 6350 cm−1", Molecular Physics.
Abstract: The ammonia spectrum is revisited in the important 1.6 µm atmospheric transparency window between 5650 and 6350 cm (Formula presented.)  on the basis of recently recorded high-resolution Fourier transform spectra. These spectra offer an improved frequency sampling and better traceability of the measurement conditions compared to previously studied Kitt Peak spectra (Cacciani et al. J. Quant Spectrosc Radiat Transf 2021; 258:107334. https://doi.org/10.1016/j.jqsrt.2020.107334). Overall, 4812  (Formula presented.) NH (Formula presented.)  lines were measured in the 5650–6350 cm (Formula presented.)  region corresponding to 4866 transitions including 2066 new ones compared with our previous study, included in the HITRAN2020 database. The energy of 1023 upper state levels (including 107 new ones) was derived from 2608 assigned transitions. Independently, ammonia spectra recorded in a supersonic jet expansion using a tunable extended cavity diode laser allow us to check the absolute transition energies in the 5980–6080 cm (Formula presented.)  range. Accurate jet spectra calibration was achieved using CH (Formula presented.) reference line positions known with kHz accuracy. The position agreement with the FTS data is within the (Formula presented.) cm (Formula presented.)  uncertainty of the positions measured in the jet expansion. A recommended line list of 5620 transitions is provided for (Formula presented.) NH (Formula presented.)  in the considered 5650–6350 cm (Formula presented.)  region. © 2023 Informa UK Limited, trading as Taylor & Francis Group.
BibTeX:
@article{Cacciani2023,
  author = {Cacciani, P. and Čermák, P. and Votava, O. and VanderAuwera, J. and Campargue, A.},
  title = {The ammonia absorption spectrum revisited between 5650 and 6350 cm−1},
  journal = {Molecular Physics},
  year = {2023},
  note = {All Open Access, Green Open Access},
  doi = {10.1080/00268976.2023.2256893}
}
CarvajalGallego H, Deprince J, Godefroid M, Goriely S, Palmeri P and Quinet P (2023), "On the importance of using realistic partition functions in kilonova opacity calculations", European Physical Journal D. Vol. 77(5)
Abstract: Abstract: In the present work, we report an investigation on the importance of using realistic partition functions in the opacity calculations of lanthanide ions whether they are moderately or lowly ionized. In order to do this, atomic data for various moderately charged samarium (Sm V–XI) and lowly charged neodymium (Nd II–IV) ions were calculated by the pseudo-relativistic Hartree–Fock method (HFR) and then, used to compute the expansion opacities for conditions characterizing the ejecta of kilonovae observed as a result of neutron star mergers, with a particular attention given to the partition function computations. Graphical abstract: [Figure not available: see fulltext.] © 2023, The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature.
BibTeX:
@article{CarvajalGallego2023,
  author = {CarvajalGallego, Helena and Deprince, Jérôme and Godefroid, Michel and Goriely, Stéphane and Palmeri, Patrick and Quinet, Pascal},
  title = {On the importance of using realistic partition functions in kilonova opacity calculations},
  journal = {European Physical Journal D},
  year = {2023},
  volume = {77},
  number = {5},
  note = {All Open Access, Green Open Access},
  doi = {10.1140/epjd/s10053-023-00638-0}
}
Ceamanos X, Coopman Q, George M, Riedi J, Parrington M and Clerbaux C (2023), "Remote sensing and model analysis of biomass burning smoke transported across the Atlantic during the 2020 Western US wildfire season", Scientific Reports. Vol. 13(1)
Abstract: Biomass burning is the main source of air pollution in several regions worldwide nowadays. This predominance is expected to increase in the upcoming years as a result of the rising number of devastating wildfires due to climate change. Harmful pollutants contained in the smoke emitted by fires can alter downwind air quality both locally and remotely as a consequence of the recurrent transport of biomass burning plumes across thousands of kilometers. Here, we demonstrate how observations of carbon monoxide and aerosol optical depth retrieved from polar orbiting and geostationary meteorological satellites can be used to study the long-range transport and evolution of smoke plumes. This is illustrated through the megafire events that occurred during summer 2020 in the Western United States and the transport of the emitted smoke across the Atlantic Ocean to Europe. Analyses from the Copernicus Atmosphere Monitoring Service, which combine satellite observations with an atmospheric model, are used for comparison across the region of study and along simulated air parcel trajectories. Lidar observation from spaceborne and ground-based instruments are used to verify consistency of passive observations. Results show the potential of joint satellite-model analysis to understand the emission, transport, and processing of smoke across the world. © 2023, Springer Nature Limited.
BibTeX:
@article{Ceamanos2023,
  author = {Ceamanos, Xavier and Coopman, Quentin and George, Maya and Riedi, Jérôme and Parrington, Mark and Clerbaux, Cathy},
  title = {Remote sensing and model analysis of biomass burning smoke transported across the Atlantic during the 2020 Western US wildfire season},
  journal = {Scientific Reports},
  year = {2023},
  volume = {13},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1038/s41598-023-39312-1}
}
Clarisse L, Franco B, VanDamme M, Di Gioacchino T, Hadji-Lazaro J, Whitburn S, Noppen L, Hurtmans D, Clerbaux C and Coheur P (2023), "The IASI NH3 version 4 product: averaging kernels and improved consistency", Atmospheric Measurement Techniques. Vol. 16(21), pp. 5009 – 5028.
Abstract: Satellite measurements play an increasingly important role in the study of atmospheric ammonia (NH3). Here, we present version 4 of the Artificial Neural Network for IASI (ANNI; IASI: Infrared Atmospheric Sounding Interferometer) retrieval of NH3. The main change is the introduction of total column averaging kernels (AVKs), which can be used to undo the effect of the vertical profile shape assumption of the retrieval. While the main equations can be matched term for term with analogous ones used in UV/Vis retrievals for other minor absorbers, we derive the formalism from the ground up, as its applicability to thermal infrared measurements is non-trivial. A large number of other smaller changes were introduced in ANNI v4, most of which improve the consistency of the measurements across time and across the series of IASI instruments. This includes a more robust way of calculating the hyperspectral range index (HRI), explicitly accounting for long-term changes in CO2 in the HRI calculation and the use of a reprocessed cloud product that was specifically developed for climate applications. The NH3 distributions derived with ANNI v4 are very similar to the ones derived with v3, although values are about 10 %-20 % larger due to the improved setup of the HRI. We exclude further large biases of the same nature by showing the consistency between ANNI v4 derived NH3 columns with columns obtained with an optimal estimation approach. Finally, with v4, we revised the uncertainty budget and now report systematic uncertainty estimates alongside random uncertainties, allowing realistic mean uncertainties to be estimated. Copyright: © 2023 Lieven Clarisse et al.
BibTeX:
@article{Clarisse2023,
  author = {Clarisse, Lieven and Franco, Bruno and VanDamme, Martin and Di Gioacchino, Tommaso and Hadji-Lazaro, Juliette and Whitburn, Simon and Noppen, Lara and Hurtmans, Daniel and Clerbaux, Cathy and Coheur, Pierre},
  title = {The IASI NH3 version 4 product: averaging kernels and improved consistency},
  journal = {Atmospheric Measurement Techniques},
  year = {2023},
  volume = {16},
  number = {21},
  pages = {5009 – 5028},
  doi = {10.5194/amt-16-5009-2023}
}
Dang R, Jacob DJ, Zhai S, Coheur P, Clarisse L, VanDamme M, Pendergrass DC, Choi J-s, Park J-s, Liu Z and Liao H (2023), "Diagnosing the Sensitivity of Particulate Nitrate to Precursor Emissions Using Satellite Observations of Ammonia and Nitrogen Dioxide", Geophysical Research Letters. Vol. 50(24)
Abstract: Particulate nitrate is a major component of fine particulate matter (PM2.5). Its formation may be varyingly sensitive to emissions of ammonia (NH3), nitrogen oxides (NOx ≡ NO + NO2), and volatile organic compounds (VOCs), depending on local conditions. Diagnosing these sensitivities is critical for successful air quality management. Here, we show that satellite measurements of tropospheric NH3 and NO2 columns can be used as a quick indicator of the dominant sensitivity regime through the NH3/NO2 column ratio together with the NO2 column. We demonstrate the effectiveness of this indicator with the GEOS-Chem chemical transport model and define thresholds to separate the different sensitivity regimes. Applying the method to wintertime IASI and OMI observations in East Asia reveals that surface nitrate is dominantly VOC-sensitive in the southern North China Plain (NCP), NOx-sensitive in most of the East China Plain, and NH3-sensitive in the northern NCP, southern China, and Korea. © 2023. The Authors.
BibTeX:
@article{Dang2023,
  author = {Dang, Ruijun and Jacob, Daniel J. and Zhai, Shixian and Coheur, Pierre and Clarisse, Lieven and VanDamme, Martin and Pendergrass, Drew C. and Choi, Jin-soo and Park, Jin-soo and Liu, Zirui and Liao, Hong},
  title = {Diagnosing the Sensitivity of Particulate Nitrate to Precursor Emissions Using Satellite Observations of Ammonia and Nitrogen Dioxide},
  journal = {Geophysical Research Letters},
  year = {2023},
  volume = {50},
  number = {24},
  note = {All Open Access, Hybrid Gold Open Access},
  doi = {10.1029/2023GL105761}
}
Deguine A, Clarisse L, Herbin H and Petitprez D (2023), "Measuring Volcanic Ash with High-Spectral Resolution Infrared Sounders: Role of Refractive Indices", IEEE Geoscience and Remote Sensing Letters. Vol. 20
Abstract: Airborne volcanic ash can be observed and quantified from hyperspectral infrared (IR) sounders. The retrieval process of physical quantities, such as particle radius and mass, depends critically on the assumed spectrally dependent complex refractive indices (CRIs) that are used. Traditionally, the Pollack et al. (1973) dataset was used almost exclusively. These indices are, however, based on measurements of rock slabs, and in recent years, two datasets have become available from laboratory measurements of ash in suspension, the Reed et al. (2018) and Deguine et al. (2020) datasets. Here, we compare the three datasets and quantify the extent to which each of them can be used to simulate satellite observed spectra of real volcanic ash plumes. We find that whereas the Pollack et al. indices perform worst throughout, the performance of the other two is comparable for andesitic and basaltic ash plumes. However, all three datasets have difficulty in reproducing the extinction minimum around 1250 cm-1. The Reed et al. indices in addition yield inconsistent results in the 800-850 cm-1 range. The Deguine et al. dataset is the only one, which can be used to reproduce the very large spectral signatures often observed with rhyolitic ash across the entire thermal IR window 750-1250 cm-1. In terms of retrieved quantities, the largest differences are seen for the radius, with the Deguine et al. dataset resulting in the smallest retrieved particle sizes. © 2004-2012 IEEE.
BibTeX:
@article{Deguine2023,
  author = {Deguine, Alexandre and Clarisse, Lieven and Herbin, Herve and Petitprez, Denis},
  title = {Measuring Volcanic Ash with High-Spectral Resolution Infrared Sounders: Role of Refractive Indices},
  journal = {IEEE Geoscience and Remote Sensing Letters},
  year = {2023},
  volume = {20},
  doi = {10.1109/LGRS.2023.3261202}
}
Deguine A, Petitprez D, Clarisse L, Deschutter L, Fontijn K and Herbin H (2023), "Retrieval of refractive indices of ten volcanic ash samples in the infrared, visible and ultraviolet spectral region", Journal of Aerosol Science. Vol. 167
Abstract: Volcanic eruptions can emit large amounts of ash into the atmosphere, which can have significant impacts on infrastructure, human health, agriculture and air traffic. Remote sensing instruments can efficiently detect airborne ash plumes, and the measured spectra can be exploited to obtain information on the physical characteristics of ash (grain size distribution, concentration, optical depth). The key parameter on which all such satellite retrievals depend is the complex refractive index (CRI) which remains one of the largest sources of uncertainty in the retrieval process. Here we present a complementary dataset of refractive indices of volcanic ash to that published by Deguine et al. (2020), to cover a part of the major explosive eruptions occurred during the past 50 years. These CRIs were obtained using an innovative experimental methodology which consists in measuring simultaneously the extinction spectra in the IR and UV/visible domain and the size distribution of ash in suspension in a nitrogen flow. These experimental data are the main input to the retrieval process of CRI. The numerical routine uses Mie theory coupled with Kramers–Kronig relationship to retrieve the imaginary and the real part of the complex refractive index. This methodology has been successfully applied on samples collected from various eruptions and deposits in Indonesia (Kelud), Chile (Chaitén), Italy (Stromboli), Russia (Karymsky), Tanzania (Rungwe, Mount Meru), Ethiopia (Corbetti), Philippines (Taal, Pinatubo) and USA (Mount St. Helens). Significant variations of the real and imaginary part of the CRI are observed according to the chemical composition of the samples. Moreover, the sensitivity of the CRI to chemical composition and mineralogical structure (amorphous/crystalline fraction) has been investigated and shows a strong dependence of the CRI on these parameters. © 2022 Elsevier Ltd
BibTeX:
@article{Deguine2023a,
  author = {Deguine, Alexandre and Petitprez, Denis and Clarisse, Lieven and Deschutter, Lise and Fontijn, Karen and Herbin, Hervé},
  title = {Retrieval of refractive indices of ten volcanic ash samples in the infrared, visible and ultraviolet spectral region},
  journal = {Journal of Aerosol Science},
  year = {2023},
  volume = {167},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.jaerosci.2022.106100}
}
DeLongueville H, Clarisse L, Whitburn S, Clerbaux C, Lecomte G and Coheur P (2023), "Atmospheric trends of long-lived halogenated gases derived from 15 years of IASI measurements", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 311
Abstract: Atmospheric emissions of chlorofluorocarbons (CFCs), their hydrogenated derivatives (HCFCs, HFCs) and other long-lived halogen-containing substances perturb the chemical and radiative equilibrium of our atmosphere. A global network of ground-based stations (AGAGE) monitors the concentrations of most of these species. Supplementing these, upper tropospheric and stratospheric concentrations are available from satellite measurements of the ACE-FTS solar occultation sounder. Measurements derived from nadir viewing infrared sounders can potentially complement both observational datasets, offering extensive spatial coverage and temporal sampling. With a preferential sensitivity to the middle troposphere, they also cover the vertical altitude range that is not covered by other means. However, fluctuations in surface temperature and the concentration of interfering atmospheric constituents render the retrieval of halogenated species particularly challenging. Relying on previous work on spectral whitening, we present an unconstrained generalized least squares estimation retrieval methodology, which largely allows to overcome the problem of interference. We demonstrate that it can be used to retrieve monthly anomalies of all halogenated species previously observed in spectra from the Infrared Atmospheric Sounding Interferometer (IASI/Metop). Focussing on northern mid-latitudes, we derive the monthly concentrations of CFC-11, CFC-12, HCFC-22, HCFC-142b, HFC-134a, CF4, SF6 and CCl4 between 2008 and 2022. Trends are compared to the observations from AGAGE and ACE-FTS. A good match is obtained with both, with especially remarkable agreement in the linear trends for CF4, SF6 and HFC-134a, and in the non-linear trends of CFC-11 and HCFC-22. Large discrepancies and unexplained variations are seen in the time series of HCFC-142b, CFC-12 and CCl4, necessitating further optimization of the retrieval technique. The results demonstrate the potential of IASI and follow-up missions for establishing a unique long-term time series of the most important long-lived halogenated species. © 2023 The Author(s)
BibTeX:
@article{DeLongueville2023,
  author = {DeLongueville, Hélène and Clarisse, Lieven and Whitburn, Simon and Clerbaux, Cathy and Lecomte, Gilles and Coheur, Pierre},
  title = {Atmospheric trends of long-lived halogenated gases derived from 15 years of IASI measurements},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2023},
  volume = {311},
  note = {All Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.jqsrt.2023.108755}
}
Demaison J, Liévin J and Vogt N (2023), "Accurate equilibrium structures of some challenging molecules: FNO, ClNO, HONO, FNO2, and N2O", Journal of Molecular Spectroscopy. Vol. 394
Abstract: It is sometimes difficult to determine the structure of some molecules because the optimization using standard ab initio methods (coupled-cluster with single, double, and perturbative triples [CCSD(T)] level) does not give the correct result and the experimental and semiexperimental methods are not accurate because the system of normal equations of the least-squares method is ill-conditioned. In such a case, it may be still possible to derive an accurate equilibrium structure in the following way: the experimental rotational constants are compared to those obtained at the CCSD(T) level, the latter being corrected to take into account the rovibrational correction (and, if necessary, the electronic correction). Extrapolating (or interpolating) the rotational constants calculated with different basis sets (e.g. cc-pwCVTZ and cc-pwCVQZ) towards the experimental values as a function of the bond lengths and angles permits to obtain an accurate equilibrium structure. This method is first tested on two molecules for which the multireference effects are important: O3 and HOON. It is then, applied to molecules with a weak N–X bond (HONO, FNO, ClNO, FNO2, and N2O) for which the single reference CCSD(T) method gives bonds that are too short. The results are compared to the experimental and semiexperimental equilibrium structures. As a further check, the structure of ClNO is calculated at the CCSDTQ level and the structures of FNO and ClNO are calculated at the MRCI-F12 level. From a comparison of the different results, it appears that the accuracy of the proposed method is better than 0.002 Å for the bond lengths and 0.3° for the angles. © 2023 Elsevier Inc.
BibTeX:
@article{Demaison2023,
  author = {Demaison, Jean and Liévin, Jacques and Vogt, Natalja},
  title = {Accurate equilibrium structures of some challenging molecules: FNO, ClNO, HONO, FNO2, and N2O},
  journal = {Journal of Molecular Spectroscopy},
  year = {2023},
  volume = {394},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jms.2023.111788}
}
Deprince J, Carvajal Gallego H, Godefroid M, Goriely S, Palmeri P and Quinet P (2023), "On the sensitivity of uranium opacity with respect to the atomic properties in the context of kilonova emission modeling", European Physical Journal D. Vol. 77(6)
Abstract: Abstract: In this study, the sensitivity of the opacities with respect to the atomic parameters is investigated in the case of weakly charged uranium ions. In order to do this, atomic data for U II and U III were calculated with the pseudo-relativistic Hartree–Fock method (HFR) and then, used to determine the expansion opacities for conditions characterizing the ejecta of kilonovae that follow neutron star mergers. In particular, we studied the sensitivity of the opacity with respect to the use of atomic data obtained considering several effects as the ionic core polarization and an adjustment procedure. Graphical abstract: [Figure not available: see fulltext.]. © 2023, The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature.
BibTeX:
@article{Deprince2023,
  author = {Deprince, Jérôme and Carvajal Gallego, Helena and Godefroid, Michel and Goriely, Stéphane and Palmeri, Patrick and Quinet, Pascal},
  title = {On the sensitivity of uranium opacity with respect to the atomic properties in the context of kilonova emission modeling},
  journal = {European Physical Journal D},
  year = {2023},
  volume = {77},
  number = {6},
  note = {All Open Access, Green Open Access},
  doi = {10.1140/epjd/s10053-023-00671-z}
}
Es-Sayeh M, Rodriguez S, Coutelier M, Rannou P, Bézard B, Maltagliati L, Cornet T, Grieger B, Karkoschka E, Le Mouélic S, Le Gall A, Neish C, MacKenzie S, Solomonidou A, Sotin C and Coustenis A (2023), "Updated Radiative Transfer Model for Titan in the Near-infrared Wavelength Range: Validation against Huygens Atmospheric and Surface Measurements and Application to the Cassini/VIMS Observations of the Dragonfly Landing Area", Planetary Science Journal. Vol. 4(3)
Abstract: We present an analysis of Titan data acquired by the Cassini Visual and Infrared Mapping Spectrometer (VIMS) at the landing site of the Dragonfly mission, using a new version of our radiative transfer model for Titan, with significant updates for the spectroscopic parameters of atmospheric gases and photochemical aerosols. Our updated radiative transfer model is validated against the in situ spectroscopic measurements of the Huygens probe during its descent and once landed. We confirm that aerosols with a fractal dimension of 2.3-2.4 provide the best fit to the observations. We apply our radiative transfer model to four VIMS data cubes over the Selk crater region including the Dragonfly landing and exploration areas, further validating our model by producing consistent aerosol population and surface albedo maps. These infrared albedo maps, further corrected from the photometry, enable us to study the Selk crater region in terms of surface composition, landscape formation, and evolution. Our results suggest that the Selk crater is in an intermediate state of degradation and that the mountainous terrains of the area (including the crater rim and ejecta) are likely to be dominated by fine grains of tholin-like sediment. This organic sediment would be transported to the lowlands (crater floor and surrounding plains), possibly with water ice particles, by rivers, and further deposited and processed to form the sand particles that feed the neighboring dune fields. These results provide information for the operational and scientific preparation of the Dragonfly mission, paving the way for future exploration of Titan’s surface composition and geology. © 2023. The Author(s). Published by the American Astronomical Society.
BibTeX:
@article{EsSayeh2023,
  author = {Es-Sayeh, M. and Rodriguez, S. and Coutelier, M. and Rannou, P. and Bézard, B. and Maltagliati, L. and Cornet, T. and Grieger, B. and Karkoschka, E. and Le Mouélic, S. and Le Gall, A. and Neish, C. and MacKenzie, S. and Solomonidou, A. and Sotin, C. and Coustenis, A.},
  title = {Updated Radiative Transfer Model for Titan in the Near-infrared Wavelength Range: Validation against Huygens Atmospheric and Surface Measurements and Application to the Cassini/VIMS Observations of the Dragonfly Landing Area},
  journal = {Planetary Science Journal},
  year = {2023},
  volume = {4},
  number = {3},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3847/PSJ/acbd37}
}
Flörs A, Silva R, Deprince J, CarvajalGallego H, Leck G, Shingles L, Martínez-Pinedo G, Sampaio J, Amaro P, Marques J, Goriely S, Quinet P, Palmeri P and Godefroid M (2023), "Opacities of singly and doubly ionized neodymium and uranium for kilonova emission modeling", Monthly Notices of the Royal Astronomical Society. Vol. 524(2), pp. 3083 – 3101.
Abstract: Even though the electromagnetic counterpart AT2017gfo to the binary neutron star merger GW170817 is powered by the radioactive decay of r-process nuclei, only few tentative identifications of light r-process elements have been made so far. One of the major limitations for the identification of heavy nuclei is incomplete or missing atomic data. While substantial progress has been made on lanthanide atomic data over the last few years, for actinides there has been less emphasis, with the first complete set of opacity data only recently published. We perform atomic structure calculations of neodymium (Z = 60) as well as the corresponding actinide uranium (Z = 92). Using two different codes [ FLEXIBLE ATOMIC CODE (FAC) and HARTREE-FOCK- RELATIVISTIC (HFR)] for the calculation of the atomic data, we investigate the accuracy of the calculated data (energy levels and electric dipole transitions) and their effect on kilonova opacities. For the FAC calculations, we optimize the local central potential and the number of included configurations and use a dedicated calibration technique to improve the agreement between theoretical and available experimental atomic energy levels (AELs). For ions with vast amounts of experimental data available, the presented opacities agree quite well with previous estimations. On the other hand, the optimization and calibration method cannot be used for ions with only few available AELs. For these cases, where no experimental nor benchmarked calculations are available, a large spread in the opacities estimated from the atomic data obtained with the various atomic structure codes is observed. We find that the opacity of uranium is almost double the neodymium opacity. © 2023 The Author(s).
BibTeX:
@article{Floers2023,
  author = {Flörs, A. and Silva, R.F. and Deprince, J. and CarvajalGallego, H. and Leck, G. and Shingles, L.J. and Martínez-Pinedo, G. and Sampaio, J.M. and Amaro, P. and Marques, J.P. and Goriely, S. and Quinet, P. and Palmeri, P. and Godefroid, M.},
  title = {Opacities of singly and doubly ionized neodymium and uranium for kilonova emission modeling},
  journal = {Monthly Notices of the Royal Astronomical Society},
  year = {2023},
  volume = {524},
  number = {2},
  pages = {3083 – 3101},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1093/mnras/stad2053}
}
FroeseFischer C and Godefroid M (2023), "Atomic Structure: Variational Wave Functions and Properties", Springer Handbooks. , pp. 309 – 330.
Abstract: This chapter describes variational methods for the determination of wave functions either in nonrelativistic (LS), quasi relativistic Breit–Pauli (LSJ), or Dirac (jj) theory. The emphasis is on Hartree–Fock and multiconfiguration Hartree–Fock theory with reference to similar Dirac theory. Although the underlying mathematics of the latter is technically different because of the properties of Dirac spinors, we draw parallels between the nonrelativistic and relativistic formulations that lay the foundation of, respectively, the Atomic Structure Package (ATSP) 1 ; 2 and the General Relativistic Atomic Structure Package (GRASP) 3 ; 4. Some results from the application of these multiconfiguration methods are presented for a number of atomic properties. Although framed entirely in terms of nonrelativistic calculations, the present chapter reveals a pattern that can be, and actually is, explored in the review article of variational theory 5 as in the following Chap. 23 on Relativistic Atomic Structure. © 2023, Springer Nature Switzerland AG.
BibTeX:
@article{FroeseFischer2023,
  author = {FroeseFischer, Charlotte and Godefroid, Michel},
  title = {Atomic Structure: Variational Wave Functions and Properties},
  journal = {Springer Handbooks},
  year = {2023},
  pages = {309 – 330},
  doi = {10.1007/978-3-030-73893-8_22}
}
Gans B, Liévin J, Halvick P, Chen N, Boyé-Péronne S, Hartweg S, Garcia G and Loison J-C (2023), "Single-photon ionization of SiC in the gas phase: experimental and ab initio characterization of SiC+", Physical Chemistry Chemical Physics. Vol. 25(35), pp. 23568 – 23578.
Abstract: We report the first experimental observation of single-photon ionization transitions of the SiC radical between 8.0 and 11.0 eV performed on the DESIRS beamline at the SOLEIL synchrotron facility. The SiC radical, very difficult to synthesize in the gas phase, was produced through chemical reactions between CHx (x = 0-3) and SiHy (y = 0-3) in a continuous microwave discharge flow tube, the CHx and SiHy species being formed by successive hydrogen-atom abstractions induced by fluorine atoms on methane and silane, respectively. Mass-selected ion yield and photoelectron spectra were recorded as a function of photon energy using a double imaging photoelectron/photoion coincidence spectrometer. The photoelectron spectrum enables the first direct experimental determinations of the X+ 4Σ− ← X 3Π and 1+ 2Π ← X 3Π adiabatic ionization energies of SiC (8.978(10) eV and 10.216(24) eV, respectively). Calculated spectra based on Franck-Condon factors are compared with the experimental spectra. These spectra were obtained by solving the rovibrational Hamiltonian, using the potential energy curves calculated at the multireference single and double configuration interaction level with Davidson correction (MRCI + Q) and the aug-cc-pV5Z basis set. MRCI + Q calculations including the core and core-valence electron correlation were performed using the aug-cc-pCV6Z basis set to predict the spectroscopic properties of the six lowest electronic states of SiC+. Complete basis set extrapolations and relativistic energy corrections were also included in the determination of the energy differences characterizing the photoionization process. Using our experimental and theoretical results, we derived semi-experimental values for the five lowest ionization energies of SiC. © 2023 The Royal Society of Chemistry.
BibTeX:
@article{Gans2023,
  author = {Gans, B. and Liévin, J. and Halvick, P. and Chen, N.L. and Boyé-Péronne, S. and Hartweg, S. and Garcia, G.A. and Loison, J.-C.},
  title = {Single-photon ionization of SiC in the gas phase: experimental and ab initio characterization of SiC+},
  journal = {Physical Chemistry Chemical Physics},
  year = {2023},
  volume = {25},
  number = {35},
  pages = {23568 – 23578},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1039/d3cp02775a}
}
Glorieux R, Hays B, Bogomolov A, Herman M, Vanfleteren T, Moazzen-Ahmadi N and Lauzin C (2023), "Understanding the high-resolution spectral signature of the N2-H2O van der Waals complex in the 2OH stretch region", Journal of Chemical Physics. Vol. 158(22)
Abstract: We present the observation of the N2-H2O van der Waals complex in the 2OH stretch overtone region. The high-resolution jet cooled spectra were measured using a sensitive continuous wave cavity ringdown spectrometer. Several bands were observed and vibrationally assigned in terms of ν1, ν2, and ν3, the vibrational quantum numbers of the isolated H2O molecule, as ( ν 1 ′ ν 2 ′ ν 3 ′ ) ← ( ν 1 ″ ν 2 ″ ν 3 ″ ) = ( 200 ) ← ( 000 ) and (101) ← (000). A combination band involving the excitation of the in-plane bending motion of N2 and the (101) vibration of water is also reported. The spectra were analyzed using a set of four asymmetric top rotors, each associated with a nuclear spin isomer. Several local perturbations of the (101) vibrational state were observed. These perturbations were assigned to the presence of the nearby (200) vibrational state and to the combination of (200) with intermolecular modes. © 2023 Author(s).
BibTeX:
@article{Glorieux2023,
  author = {Glorieux, R. and Hays, B.M. and Bogomolov, A.S. and Herman, M. and Vanfleteren, T. and Moazzen-Ahmadi, N. and Lauzin, C.},
  title = {Understanding the high-resolution spectral signature of the N2-H2O van der Waals complex in the 2OH stretch region},
  journal = {Journal of Chemical Physics},
  year = {2023},
  volume = {158},
  number = {22},
  doi = {10.1063/5.0150823}
}
Jönsson P, Gaigalas G, Fischer CF, Bieroń J, Grant IP, Brage T, Ekman J, Godefroid M, Grumer J, Li J and Li W (2023), "GRASP Manual for Users", Atoms. Vol. 11(4)
Abstract: grasp is a software package in Fortran 95, adapted to run in parallel under MPI, for research in atomic physics. The basic premise is that, given a wave function, any observed atomic property can be computed. Thus, the first step is always to determine a wave function. Different properties challenge the accuracy of the wave function in different ways. This software is distributed under the MIT Licence. © 2023 by the authors.
BibTeX:
@article{Joensson2023,
  author = {Jönsson, Per and Gaigalas, Gediminas and Fischer, Charlotte Froese and Bieroń, Jacek and Grant, Ian P. and Brage, Tomas and Ekman, Jörgen and Godefroid, Michel and Grumer, Jon and Li, Jiguang and Li, Wenxian},
  title = {GRASP Manual for Users},
  journal = {Atoms},
  year = {2023},
  volume = {11},
  number = {4},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atoms11040068}
}
Jönsson P, Godefroid M, Gaigalas G, Ekman J, Grumer J, Li W, Li  J, Brage T, Grant IP, Bieroń J and Fischer CF (2023), "An Introduction to Relativistic Theory as Implemented in GRASP", Atoms. Vol. 11(1)
Abstract: Computational atomic physics continues to play a crucial role in both increasing the understanding of fundamental physics (e.g., quantum electrodynamics and correlation) and producing atomic data for interpreting observations from large-scale research facilities ranging from fusion reactors to high-power laser systems, space-based telescopes and isotope separators. A number of different computational methods, each with their own strengths and weaknesses, is available to meet these tasks. Here, we review the relativistic multiconfiguration method as it applies to the General Relativistic Atomic Structure Package [grasp2018, C. FroeseFischer, G. Gaigalas, P. Jönsson, J. Bieroń, Comput. Phys. Commun. (2018). DOI: 10.1016/j.cpc.2018.10.032]. To illustrate the capacity of the package, examples of calculations of relevance for nuclear physics and astrophysics are presented. © 2022 by the authors.
BibTeX:
@article{Joensson2023a,
  author = {Jönsson, Per and Godefroid, Michel and Gaigalas, Gediminas and Ekman, Jörgen and Grumer, Jon and Li, Wenxian and Li , Jiguang and Brage, Tomas and Grant, Ian P. and Bieroń, Jacek and Fischer, Charlotte Froese},
  title = {An Introduction to Relativistic Theory as Implemented in GRASP},
  journal = {Atoms},
  year = {2023},
  volume = {11},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atoms11010007}
}
Lam L, George M, Gardoll S, Safieddine S, Whitburn S and Clerbaux C (2023), "Tropical Cyclone Detection from the Thermal Infrared Sensor IASI Data Using the Deep Learning Model YOLOv3", Atmosphere. Vol. 14(2)
Abstract: Tropical cyclone (TC) detection is essential to mitigate natural disasters, as TCs can cause significant damage to life, infrastructure and economy. In this study, we applied the deep learning object detection model YOLOv3 to detect TCs in the North Atlantic Basin, using data from the Thermal InfraRed (TIR) Atmospheric Sounding Interferometer (IASI) onboard the Metop satellites. IASI measures the outgoing TIR radiation of the Earth-Atmosphere. For the first time, we provide a proof of concept of the possibility of constructing images required by YOLOv3 from a TIR remote sensor that is not an imager. We constructed a dataset by selecting 50 IASI radiance channels and using them to create images, which we labeled by constructing bounding boxes around TCs using the hurricane database HURDAT2. We trained the YOLOv3 on two settings, first with three “best” selected channels, then using an autoencoder to exploit all 50 channels. We assessed its performance with the Average Precision (AP) metric at two different intersection over union (IoU) thresholds (0.1 and 0.5). The model achieved promising results with AP at IoU threshold 0.1 of 78.31%. Lower performance was achieved with IoU threshold 0.5 (31.05%), showing the model lacks precision regarding the size and position of the predicted boxes. Despite that, we show YOLOv3 demonstrates great potential for TC detection using TIR instruments data. © 2023 by the authors.
BibTeX:
@article{Lam2023,
  author = {Lam, Lisa and George, Maya and Gardoll, Sébastien and Safieddine, Sarah and Whitburn, Simon and Clerbaux, Cathy},
  title = {Tropical Cyclone Detection from the Thermal Infrared Sensor IASI Data Using the Deep Learning Model YOLOv3},
  journal = {Atmosphere},
  year = {2023},
  volume = {14},
  number = {2},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atmos14020215}
}
Li Y, Jönsson P, Godefroid M, Gaigalas G, Bieroń J, Marques JP, Indelicato P and Chen C (2023), "Independently Optimized Orbital Sets in GRASP—The Case of Hyperfine Structure in Li I", Atoms. Vol. 11(1)
Abstract: In multiconfiguration Dirac–Hartree–Fock (MCDHF) calculations, there is a strong coupling between the localization of the orbital set and the configuration state function (CSF) expansion used to determine it. Furthermore, it is well known that an orbital set resulting from calculations, including CSFs describing core–core correlation and other effects, which aims to lower the weighted energies of a number of targeted states as much as possible, may be inadequate for building CSFs that account for correlation effects that are energetically unimportant but decisive for computed properties, e.g., hyperfine structures or transition rates. This inadequacy can be traced in irregular or oscillating convergence patterns of the computed properties as functions of the increasing orbital set. In order to alleviate the above problems, we propose a procedure in which the orbital set is obtained by merging several separately optimized, and mutually non-orthogonal, orbital sets. This computational strategy preserves the advantages of capturing electron correlation on the total energy through the variational MCDHF method and allows to target efficiently the correlation effects on the considered property. The orbital sets that are merged are successively orthogonalized against each other to retain orthonormality. The merged orbital set is used to build CSFs that efficiently lower the energy and also adequately account for the correlation effects that are important for the property. We apply the procedure to compute the hyperfine structure constants for the (Formula presented.) and (Formula presented.) states in (Formula presented.) Li and show that it leads to considerably improved convergence patterns with respect to the increasing orbital set compared to standard calculations based on a single orbital set, energy-optimized in the variational procedure. The perspectives of the new procedure are discussed in a broader context in the summary. © 2022 by the authors.
BibTeX:
@article{Li2023a,
  author = {Li, Yanting and Jönsson, Per and Godefroid, Michel and Gaigalas, Gediminas and Bieroń, Jacek and Marques, José Pires and Indelicato, Paul and Chen, Chongyang},
  title = {Independently Optimized Orbital Sets in GRASP—The Case of Hyperfine Structure in Li I},
  journal = {Atoms},
  year = {2023},
  volume = {11},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atoms11010004}
}
Li Y, Li J, Song C, Zhang C, Si R, Wang K, Godefroid M, Gaigalas G, Jönsson P and Chen C (2023), "Performance Tests and Improvements on the rmcdhf and rci Programs of GRASP", Atoms. Vol. 11(1)
Abstract: The latest published version of GRASP (General-purpose Relativistic Atomic Structure Package), i.e., GRASP2018, retains a few suboptimal subroutines/algorithms, which reflect the limited memory and file storage of computers available in the 1980s. Here we show how the efficiency of the relativistic self-consistent-field (SCF) procedure of the multiconfiguration-Dirac–Hartree–Fock (MCDHF) method and the relativistic configuration-interaction (RCI) calculations can be improved significantly. Compared with the original GRASP codes, the present modified version reduces the CPU times by factors of a few tens or more. The MPI performances for all the original and modified codes are carefully analyzed. Except for diagonalization, all computational processes show good MPI scaling. © 2023 by the authors.
BibTeX:
@article{Li2023,
  author = {Li, Yanting and Li, Jinqing and Song, Changxian and Zhang, Chunyu and Si, Ran and Wang, Kai and Godefroid, Michel and Gaigalas, Gediminas and Jönsson, Per and Chen, Chongyang},
  title = {Performance Tests and Improvements on the rmcdhf and rci Programs of GRASP},
  journal = {Atoms},
  year = {2023},
  volume = {11},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atoms11010012}
}
Li YT, Wang K, Si R, Godefroid M, Gaigalas G, Chen CY and Jönsson P (2023), "Reducing the computational load – atomic multiconfiguration calculations based on configuration state function generators", Computer Physics Communications. Vol. 283
Abstract: In configuration interaction (CI) calculations the atomic wave functions are given as expansions over configuration state functions (CSFs) built on relativistic one-electron orbitals. The expansion coefficients of the configuration state functions are obtained by constructing and diagonalizing the Hamiltonian matrix. Here we show how a regrouping of the configuration state functions and the introduction of configuration state function generators (CSFGs) allow for a substantial reduction of the computational load in relativistic CI calculations. The computational methodology based on configuration state function generators, recently implemented in the General Relativistic Atomic Structure package (GRASP2018, FroeseFischer et al. (2019) [16]), is applied to a number of atomic systems and correlation models with increasing sets of one-electron orbitals. We demonstrate a reduction of the CPU time with factors between 10 and 14 for the largest CI calculations. The inclusion of the Breit interaction into the calculations is time consuming. By applying restrictions on the Breit integrals we show that it is possible to further reduce the CPU times with factors between 2 and 3, with negligible changes to the computed excitation energies. We also demonstrate that the introduction of configuration state function generators allows for efficient a priori condensation techniques, with reductions of the expansions sizes with factors between 1.5 and 2.5 and the CPU time with factors between 2.5 and 4.5, again with negligible changes to the excitation energies. In total we demonstrate reductions of the CPU time with factors up to 68 for CI calculations based on configuration state function generators, restrictions on the Breit integrals and with a priori condensed expansions compared to ordinary CI calculations without restrictions on the Breit integrals and with full expansions. Further perspectives of the new methodology based on configuration state function generators are given. © 2022
BibTeX:
@article{Li2023b,
  author = {Li, Yan Ting and Wang, Kai and Si, Ran and Godefroid, Michel and Gaigalas, Gediminas and Chen, Chong Yang and Jönsson, Per},
  title = {Reducing the computational load – atomic multiconfiguration calculations based on configuration state function generators},
  journal = {Computer Physics Communications},
  year = {2023},
  volume = {283},
  doi = {10.1016/j.cpc.2022.108562}
}
Noppen L, Clarisse L, Tack F, Ruhtz T, Merlaud A, VanDamme M, vanRoozendael M, Schuettemeyer D and Coheur P (2023), "Constraining industrial ammonia emissions using hyperspectral infrared imaging", Remote Sensing of Environment. Vol. 291
Abstract: Atmospheric emissions of reactive nitrogen in the form of nitrogen dioxide (NO2) and ammonia (NH3) worsen air quality and upon deposition, dramatically affect the environment. Recent infrared satellite measurements have revealed that NH3 emitted by industries are an important and underestimated emission source. Yet, to assess these emissions, current satellite sounders are severely limited by their spatial resolution. In this paper, we analyse measurement data recorded in a series of imaging surveys that were conducted over industries in the Greater Berlin area (Germany). On board the aircraft were the Telops Hyper-Cam LW, targeting NH3 measurements in the longwave infrared at a resolution of 4 m and the SWING+ spectrometer targeting NO2 measurements in the UV–Vis at a resolution of 180 m. Two flights were carried out over German's largest production facility of synthetic NH3, urea and other fertilizers. In both cases, a large NH3 plume was observed originating from the factory. Using a Gaussian plume model to take into account plume rise and dispersion, coupled with well-established radiative transfer and inverse methods, we retrieve vertical column densities. From these, we calculate NH3 emission fluxes using the integrated mass enhancement and cross-sectional flux methods, yielding consistent emissions of the order of 2200 t yr−1 for both flights, assuming constant fluxes across the year. These estimates are about five times larger than those reported in the European Pollutant Release and Transfer Register (E-PRTR) for this plant. In the second campaign, a co-emitted NO2 plume was measured, likely related to the production of nitric acid at the plant. A third flight was carried out over an area comprising the cities of Staßfurt and Bernburg. Several small NH3 plumes were seen, one over a production facility of mineral wool insulation, one over a sugar factory and two over the soda ash plants in Staßfurt and Bernburg. A fifth and much larger plume was seen to originate from the sedimentation basins associated with the soda ash plant in Staßfurt, indicating rapid volatilization of ammonium rich effluents. We use the different measurement campaigns to simulate measurements of Nitrosat, a potential future satellite sounder dedicated to the sounding of reactive nitrogen at a resolution of 500 m. We demonstrate that such measurements would allow accurately constraining emissions in a single overpass, overcoming a number of important drawbacks of current satellite sounders. © 2023
BibTeX:
@article{Noppen2023,
  author = {Noppen, Lara and Clarisse, Lieven and Tack, Frederik and Ruhtz, Thomas and Merlaud, Alexis and VanDamme, Martin and vanRoozendael, Michel and Schuettemeyer, Dirk and Coheur, Pierre},
  title = {Constraining industrial ammonia emissions using hyperspectral infrared imaging},
  journal = {Remote Sensing of Environment},
  year = {2023},
  volume = {291},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.rse.2023.113559}
}
Ossohou M, Hickman JE, Clarisse L, Coheur P-F, VanDamme M, Adon M, Yoboué V, Gardrat E, Alvès MD and Galy-Lacaux C (2023), "Trends and seasonal variability in ammonia across major biomes in western and central Africa inferred from long-Term series of ground-based and satellite measurements", Atmospheric Chemistry and Physics. Vol. 23(16), pp. 9473 – 9494.
Abstract: Ammonia (NH3) is the most abundant alkaline component in the atmosphere. Changes in NH3 concentrations have important implications for atmospheric chemistry, air quality, and ecosystem integrity. We present a long-Term ammonia (NH3) assessment in the western and central African regions within the framework of the International Network to study Deposition and Atmospheric chemistry in Africa (INDAAF) programme. We analyse seasonal variations and trends in NH3 concentrations and total column densities along an African ecosystem transect spanning dry savannas in Banizoumbou, Niger, and Katibougou, Mali; wet savannas in Djougou, Benin, and Lamto, Cote d'Ivoire; and forests in Bomassa, Republic of the Congo, and Zoétélé, Cameroon. We use a 21-year record of observations (1998-2018) from INDAAF passive samplers and an 11-year record of observations (2008-2018) of atmospheric vertical column densities from the Infrared Atmospheric Sounding Interferometer (IASI) to evaluate NH3 ground-based concentrations and total column densities, respectively. Climatic data (air temperature, rainfall amount, and leaf area index), as well as ammonia emission data of biomass combustion from the fourth version of the Global Fire Emissions Database (GFED4) and anthropogenic sources from the Community Emissions Data System (CEDS), were compared with total NH3 concentrations and total columns over the same periods. Annual mean ground-based NH3 concentrations are around 5.7-5.8g€¯ppb in dry savannas, 3.5-4.7g€¯ppb in wet savannas, and 3.4-5.6g€¯ppb in forests. Annual IASI NH3 total column densities are 10.0-10.7g 1015gcm-2 in dry savanna, 16.0-20.9g 1015gcm-2 in wet savanna, and 12.4-13.8g 1015gcm-2 in forest stations. Non-parametric statistical Mann-Kendall trend tests applied to annual data show that ground-based NH3 concentrations increase at Bomassa (+2.56g yr-1) but decrease at Zoétélé (-2.95g yr-1) over the 21-year period. The 11-year period of IASI NH3 total column density measurements show yearly increasing trends at Katibougou (+3.46g yr-1), Djougou (+2.24g yr-1), and Zoétélé (+3.42g yr-1). From the outcome of our investigation, we conclude that air temperature, leaf area index, and rainfall combined with biomass burning, agricultural, and residential activities are the key drivers of atmospheric NH3 in the INDAAF stations. The results also show that the drivers of trends are (1) agriculture in the dry savanna of Katibougou; (2) air temperature and agriculture in the wet savanna of Djougou and Lamto; and (3) leaf area index, air temperature, residential, and agriculture in the forest of Bomassa. © 2023 Money Ossohou et al.
BibTeX:
@article{Ossohou2023,
  author = {Ossohou, Money and Hickman, Jonathan Edward and Clarisse, Lieven and Coheur, Pierre-François and VanDamme, Martin and Adon, Marcellin and Yoboué, Véronique and Gardrat, Eric and Alvès, Maria Dias and Galy-Lacaux, Corinne},
  title = {Trends and seasonal variability in ammonia across major biomes in western and central Africa inferred from long-Term series of ground-based and satellite measurements},
  journal = {Atmospheric Chemistry and Physics},
  year = {2023},
  volume = {23},
  number = {16},
  pages = {9473 – 9494},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-23-9473-2023}
}
Plattner P, Wood E, Al Ayoubi L, Beliuskina O, Bissell M, Blaum K, Campbell P, Cheal B, De Groote R, Devlin C, Eronen T, Filippin L, Garcia Ruiz R, Ge Z, Geldhof S, Gins W, Godefroid M, Heylen H, Hukkanen M, Imgram P, Jaries A, Jokinen A, Kanellakopoulos A, Kankainen A, Kaufmann S, König K, Koszorús Á, Kujanpää S, Lechner S, Malbrunot-Ettenauer S, Müller P, Mathieson R, Moore I, Nörtershäuser W, Nesterenko D, Neugart R, Neyens G, Ortiz-Cortes A, Penttilä H, Pohjalainen I, Raggio A, Reponen M, Rinta-Antila S, Rodríguez L, Romero J, Sánchez R, Sommer F, Stryjczyk M, Virtanen V, Xie L, Xu Z, Yang X and Yordanov D (2023), "Nuclear Charge Radius of Al 26m and Its Implication for Vud in the Quark Mixing Matrix", Physical Review Letters. Vol. 131(22)
Abstract: Collinear laser spectroscopy was performed on the isomer of the aluminium isotope Al26m. The measured isotope shift to Al27 in the 3s23p P3/2○2→3s24s S1/22 atomic transition enabled the first experimental determination of the nuclear charge radius of Al26m, resulting in Rc=3.130(15) fm. This differs by 4.5 standard deviations from the extrapolated value used to calculate the isospin-symmetry breaking corrections in the superallowed β decay of Al26m. Its corrected Ft value, important for the estimation of Vud in the Cabibbo-Kobayashi-Maskawa matrix, is thus shifted by 1 standard deviation to 3071.4(1.0) s. © 2023 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
BibTeX:
@article{Plattner2023,
  author = {Plattner, P. and Wood, E. and Al Ayoubi, L. and Beliuskina, O. and Bissell, M.L. and Blaum, K. and Campbell, P. and Cheal, B. and De Groote, R.P. and Devlin, C.S. and Eronen, T. and Filippin, L. and Garcia Ruiz, R.F. and Ge, Z. and Geldhof, S. and Gins, W. and Godefroid, M. and Heylen, H. and Hukkanen, M. and Imgram, P. and Jaries, A. and Jokinen, A. and Kanellakopoulos, A. and Kankainen, A. and Kaufmann, S. and König, K. and Koszorús, Á. and Kujanpää, S. and Lechner, S. and Malbrunot-Ettenauer, S. and Müller, P. and Mathieson, R. and Moore, I. and Nörtershäuser, W. and Nesterenko, D. and Neugart, R. and Neyens, G. and Ortiz-Cortes, A. and Penttilä, H. and Pohjalainen, I. and Raggio, A. and Reponen, M. and Rinta-Antila, S. and Rodríguez, L.V. and Romero, J. and Sánchez, R. and Sommer, F. and Stryjczyk, M. and Virtanen, V. and Xie, L. and Xu, Z.Y. and Yang, X.F. and Yordanov, D.T.},
  title = {Nuclear Charge Radius of Al 26m and Its Implication for Vud in the Quark Mixing Matrix},
  journal = {Physical Review Letters},
  year = {2023},
  volume = {131},
  number = {22},
  note = {All Open Access, Hybrid Gold Open Access},
  doi = {10.1103/PhysRevLett.131.222502}
}
Richard C, Boudon V, Manceron L, VanderAuwera J, Vinatier S, Bézard B and Houelle M (2023), "Self and N2 collisional broadening of far-infrared methane lines at low-temperature with application to Titan", Icarus. Vol. 404
Abstract: We report the measurement of broadening coefficients of pure rotational lines of methane at different pressure and temperature conditions. A total of 27 far-infrared spectra were recorded at the AILES beamline of the SOLEIL synchrotron at room-temperature, 200 K and 120 K, in a range of 10 to 800 mbar. Self and N2 broadening coefficients and temperature dependence exponents of methane pure rotational lines have been measured in the 73–136 cm−1 spectral range using multi-spectrum non-linear least squares fitting of Voigt profiles. These coefficients were used to model spectra of Titan that were compared to a selection of equatorial Cassini/CIRS spectra, showing a good agreement for a stratospheric methane mole fraction of (1.17 ± 0.08)%. © 2023 Elsevier Inc.
BibTeX:
@article{Richard2023,
  author = {Richard, C. and Boudon, V. and Manceron, L. and VanderAuwera, J. and Vinatier, S. and Bézard, B. and Houelle, M.},
  title = {Self and N2 collisional broadening of far-infrared methane lines at low-temperature with application to Titan},
  journal = {Icarus},
  year = {2023},
  volume = {404},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.icarus.2023.115692}
}
Ripak A, DeKreijger S, Sampaio RN, Vincent CA, Cauët É, Jabin I, Tambar UK, Elias B and Troian-Gautier L (2023), "Photosensitized activation of diazonium derivatives for C–B bond formation", Chem Catalysis. Vol. 3(2)
Abstract: Aryl diazonium salts are ubiquitous building blocks in chemistry, as they are useful radical precursors in organic synthesis as well as for the functionalization of solid materials. They can be reduced electrochemically or through a photo-induced electron transfer reaction. Here, we provide a detailed picture of the ground- and excited-state reactivity of a series of nine rare and earth-abundant photosensitizers with 13 aryl diazonium salts, which also included three macrocyclic calix[4]arene tetradiazonium salts. Nanosecond transient absorption spectroscopy confirmed the occurrence of excited-state electron transfer and was used to quantify cage-escape yields (i.e., the efficiency with which the formed radicals separate and escape the solvent cage). Cage-escape yields were large; they increased when the driving force for photo-induced electron transfer increased and also tracked with the C–N2+ bond cleavage propensity, among others. A photo-induced borylation reaction was then investigated with all the photosensitizers and proceeded with yields between 9% and 74%. © 2022 Elsevier Inc.
BibTeX:
@article{Ripak2023,
  author = {Ripak, Alexia and DeKreijger, Simon and Sampaio, Renato N. and Vincent, Cooper A. and Cauët, Émilie and Jabin, Ivan and Tambar, Uttam K. and Elias, Benjamin and Troian-Gautier, Ludovic},
  title = {Photosensitized activation of diazonium derivatives for C–B bond formation},
  journal = {Chem Catalysis},
  year = {2023},
  volume = {3},
  number = {2},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.checat.2022.100490}
}
Viatte C, Guendouz N, Dufaux C, Hensen A, Swart D, VanDamme M, Clarisse L, Coheur P and Clerbaux C (2023), "Measurement report: Ammonia in Paris derived from ground-based open-path and satellite observations", Atmospheric Chemistry and Physics. Vol. 23(24), pp. 15253 – 15267.
Abstract: Ammonia (NH3) is an important air pollutant which, as a precursor of fine particulate matter, raises public health concerns. This study analyzes 2.5 years of NH3 observations derived from ground-based (miniDOAS; differential optical absorption spectroscopy) and satellite (IASI; Infrared Atmospheric Sounding Interferometer) remote sensing instruments to quantify, for the first time, temporal variabilities (from interannual to diurnal) in NH3 concentrations in Paris. The IASI and miniDOAS datasets are found to be in relatively good agreement (R>0.70) when atmospheric NH3 concentrations are high and driven by regional agricultural activities. Over the investigated period (January 2020–June 2022), NH3 average concentrations in Paris measured by the miniDOAS and IASI are 2.23 µg m−3 and 7.10 × 1015 molec. cm−2, respectively, which are lower than or equivalent to those documented in other urban areas. The seasonal and monthly variabilities in NH3 concentrations in Paris are driven by sporadic agricultural emissions influenced by meteorological conditions, with NH3 concentrations in spring up to 2 times higher than in other seasons. The potential source contribution function (PSCF) reveals that the close (100–200 km) east and northeast regions of Paris constitute the most important potential emission source areas of NH3 in the megacity. Weekly cycles of NH3 derived from satellite and ground-based observations show different ammonia sources in Paris. In spring, agriculture has a major influence on ammonia concentrations, and, in the other seasons, multi-platform observations suggest that ammonia is also controlled by traffic-related emissions. In Paris, the diurnal cycle of NH3 concentrations is very similar to the one of NO2, with morning enhancements coincident with intensified road traffic. NH3 evening enhancements synchronous with rush hours are also monitored in winter and fall. NH3 concentrations measured during the weekends are consistently lower than NH3 concentrations measured during weekdays in summer and fall. This is further evidence of a significant traffic source of NH3 in Paris. © Author(s) 2023. This work is distributed under the Creative Commons Attribution 4.0 License.
BibTeX:
@article{Viatte2023,
  author = {Viatte, Camille and Guendouz, Nadir and Dufaux, Clarisse and Hensen, Arjan and Swart, Daan and VanDamme, Martin and Clarisse, Lieven and Coheur, Pierre and Clerbaux, Cathy},
  title = {Measurement report: Ammonia in Paris derived from ground-based open-path and satellite observations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2023},
  volume = {23},
  number = {24},
  pages = {15253 – 15267},
  doi = {10.5194/acp-23-15253-2023}
}
VuVan A, Boynard A, Prunet P, Jolivet D, Lezeaux O, Henry P, Camy-Peyret C, Clarisse L, Franco B, Coheur P-F and Clerbaux C (2023), "Near-real-Time detection of unexpected atmospheric events using principal component analysis on the Infrared Atmospheric Sounding Interferometer (IASI) radiances", Atmospheric Measurement Techniques. Vol. 16(8), pp. 2107 – 2127.
Abstract: The three Infrared Atmospheric Sounding Interferometer (IASI) instruments on board the Metop family of satellites have been sounding the atmospheric composition since 2006. More than 30 atmospheric gases can be measured from the IASI radiance spectra, allowing the improvement of weather forecasting and the monitoring of atmospheric chemistry and climate variables. The early detection of extreme events such as fires, pollution episodes, volcanic eruptions, or industrial releases is key to take safety measures to protect the inhabitants and the environment in the impacted areas. With its near-real-Time observations and good horizontal coverage, IASI can contribute to the series of monitoring systems for the systematic and continuous detection of exceptional atmospheric events in order to support operational decisions. In this paper, we describe a new approach to the near-real-Time detection and characterization of unexpected events, which relies on the principal component analysis (PCA) of IASI radiance spectra. By analyzing both the IASI raw and compressed spectra, we applied a PCA-granule-based method on various past, well-documented extreme events such as volcanic eruptions, fires, anthropogenic pollution, and industrial accidents. We demonstrate that the method is well suited to the detection of spectral signatures for reactive and weakly absorbing gases, even for sporadic events. Consistent long-Term records are also generated for fire and volcanic events from the available IASI/Metop-B data record. The method is running continuously, delivering email alerts on a routine basis, using the near-real-Time IASI L1C radiance data. It is planned to be used as an online tool for the early and automatic detection of extreme events, which was not done before. © Copyright:
BibTeX:
@article{VuVan2023,
  author = {VuVan, Adrien and Boynard, Anne and Prunet, Pascal and Jolivet, Dominique and Lezeaux, Olivier and Henry, Patrice and Camy-Peyret, Claude and Clarisse, Lieven and Franco, Bruno and Coheur, Pierre-François and Clerbaux, Cathy},
  title = {Near-real-Time detection of unexpected atmospheric events using principal component analysis on the Infrared Atmospheric Sounding Interferometer (IASI) radiances},
  journal = {Atmospheric Measurement Techniques},
  year = {2023},
  volume = {16},
  number = {8},
  pages = {2107 – 2127},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-16-2107-2023}
}
Wang R, Pan D, Guo X, Sun K, Clarisse L, VanDamme M, Coheur P-F, Clerbaux C, Puchalski M and Zondlo MA (2023), "Bridging the spatial gaps of the Ammonia Monitoring Network using satellite ammonia measurements", Atmospheric Chemistry and Physics. Vol. 23(20), pp. 13217 – 13234.
Abstract: Ammonia (NH3) is a key precursor to fine particulate matter (PM2.5) and a primary form of reactive nitrogen. The limited number of NH3 observations hinders the further understanding of its impacts on air quality, climate, and biodiversity. Currently, NH3 ground monitoring networks are few and sparse across most of the globe, and even in the most established networks, large spatial gaps exist between sites and only a few sites have records that span longer than a decade. Satellite NH3 observations can be used to discern trends and fill spatial gaps in networks, but many factors influence the syntheses of the vastly different spatiotemporal scales between surface network and satellite measurements. To this end, we intercompared surface NH3 data from the Ammonia Monitoring Network (AMoN) and satellite NH3 total columns from the Infrared Atmospheric Sounding Interferometer (IASI) in the contiguous United States (CONUS) and then performed trend analyses using both datasets. We explored the sensitivity of correlations between the two datasets to factors such as satellite data availability and distribution over the surface measurement period, as well as agreement within selected spatial and temporal windows. Given the short lifetime of atmospheric ammonia and consequently sharp gradients, smaller spatial windows show better agreement than larger ones except in areas of relatively uniform, low concentrations where large windows and more satellite measurements improve the signal-to-noise ratio. A critical factor in the comparison is having satellite measurements across most of the measurement period of the monitoring site. When IASI data are available for at least 80 % of the days of AMoN's 2-week sampling period within a 25 km spatial window of a given site, IASI NH3 column concentrations and the AMoN NH3 surface concentrations have a correlation of 0.74, demonstrating the feasibility of using satellite NH3 columns to bridge the spatial gaps existing in the surface network NH3 concentrations. Both IASI and AMoN show increasing NH3 concentrations across the CONUS (median: 6.8 %yr-1 versus 6.7 %yr-1) in the last decade (2008-2018), suggesting the NH3 will become a greater contributor to nitrogen deposition. NH3 trends at AMoN sites are correlated with IASI NH3 trends (r Combining double low line 0.66) and show similar spatial patterns, with the highest increases in the Midwest and eastern US. In spring and summer, increases in NH3 were larger than 10 %yr-1 in the eastern US and Midwest (cropland dominated) and the western US (pastureland dominated), respectively. NH3 hotspots are defined as regions where the IASI NH3 column is larger than the 95th percentile of the 11-year CONUS map (6.7 × 1015 molec.cm-2), they also experience increasing concentrations over time, with a median of NH3 trend of 4.7 %yr-1. IASI data show large NH3 increases in urban areas (8.1 %yr-1), including 8 of the top 10 most populous regions in the CONUS, where AMoN sites are sparse. A comparison between IASI NH3 concentration trends and state-level NH3 emission trends is then performed to reveal that positive correlations exist in states with strong agricultural NH3 emissions, while there are negative correlations in states with low NH3 emissions and large NOx emissions, suggesting the different roles of emission and partitioning in NH3 increases. The increases in NH3 could have detrimental effects on nearby eco-sensitive regions through nitrogen deposition and on aerosol chemistry in the densely populated urban areas, and therefore they should be carefully monitored and studied. © 2023 Rui Wang et al.
BibTeX:
@article{Wang2023,
  author = {Wang, Rui and Pan, Da and Guo, Xuehui and Sun, Kang and Clarisse, Lieven and VanDamme, Martin and Coheur, Pierre-François and Clerbaux, Cathy and Puchalski, Melissa and Zondlo, Mark A.},
  title = {Bridging the spatial gaps of the Ammonia Monitoring Network using satellite ammonia measurements},
  journal = {Atmospheric Chemistry and Physics},
  year = {2023},
  volume = {23},
  number = {20},
  pages = {13217 – 13234},
  doi = {10.5194/acp-23-13217-2023}
}
Wizenberg T, Strong K, Jones D, Lutsch E, Mahieu E, Franco B and Clarisse L (2023), "Exceptional Wildfire Enhancements of PAN, C2H4, CH3OH, and HCOOH Over the Canadian High Arctic During August 2017", Journal of Geophysical Research: Atmospheres. Vol. 128(10)
Abstract: Extreme enhancements in the total columns of carbon monoxide (CO), peroxyacetyl nitrate (PAN), ethylene (C2H4), methanol (CH3OH), and formic acid (HCOOH) were observed over the Canadian high Arctic during the period of 17–22 August 2017 by a ground-based Fourier transform infrared (FTIR) spectrometer at Eureka, Nunavut (80.05°N, 86.42°W), and by the Infrared Atmospheric Sounding Interferometer (IASI) satellite instruments. These enhancements have been attributed to wildfires in British Columbia (BC) and the Northwest Territories (NWT) of Canada, and represent the largest short-term perturbations of PAN, C2H4, and HCOOH above ambient concentrations over the 14-year (2006–2020) Eureka time-series. Enhancement ratios, emission ratios, and emission factors relative to CO were calculated for all species for both FTIR and IASI observations. The C2H4 and HCOOH emission factors are significantly larger than previous studies, suggesting unusually high emissions from these fires. The wildfire plumes were also simulated using the GEOS-Chem model. Initial GEOS-Chem simulations displayed a severe under-estimation relative to observations for these fire plumes resulting from the injection height scheme of the model. Sensitivity tests highlighted that injection heights of 12.5 km for BC (based on previous studies) and 10 km for the NWT fires yielded the strongest correlations with ground-based measurements. Applying these injection heights to the model significantly improves the simulated plume transport and agreement with ground- and space-based observations. GEOS-Chem was also used to estimate the magnitude of secondary in-plume production of CH3OH and HCOOH; it was found to be an important component (∼18%) of the enhanced HCOOH columns at Eureka. © 2023. The Authors.
BibTeX:
@article{Wizenberg2023,
  author = {Wizenberg, T. and Strong, K. and Jones, D.B.A. and Lutsch, E. and Mahieu, E. and Franco, B. and Clarisse, L.},
  title = {Exceptional Wildfire Enhancements of PAN, C2H4, CH3OH, and HCOOH Over the Canadian High Arctic During August 2017},
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2023},
  volume = {128},
  number = {10},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1029/2022JD038052}
}
Zeng Z-C, Lee L, Qi C, Clarisse L and VanDamme M (2023), "Optimal estimation retrieval of tropospheric ammonia from the Geostationary Interferometric Infrared Sounder on board FengYun-4B", Atmospheric Measurement Techniques. Vol. 16(15), pp. 3693 – 3713.
Abstract: Atmospheric ammonia (NH3) is a reactive nitrogen compound that pollutes our environment and threatens public health. Monitoring the spatial and temporal variations is important for quantifying its emissions and depositions and evaluating the strategies for managing anthropogenic sources of NH3. In this study, we present an NH3 retrieval algorithm based on the optimal estimation method for the Geostationary Interferometric Infrared Sounder (GIIRS) on board China's FengYun-4B satellite (FY-4B/GIIRS). In particular, we examine the information content based on the degree of freedom for signal (DOFS) in retrieving the diurnal NH3 in East Asia, with a focus on two source regions including the North China Plain and North India. Our retrieval is based on the FengYun Geostationary satellite Atmospheric Infrared Retrieval (FY-GeoAIR) algorithm and exploits the strong NH3 absorption window of 955-975ĝ€¯cm-1. Retrieval results using FY-4B/GIIRS spectra from July to December 2022 show that the DOFS for the majority ranges from 0 to 1.0, mainly depending on the thermal contrast (TC) defined as the temperature difference between the surface and the lowest atmospheric layer. Consistent with retrievals from low-Earth-orbit (LEO) infrared sounders, the detection sensitivity, as quantified by the averaging kernel (AK) matrix, peaks in the lowest 2ĝ€¯km atmospheric layers. The DOFS and TC are highly correlated, resulting in a typical "butterfly"shape. That is, the DOFS increases when TC becomes either more positive or more negative. The NH3 columns from FY-4B/GIIRS exhibit significant diurnal cycles that are consistent with the day-night gradient from the collocated IASI retrievals in the North China Plain and North India for the averages in July-August, September-October, and November-December, respectively. A collocated point-by-point intercomparison with the IASI NH3 dataset shows generally good agreement with a small systematic difference in the summer months that may be attributed to the slight difference in a priori profiles. This study demonstrates the capability of FY-4B/GIIRS in capturing the diurnal NH3 changes in East Asia, which will have the potential to improve regional and global air quality and climate research. © Copyright:
BibTeX:
@article{Zeng2023,
  author = {Zeng, Zhao-Cheng and Lee, Lu and Qi, Chengli and Clarisse, Lieven and VanDamme, Martin},
  title = {Optimal estimation retrieval of tropospheric ammonia from the Geostationary Interferometric Infrared Sounder on board FengYun-4B},
  journal = {Atmospheric Measurement Techniques},
  year = {2023},
  volume = {16},
  number = {15},
  pages = {3693 – 3713},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-16-3693-2023}
}
Aerts A, Kockaert P, Gorza S-P, Brown A, VanderAuwera J and Vaeck N (2022), "Laser control of a dark vibrational state of acetylene in the gas phase - Fourier transform pulse shaping constraints and effects of decoherence", Journal of Chemical Physics. Vol. 156(8)
Abstract: We propose a methodology to tackle the laser control of a non-stationary dark ro-vibrational state of acetylene (C2H2), given realistic experimental limitations in the 7.7 μm (1300 cm-1) region. Simulations are performed using the Lindblad master equation, where the so-called Lindblad parameters are used to describe the effect of the environment in the dilute gas phase. A phenomenological representation of the parameters is used, and they are extracted from high-resolution spectroscopy line broadening data. An effective Hamiltonian is used for the description of the system down to the rotational level close to experimental accuracy. The quality of both the Hamiltonian and Lindblad parameters is assessed by a comparison of a calculated infrared spectrum with the available experimental data. A single shaped laser pulse is used to perform the control, where elements of optics and pulse shaping using masks are introduced with emphasis on experimental limitations. The optimization procedure, based on gradients, explicitly takes into account the experimental constraints. Control performances are reported for shaping masks of increasing complexity. Although modest performances are obtained, mainly due to the strong pulse shaping constraints, we gain insights into the control mechanism. This work is the first step toward the conception of a realistic experiment that will allow for population characterization and manipulation of a non-stationary vibrational "dark"state. Effects of the collisions on the laser control in the dilute gas phase, leading to decoherence in the molecular system, are clearly shown. © 2022 Author(s).
BibTeX:
@article{Aerts2022,
  author = {Aerts, Antoine and Kockaert, Pascal and Gorza, Simon-Pierre and Brown, Alex and VanderAuwera, Jean and Vaeck, Nathalie},
  title = {Laser control of a dark vibrational state of acetylene in the gas phase - Fourier transform pulse shaping constraints and effects of decoherence},
  journal = {Journal of Chemical Physics},
  year = {2022},
  volume = {156},
  number = {8},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/5.0080332}
}
Beale CA, Paulot F, Randles CA, Wang R, Guo X, Clarisse L, VanDamme M, Coheur P-F, Clerbaux C, Shephard MW, Dammers E, Cady-Pereira K and Zondlo MA (2022), "Large sub-regional differences of ammonia seasonal patterns over India reveal inventory discrepancies", Environmental Research Letters. Vol. 17(10)
Abstract: Ammonia (NH3) is a key precursor of haze particles and fine particulate matter (PM2.5) and its spatiotemporal variabilities are poorly constrained. In this study, we present measurements of NH3 over the Indian subcontinent region from the Infrared Atmospheric Sounder Interferometer (IASI) and Cross-track Infrared Sounder (CrIS) satellite instruments. This region exhibits a complex emission profile due to the number of varied sources, including crop burning, fossil fuel combustion, fertilizer application, livestock and industrial sources. Observations from the CrIS and IASI instruments are oversampled to a resolution of 0.02° × 0.02°. Five regions with distinct spatiotemporal NH3 profiles are determined using k-means clustering. Maximum NH3 columns are seen in July over the western India with column densities of 6.2 × 1017 mol cm−2 and 7.2 × 1017 mol cm−2 respectively for IASI and CrIS. The seasonality of measured NH3 columns show annual maxima occurring in spring in Eastern India and Bangladesh and in mid-summer for the western Indo-Gangetic plain. Our observational constraints suggest that the impact of local farming practices on NH3 emissions is not well captured in emission inventories such as Coupled Model Intercomparison Project Phase 6 (CMIP6), which exhibits peaks in the late spring and autumn. The spatial variability in the seasonal patterns of NH3 is also not captured by the single emissions profile used in CMIP6 for India. The high-resolution maps obtained from these measurements can be used to improve NH3 emission inventories in order to understand its sources for more accurate predictions of air quality in the Indian subcontinent. Our study points to the need for regionally specific emissions inventories for short-lived species such as NH3 that have heterogeneous emissions profiles due to specific agricultural practices and other emission source characteristics. © 2022 The Author(s). Published by IOP Publishing Ltd.
BibTeX:
@article{Beale2022,
  author = {Beale, Christopher A. and Paulot, Fabien and Randles, Cynthia A. and Wang, Rui and Guo, Xuehui and Clarisse, Lieven and VanDamme, Martin and Coheur, Pierre-François and Clerbaux, Cathy and Shephard, Mark W. and Dammers, Enrico and Cady-Pereira, Karen and Zondlo, Mark A.},
  title = {Large sub-regional differences of ammonia seasonal patterns over India reveal inventory discrepancies},
  journal = {Environmental Research Letters},
  year = {2022},
  volume = {17},
  number = {10},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1088/1748-9326/ac881f}
}
Bernath P, Dodangodage R and Liévin J (2022), "S-type Stars: LaO Line List for the B2ς+-X2ς+Band System", Astrophysical Journal. Vol. 933(1)
Abstract: LaO bands are a characteristic feature in the spectrum of cool S-type stars. La is made primarily by the s-process during the asymptotic giant branch phase of stellar evolution. The B2ς+-X2ς+ and A2Π-X2ς+ band systems can be used to determine the La abundances in cool S stars. The bands of the B2ς+-X2ς+ with v′ and v′′≤5 have been rotationally analyzed from an emission spectrum from a carbon furnace. Line strengths are calculated using an ab initio transition dipole function, corrected using experimental lifetimes. We provide a line list for the B2ς+-X2ς+ band system that can be used to determine La abundances. © 2022. The Author(s). Published by the American Astronomical Society.
BibTeX:
@article{Bernath2022a,
  author = {Bernath, P.F. and Dodangodage, R. and Liévin, J.},
  title = {S-type Stars: LaO Line List for the B2ς+-X2ς+Band System},
  journal = {Astrophysical Journal},
  year = {2022},
  volume = {933},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3847/1538-4357/ac731f}
}
Bernath PF, Johnson RM and Liévin J (2022), "Line lists for X3Σ− and a1Δ vibration-rotation bands of SO", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 290
Abstract: SO is found in several astronomical sources such as the atmospheres of Io and Venus. To complete our work on SO line lists, we used our previous fits for v = 0 to v = 6 for the X3Σ- state and v = 0–5 for the a1Δ state [JQSRT 272, 107772 (2021)] for line positions, and high-level ab initio calculations of electric dipole moments for line strengths for the vibration-rotation bands. LeRoy's RKR program was used to produce pointwise potential energy curves. N- and v-dependent dipole matrix elements were produced with LeRoy's LEVEL program and the final line lists were made with Western's PGOPHER program. All possible vibrational bands were calculated, and the line strengths included the Herman-Wallis effect caused by vibration-rotation interaction. © 2022
BibTeX:
@article{Bernath2022,
  author = {Bernath, Peter F. and Johnson, Ryan M. and Liévin, Jacques},
  title = {Line lists for X3Σ− and a1Δ vibration-rotation bands of SO},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2022},
  volume = {290},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2022.108317}
}
Bouillon M, Safieddine S, Whitburn S, Clarisse L, Aires F, Pellet V, Lezeaux O, Scott NA, Doutriaux-Boucher M and Clerbaux C (2022), "Time evolution of temperature profiles retrieved from 13 years of infrared atmospheric sounding interferometer (IASI) data using an artificial neural network", Atmospheric Measurement Techniques. Vol. 15(6), pp. 1779 – 1793.
Abstract: The three infrared atmospheric sounding interferometers (IASIs), launched in 2006, 2012, and 2018, are key instruments to weather forecasting, and most meteorological centres assimilate IASI nadir radiance data into atmospheric models to feed their forecasts. The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) recently released a reprocessed homogeneous radiance record for the whole IASI observation period, from which 13 years (2008-2020) of temperature profiles can be obtained. In this work, atmospheric temperatures at different altitudes are retrieved from IASI radiances measured in the carbon dioxide absorption bands (654-800 and 2250-2400gcm-1) by selecting the channels that are the most sensitive to the temperature at different altitudes. We rely on an artificial neural network (ANN) to retrieve atmospheric temperatures from a selected set of IASI radiances. We trained the ANN with IASI radiances as input and the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis version 5 (ERA5) as output. The retrieved temperatures were validated with ERA5, with in situ radiosonde temperatures from the Analysed RadioSoundings Archive (ARSA) network and with EUMETSAT temperatures retrieved from IASI radiances using a different method. Between 750 and 7ghPa, where IASI is most sensitive to temperature, a good agreement is observed between the three datasets: the differences between IASI on one hand and ERA5, ARSA, or EUMETSAT on the other hand are usually less than 0.5gK at these altitudes. At 2ghPa, as the IASI sensitivity decreases, we found differences up to 2gK between IASI and the three validation datasets. We then computed atmospheric temperature linear trends from atmospheric temperatures between 750 and 2ghPa. We found that in the past 13 years, there is a general warming trend of the troposphere that is more important at the poles and at mid-latitudes (0.5gK/decade at mid-latitudes, 1gK/decade at the North Pole). The stratosphere is globally cooling on average, except at the South Pole as a result of the ozone layer recovery and a sudden stratospheric warming in 2019. The cooling is most pronounced in the equatorial upper stratosphere (-1gK/decade). This work shows that ANN can be a powerful and simple tool to retrieve IASI temperatures at different altitudes in the upper troposphere and in the stratosphere, allowing us to construct a homogeneous and consistent temperature data record adapted to trend analysis. © 2022 Copernicus GmbH. All rights reserved.
BibTeX:
@article{Bouillon2022,
  author = {Bouillon, Marie and Safieddine, Sarah and Whitburn, Simon and Clarisse, Lieven and Aires, Filipe and Pellet, Victor and Lezeaux, Olivier and Scott, Noëlle A. and Doutriaux-Boucher, Marie and Clerbaux, Cathy},
  title = {Time evolution of temperature profiles retrieved from 13 years of infrared atmospheric sounding interferometer (IASI) data using an artificial neural network},
  journal = {Atmospheric Measurement Techniques},
  year = {2022},
  volume = {15},
  number = {6},
  pages = {1779 – 1793},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-15-1779-2022}
}
Cacciani P, Čermák P, VanderAuwera J and Campargue A (2022), "The ammonia absorption spectrum between 3900 and 4700 cm−1", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 277
Abstract: Room temperature absorption spectra of ammonia have been recorded by high-resolution Fourier transform spectroscopy in the range 3900-4700 cm–1 at four pressures (13, 46, 140, and 304 Pa). The investigated spectral region overlaps the important 2.3 µm atmospheric transparency window. 8419 absorption lines were retrieved from the recorded spectra. Line intensities range between 1 × 10−25 and 1.6 × 10−20 cm/molecule. The rovibrational assignments, relying on the position and intensity agreement with the C2018 theoretical line list (Coles et al. 2018), were validated by the systematic use of Lower State Combination Difference (LSCD) relations. 6052 transitions were assigned to 51 vibrational bands of the main isotopologue, 14NH3, and 625 transitions of the 15NH3 minor isotopologue were identified. Overall, the assigned transitions represent over 99.8% of the integrated absorption at room temperature in the region. The upper state empirical energy of a total of 2287 rovibrational levels of 14NH3 were derived. Among them, 1870 are newly reported. The achieved quality of the LSCD relations indicates that the accuracy of the derived energy levels is better than 0.001 cm−1. Comparison with the HITRAN2020 list shows that the present results will be valuable in improving the ammonia spectroscopic databases in the region, both in terms of completeness and accuracy of the line positions and line intensities. A recommended line list for ammonia in natural isotopic abundance is provided for the studied region. © 2021 Elsevier Ltd
BibTeX:
@article{Cacciani2022,
  author = {Cacciani, P. and Čermák, P. and VanderAuwera, J. and Campargue, A.},
  title = {The ammonia absorption spectrum between 3900 and 4700 cm−1},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2022},
  volume = {277},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2021.107961}
}
Cacciani P, Čermák P, VanderAuwera J and Campargue A (2022), "The ammonia absorption spectrum between 4700 and 5650 cm−1", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 292
Abstract: Room temperature absorption spectra of ammonia were recorded by high-resolution Fourier transform spectroscopy in the 4700–5600 cm−1 range at four pressures (13, 46, 140, and 304 Pa). Additionally, we use an existing Kitt Peak spectrum to extend the analysis up to 5650 cm−1. In total, 9110 absorption lines with intensity ranging from 1×10−25 to 1.6×10−20 cm/molecule were retrieved, for the two principal isotopologues. Another Kitt Peak spectrum was used to identify 505 15NH3 transitions within the experimental line list. The rovibrational assignments of the 14NH3 lines relied on the position and intensity agreement with the C2018 theoretical line list (Coles et al. JQSRT 2018;219 199–212) and were validated by the systematic use of Lower State Combination Difference (LSCD) relations. In the process, a number of intensity transfer between nearby transitions were identified. Finally, 6562 transitions were assigned to 61 vibrational bands of the main isotopologue, 14NH3, representing 98.85% of the C2018 integrated absorption at room temperature in the region. The upper state empirical energy of a total of 2215 rovibrational levels of 14NH3 were derived. Most of them are newly reported. The comparison with the current HITRAN2020 list is discussed. A recommended line list for ammonia in natural isotopic abundance is provided for the studied region. © 2022 Elsevier Ltd
BibTeX:
@article{Cacciani2022a,
  author = {Cacciani, P. and Čermák, P. and VanderAuwera, J. and Campargue, A.},
  title = {The ammonia absorption spectrum between 4700 and 5650 cm−1},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2022},
  volume = {292},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2022.108350}
}
DeKreijger S, Schott O, Troian-Gautier L, Cauët E, Hanan GS and Elias B (2022), "Red Absorbing Cyclometalated Ir(III) Diimine Photosensitizers Competent for Hydrogen Photocatalysis", Inorganic Chemistry. Vol. 61(13), pp. 5245 – 5254.
Abstract: Two new cyclometalated Ir(III) diimine complexes were used as photosensitizers for homogeneous hydrogen evolution reaction (HER). These complexes were characterized by electrochemistry, ultraviolet-visible absorption, time-resolved and steady-state photoluminescence spectroscopy as well as by theoretical methods. The metal-ligand-to-ligand charge transfer character of their lowest excited state was shown to be competent for efficient H2photoproduction in the presence of [Co(dmgH)2(py)Cl] as the hydrogen evolution catalyst, triethanolamine as the sacrificial electron donor, and HBF4as the proton source. Under optimized experimental conditions, both complexes displayed HER over a period of more than 90 h, with turnover numbers reaching up to 11,650, 10,600, and 174 molH2molPS-1under blue-, green-, and red-light irradiation, respectively. Both complexes showed higher stability and efficiency vs HER than most of the previously described systems of the same kind. © 2022 American Chemical Society. All rights reserved.
BibTeX:
@article{DeKreijger2022,
  author = {DeKreijger, Simon and Schott, Olivier and Troian-Gautier, Ludovic and Cauët, Emilie and Hanan, Garry S. and Elias, Benjamin},
  title = {Red Absorbing Cyclometalated Ir(III) Diimine Photosensitizers Competent for Hydrogen Photocatalysis},
  journal = {Inorganic Chemistry},
  year = {2022},
  volume = {61},
  number = {13},
  pages = {5245 – 5254},
  doi = {10.1021/acs.inorgchem.1c03727}
}
Demaison J and Liévin J (2022), "Accuracy of the equilibrium structure of sulphur dioxide", Molecular Physics. Vol. 120(15-16)
Abstract: The ground state rotational spectra of 12 different isotopologues of sulphur dioxide have been refitted in a consistent way and an accurate experimental cubic force field has been determined. The experimental, semi-experimental and ab initio equilibrium structures have been calculated and found in good agreement across themselves. Different approximations limiting the accuracy are discussed. In particular, the influence of centrifugal distortion is analysed. A method is proposed to estimate the higher-order rovibrational corrections (γ-constants). Although an accurate semi-experimental structure was obtained for 19 isotopologues, it was not possible to determine and account for the breakdown of the Born–Oppenheimer approximation. Finally, it was shown that the ab initio CCSDTQ level of theory was required to obtain a good agreement with the experimental structure. © 2021 Informa UK Limited, trading as Taylor & Francis Group.
BibTeX:
@article{Demaison2022,
  author = {Demaison, Jean and Liévin, Jacques},
  title = {Accuracy of the equilibrium structure of sulphur dioxide},
  journal = {Molecular Physics},
  year = {2022},
  volume = {120},
  number = {15-16},
  doi = {10.1080/00268976.2021.1950857}
}
Fischer CF and Godefroid M (2022), "Variational Methods for Atoms and the Virial Theorem", Atoms. Vol. 10(4)
Abstract: In the case of the one-electron Dirac equation with a point nucleus, the virial theorem (VT) states that the ratio of the kinetic energy to potential energy is exactly -1, a ratio that can be an independent test of the accuracy of a computed solution. This paper studies the virial theorem for subshells of equivalent electrons and their interactions in many-electron atoms. This shows that the linear scaling of the dilation is achieved through the balancing of the contributions to the potential of an electron from inner and outer regions that some Slater integrals impose conditions on a single subshell, but others impose conditions between subshells. The latter slows the rate of convergence of the self-consistent field process in which radial functions are updated one at a time. Several cases are considered. Results are also extended to the nonrelativistic case. © 2022 by the authors.
BibTeX:
@article{Fischer2022,
  author = {Fischer, Charlotte Froese and Godefroid, Michel},
  title = {Variational Methods for Atoms and the Virial Theorem},
  journal = {Atoms},
  year = {2022},
  volume = {10},
  number = {4},
  note = {All Open Access, Gold Open Access},
  doi = {10.3390/atoms10040110}
}
Fortems-Cheiney A, Dufour G, Foret G, Siour G, VanDamme M, Coheur P-F, Clarisse L, Clerbaux C and Beekmann M (2022), "Understanding the Simulated Ammonia Increasing Trend from 2008 to 2015 over Europe with CHIMERE and Comparison with IASI Observations", Atmosphere. Vol. 13(7)
Abstract: The objective of this study is to assess and understand the NH3 recent trends and to identify the key components driving its concentrations. We have simulated the seasonal cycle, the interannual variability, and the trends in NH3 vertical column densities (VCD) from 2008 to 2015 over Europe, with the CHIMERE regional chemistry–transport model. We have also confronted the simulations against the Infrared Atmospheric Sounding Interferometer (IASI) satellite observations. IASI often shows a strong maximum in summer in addition to the spring peak, whereas CHIMERE only shows a slight peak in summer some years. This result could point to a misrepresentation of the temporal profile of the NH3 emissions, i.e., to missing emission sources during summertime either due to more than expected fertilizer use or to increased volatilization under warmer conditions. The simulated NH3 VCDs present an increasing trend over continental Europe (+2.7 ± 1.0 %/yr) but also at the national scale for Spain, Germany, UK, France, and Poland. Sensitivity tests indicate that these simulated positive trends are mainly due to (i) the trends in NH3 emissions, found heterogeneous in the EMEP NH3 emissions with strong disparities depending on the country, and (ii) the negative trends in NOx and SOx emissions. The impact of reductions in NO2 and SO2 emissions on NH3 concentrations should therefore be taken into account in future policies. This simulated NH3 VCD increase at the European scale is confirmed by IASI-v3R satellite observations in spring and summer, when ammonia emissions strongly contribute to the annual budget in accordance with crop requirements. Nevertheless, there are remaining differences about the significance and magnitude between the simulated and observed trends at the national scale, and it warrants further investigation. © 2022 by the authors.
BibTeX:
@article{FortemsCheiney2022,
  author = {Fortems-Cheiney, Audrey and Dufour, Gaëlle and Foret, Gilles and Siour, Guillaume and VanDamme, Martin and Coheur, Pierre-François and Clarisse, Lieven and Clerbaux, Cathy and Beekmann, Matthias},
  title = {Understanding the Simulated Ammonia Increasing Trend from 2008 to 2015 over Europe with CHIMERE and Comparison with IASI Observations},
  journal = {Atmosphere},
  year = {2022},
  volume = {13},
  number = {7},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atmos13071101}
}
Franco B, Clarisse L, VanDamme M, Hadji-Lazaro J, Clerbaux C and Coheur P-F (2022), "Ethylene industrial emitters seen from space", Nature Communications. Vol. 13(1)
Abstract: Volatile organic compounds are emitted abundantly from a variety of natural and anthropogenic sources. However, in excess, they can severely degrade air quality. Their fluxes are currently poorly represented in inventories due to a lack of constraints from global measurements. Here, we track from space over 300 worldwide hotspots of ethylene, the most abundant industrially produced organic compound. We identify specific emitters associated with petrochemical clusters, steel plants, coal-related industries, and megacities. Satellite-derived fluxes reveal that the ethylene emissions of the industrial sources are underestimated or missing in the state-of-the-art Emission Database for Global Atmospheric Research (EDGAR) inventory. This work exposes global emission point-sources of a short-lived carbonated gas, complementing the ongoing large-scale efforts on the monitoring of inorganic pollutants. © 2022, The Author(s).
BibTeX:
@article{Franco2022,
  author = {Franco, Bruno and Clarisse, Lieven and VanDamme, Martin and Hadji-Lazaro, Juliette and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Ethylene industrial emitters seen from space},
  journal = {Nature Communications},
  year = {2022},
  volume = {13},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1038/s41467-022-34098-8}
}
Gordon I, Rothman L, Hargreaves R, Hashemi R, Karlovets E, Skinner F, Conway E, Hill C, Kochanov R, Tan Y, Wcisło P, Finenko A, Nelson K, Bernath P, Birk M, Boudon V, Campargue A, Chance K, Coustenis A, Drouin B, Flaud J, Gamache R, Hodges J, Jacquemart D, Mlawer E, Nikitin A, Perevalov V, Rotger M, Tennyson J, Toon G, Tran H, Tyuterev V, Adkins E, Baker A, Barbe A, Canè E, Császár A, Dudaryonok A, Egorov O, Fleisher A, Fleurbaey H, Foltynowicz A, Furtenbacher T, Harrison J, Hartmann J, Horneman V, Huang X, Karman T, Karns J, Kassi S, Kleiner I, Kofman V, Kwabia-Tchana F, Lavrentieva N, Lee T, Long D, Lukashevskaya A, Lyulin O, Makhnev V, Matt W, Massie S, Melosso M, Mikhailenko S, Mondelain D, Müller H, Naumenko O, Perrin A, Polyansky O, Raddaoui E, Raston P, Reed Z, Rey M, Richard C, Tóbiás R, Sadiek I, Schwenke D, Starikova E, Sung K, Tamassia F, Tashkun S, VanderAuwera J, Vasilenko I, Vigasin A, Villanueva G, Vispoel B, Wagner G, Yachmenev A and Yurchenko S (2022), "The HITRAN2020 molecular spectroscopic database", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 277
Abstract: The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years). All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replacements of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening parameters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules. The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition. © 2021 The Author(s)
BibTeX:
@article{Gordon2022,
  author = {Gordon, I.E. and Rothman, L.S. and Hargreaves, R.J. and Hashemi, R. and Karlovets, E.V. and Skinner, F.M. and Conway, E.K. and Hill, C. and Kochanov, R.V. and Tan, Y. and Wcisło, P. and Finenko, A.A. and Nelson, K. and Bernath, P.F. and Birk, M. and Boudon, V. and Campargue, A. and Chance, K.V. and Coustenis, A. and Drouin, B.J. and Flaud, J.M. and Gamache, R.R. and Hodges, J.T. and Jacquemart, D. and Mlawer, E.J. and Nikitin, A.V. and Perevalov, V.I. and Rotger, M. and Tennyson, J. and Toon, G.C. and Tran, H. and Tyuterev, V.G. and Adkins, E.M. and Baker, A. and Barbe, A. and Canè, E. and Császár, A.G. and Dudaryonok, A. and Egorov, O. and Fleisher, A.J. and Fleurbaey, H. and Foltynowicz, A. and Furtenbacher, T. and Harrison, J.J. and Hartmann, J.M. and Horneman, V.M. and Huang, X. and Karman, T. and Karns, J. and Kassi, S. and Kleiner, I. and Kofman, V. and Kwabia-Tchana, F. and Lavrentieva, N.N. and Lee, T.J. and Long, D.A. and Lukashevskaya, A.A. and Lyulin, O.M. and Makhnev, V.Yu. and Matt, W. and Massie, S.T. and Melosso, M. and Mikhailenko, S.N. and Mondelain, D. and Müller, H.S.P. and Naumenko, O.V. and Perrin, A. and Polyansky, O.L. and Raddaoui, E. and Raston, P.L. and Reed, Z.D. and Rey, M. and Richard, C. and Tóbiás, R. and Sadiek, I. and Schwenke, D.W. and Starikova, E. and Sung, K. and Tamassia, F. and Tashkun, S.A. and VanderAuwera, J. and Vasilenko, I.A. and Vigasin, A.A. and Villanueva, G.L. and Vispoel, B. and Wagner, G. and Yachmenev, A. and Yurchenko, S.N.},
  title = {The HITRAN2020 molecular spectroscopic database},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2022},
  volume = {277},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.jqsrt.2021.107949}
}
Herrera B, Bezanilla A, Blumenstock T, Dammers E, Hase F, Clarisse L, Magaldi A, Rivera C, Stremme W, Strong K, Viatte C, VanDamme M and Grutter M (2022), "Measurement report: Evolution and distribution of NH3over Mexico City from ground-based and satellite infrared spectroscopic measurements", Atmospheric Chemistry and Physics. Vol. 22(21), pp. 14119 – 14132.
Abstract: Ammonia (NH3) is the most abundant alkaline compound in the atmosphere, with consequences for the environment, human health, and radiative forcing. In urban environments, it is known to play a key role in the formation of secondary aerosols through its reactions with nitric and sulfuric acids. However, there are only a few studies about NH3 in Mexico City. In this work, atmospheric NH3 was measured over Mexico City between 2012 and 2020 by means of ground-based solar absorption spectroscopy using Fourier transform infrared (FTIR) spectrometers at two sites (urban and remote). Total columns of NH3 were retrieved from the FTIR spectra and compared with data obtained from the Infrared Atmospheric Sounding Interferometer (IASI) satellite instrument. The diurnal variability of NH3 differs between the two FTIR stations and is strongly influenced by the urban sources. Most of the NH3 measured at the urban station is from local sources, while the NH3 observed at the remote site is most likely transported from the city and surrounding areas. The evolution of the boundary layer and the temperature play a significant role in the recorded seasonal and diurnal patterns of NH3. Although the vertical columns of NH3 are much larger at the urban station, the observed annual cycles are similar for both stations, with the largest values in the warm months, such as April and May. The IASI measurements underestimate the FTIR NH3 total columns by an average of 32.2±27.5 % but exhibit similar temporal variability. The NH3 spatial distribution from IASI shows the largest columns in the northeast part of the city. In general, NH3 total columns over Mexico City measured at the FTIR stations exhibited an average annual increase of 92±3.9×1013 molecules cm-2 yr-1 (urban, from 2012 to 2019) and 8.4±1.4×1013 molecules cm-2 yr-1 (remote, from 2012 to 2020), while IASI data within 20 km of the urban station exhibited an average annual increase of 38±7.6×1013 molecules cm-2 yr-1 from 2008 to 2018. Copyright © 2022 Beatriz Herrera et al.
BibTeX:
@article{Herrera2022,
  author = {Herrera, Beatriz and Bezanilla, Alejandro and Blumenstock, Thomas and Dammers, Enrico and Hase, Frank and Clarisse, Lieven and Magaldi, Adolfo and Rivera, Claudia and Stremme, Wolfgang and Strong, Kimberly and Viatte, Camille and VanDamme, Martin and Grutter, Michel},
  title = {Measurement report: Evolution and distribution of NH3over Mexico City from ground-based and satellite infrared spectroscopic measurements},
  journal = {Atmospheric Chemistry and Physics},
  year = {2022},
  volume = {22},
  number = {21},
  pages = {14119 – 14132},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-22-14119-2022}
}
Koukouli M-E, Michailidis K, Hedelt P, Taylor IA, Inness A, Clarisse L, Balis D, Efremenko D, Loyola D, Grainger RG and Retscher C (2022), "Volcanic SO2layer height by TROPOMI/S5P: evaluation against IASI/MetOp and CALIOP/CALIPSO observations", Atmospheric Chemistry and Physics. Vol. 22(8), pp. 5665 – 5683.
Abstract: Volcanic eruptions eject large amounts of ash and trace gases such as sulfur dioxide (SO2) into the atmosphere. A significant difficulty in mitigating the impact of volcanic SO2 clouds on air traffic safety is that these gas emissions can be rapidly transported over long distances. The use of space-borne instruments enables the global monitoring of volcanic SO2 emissions in an economical and risk-free manner. Within the European Space Agency (ESA) Sentinel-5p+ Innovation project, the S5P SO2 layer height (S5P+I: SO2LH) activities led to the improvements of the retrieval algorithm and generation of the corresponding near real-time S5P SO2 LH products. These are currently operationally provided, in near real-time, by the German Aerospace Center (DLR) within the framework of the Innovative Products for Analyses of Atmospheric Composition (INPULS) project. The main aim of this paper is to present its extensive verification, accomplished within the S5P+I: SO2LH project, over major recent volcanic eruptions, against collocated space-borne measurements from the IASI/Metop and CALIOP/CALIPSO instruments as well as assess its impact on the forecasts provided by the Copernicus Atmospheric Monitoring Service (CAMS). The mean difference between S5P and IASI observations for the Raikoke 2019, the Nishinoshima 2020 and the La Soufrière-St Vincent 2021 eruptive periods is g-1/4 0.5 ± 3 km, while for the Taal 2020 eruption, a larger difference was found, between 3 ± 3 km and 4 ± 3 km. The comparison of the daily mean SO2 LH further demonstrates the capabilities of this near real-time product, with slopes between 0.8 and 1 and correlation coefficients ranging between 0.6 and 0.8. Comparisons between the S5P SO2 LH and the CALIOP/CALIPSO ash plumes revealed an expected bias at -2.5 ± 2 km, considering that the injected SO2 and ash plume locations do not always coincide over an eruption. Furthermore, the CAMS assimilation of the S5P SO2 LH product led to much improved model output against the non-assimilated IASI LH, with a mean difference of 1.5 ± 2 km, compared to the original CAMS analysis, and improved the geographical spread of the Raikoke volcanic plume following the eruptive days. © 2022 Maria-Elissavet Koukouli et al.
BibTeX:
@article{Koukouli2022,
  author = {Koukouli, Maria-Elissavet and Michailidis, Konstantinos and Hedelt, Pascal and Taylor, Isabelle A. and Inness, Antje and Clarisse, Lieven and Balis, Dimitris and Efremenko, Dmitry and Loyola, Diego and Grainger, Roy G. and Retscher, Christian},
  title = {Volcanic SO2layer height by TROPOMI/S5P: evaluation against IASI/MetOp and CALIOP/CALIPSO observations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2022},
  volume = {22},
  number = {8},
  pages = {5665 – 5683},
  doi = {10.5194/acp-22-5665-2022}
}
Li J, Gaigalas G, Bieroń J, Ekman J, Jönsson P, Godefroid M and FroeseFischer C (2022), "Re-Evaluation of the Nuclear Magnetic Octupole Moment of 209Bi", Atoms. Vol. 10(4)
Abstract: We modified the Hfs92 code of the GRASP package in order to describe the magnetic octupole hyperfine interaction. To illustrate the utility of the modified code, we carried out state-of-the-art calculations of the electronic factors of the magnetic octupole hyperfine interaction constants for levels in the ground configuration of the Bi atom. The nuclear magnetic octupole moment of the (Formula presented.) Bi isotope was extracted by combining old measurements of the hyperfine structures of (Formula presented.) [Hull, R.; Brink, G. Phys. Rev. A 1970, 1, 685] and (Formula presented.) [Landman, D.A.; Lurio, A. Phys. Rev. A 1970, 1, 1330] using the atomic-beam magnetic-resonance technique with our theoretical electronic factors. The present extracted octupole moment was consistent with all the available values but the one obtained in the single-particle nuclear shell model approximation. This observation supports the previous finding that nuclear many-body effects, such as the core polarization, significantly contribute to the nuclear magnetic octupole moment in the case of (Formula presented.) Bi. © 2022 by the authors.
BibTeX:
@article{Li2022a,
  author = {Li, Jiguang and Gaigalas, Gediminas and Bieroń, Jacek and Ekman, Jörgen and Jönsson, Per and Godefroid, Michel and FroeseFischer, Charlotte},
  title = {Re-Evaluation of the Nuclear Magnetic Octupole Moment of 209Bi},
  journal = {Atoms},
  year = {2022},
  volume = {10},
  number = {4},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atoms10040132}
}
Li J, Zhang C, Del Zanna G, Jönsson P, Godefroid M, Gaigalas G, Rynkun P, Radziūte L, Wang K, Si R and Chen C (2022), "Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: C-like Ions from O iii to Mg vii", Astrophysical Journal, Supplement Series. Vol. 260(2)
Abstract: Large-scale multiconfiguration Dirac-Hartree-Fock calculations are provided for the n ≤ 5 states in C-like ions from O iii to Mg vii. Electron correlation effects are accounted for by using large configuration state function expansions, built from sets of orbitals with principal quantum numbers n ≤ 10. An accurate and complete data set of excitation energies, wavelengths, radiative transition parameters, and lifetimes is offered for the 156 (196, 215, 272, 318) lowest states of the 2s 22p 2, 2s2p 3, 2p 4, 2s 22p3s, 2s 22p3p, 2s 22p3d, 2s2p 23s, 2s2p 23p, 2s2p 23d, 2p 33s, 2p 33p, 2p 33d, 2s 22p4s, 2s 22p4p, 2s 22p4d, 2s 22p4f, 2s2p 24s, 2s2p 24p, 2s2p 24d, 2s2p 24f, 2s 22p5s, 2s 22p5p, 2s 22p5d, 2s 22p5f, and 2s 22p5g configurations in O iii (F iv, Ne v, Na vi, Mg vii). By comparing available experimental wavelengths with the MCDHF results, the previous line identifications for the n = 5, 4, 3 → n = 2 transitions of Na vi in the X-ray and EUV wavelength range are revised. For several previous identifications discrepancies are found, and tentative new (or revised) identifications are proposed. A consistent atomic data set including both energy and transition data with spectroscopic accuracy is provided for the lowest hundreds of states for C-like ions from O iii to Mg vii. © 2022. The Author(s). Published by the American Astronomical Society.
BibTeX:
@article{Li2022,
  author = {Li, J.Q. and Zhang, C.Y. and Del Zanna, G. and Jönsson, P. and Godefroid, M. and Gaigalas, G. and Rynkun, P. and Radziūte, L. and Wang, K. and Si, R. and Chen, C.Y.},
  title = {Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: C-like Ions from O iii to Mg vii},
  journal = {Astrophysical Journal, Supplement Series},
  year = {2022},
  volume = {260},
  number = {2},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3847/1538-4365/ac63ae}
}
Luo Z, Zhang Y, Chen W, VanDamme M, Coheur P-F and Clarisse L (2022), "Estimating global ammonia (NH3) emissions based on IASI observations from 2008 to 2018", Atmospheric Chemistry and Physics. Vol. 22(15), pp. 10375 – 10388.
Abstract: Emissions of ammonia (NH3) to the atmosphere impact human health, climate, and ecosystems via their critical contributions to secondary aerosol formation. However, the estimation of NH3 emissions is associated with large uncertainties because of inadequate knowledge about agricultural sources. Here, we use satellite observations from the Infrared Atmospheric Sounding Interferometer (IASI) and simulations from the GEOS-Chem model to constrain global NH3 emissions over the period from 2008 to 2018. We update the prior NH3 emission fluxes with the ratio between biases in simulated NH3 concentrations and effective NH3 lifetimes against the loss of the NHx family. In contrast to the approximate factor of 2 discrepancies between top-down and bottom-up emissions found in previous studies, our method results in a global land NH3 emission of 78 (70-92)g Tgg a-1, which is g 1/430g % higher than the bottom-up estimates. Regionally, we find that the bottom-up inventory underestimates NH3 emissions over South America and tropical Africa by 60g %-70g %, indicating underrepresentation of agricultural sources in these regions. We find a good agreement within 10g % between bottom-up and top-down estimates over the US, Europe, and eastern China. Our results also show significant increases in NH3 emissions over India (13g % per decade), tropical Africa (33g % per decade), and South America (18g % per decade) during our study period, which is consistent with the intensifying agricultural activity in these regions in the past decade. We find that the inclusion of the sulfur dioxide (SO2) column observed by satellite is crucial for more accurate inference of NH3 emission trends over important source regions such as India and China where SO2 emissions have changed rapidly in recent years. © 2022 Copernicus GmbH. All rights reserved.
BibTeX:
@article{Luo2022,
  author = {Luo, Zhenqi and Zhang, Yuzhong and Chen, Wei and VanDamme, Martin and Coheur, Pierre-François and Clarisse, Lieven},
  title = {Estimating global ammonia (NH3) emissions based on IASI observations from 2008 to 2018},
  journal = {Atmospheric Chemistry and Physics},
  year = {2022},
  volume = {22},
  number = {15},
  pages = {10375 – 10388},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-22-10375-2022}
}
Pan LL, Kinnison D, Liang Q, Chin M, Santee ML, Flemming J, Smith WP, Honomichl SB, Bresch JF, Lait LR, Zhu Y, Tilmes S, Colarco PR, Warner J, Vuvan A, Clerbaux C, Atlas EL, Newman PA, Thornberry T, Randel WJ and Toon OB (2022), "A Multimodel Investigation of Asian Summer Monsoon UTLS Transport Over the Western Pacific", Journal of Geophysical Research: Atmospheres. Vol. 127(24)
Abstract: The Asian summer monsoon (ASM) as a chemical transport system is investigated using a suite of models in preparation for an airborne field campaign over the Western Pacific. Results show that the dynamical process of anticyclone eddy shedding in the upper troposphere rapidly transports convectively uplifted Asian boundary layer air masses to the upper troposphere and lower stratosphere over the Western Pacific. The models show that the transported air masses contain significantly enhanced aerosol loading and a complex chemical mixture of trace gases that are relevant to ozone chemistry. The chemical forecast models consistently predict the occurrence of the shedding events, but the predicted concentrations of transported trace gases and aerosols often differ between models. The airborne measurements to be obtained in the field campaign are expected to help reduce the model uncertainties. Furthermore, the large-scale seasonal chemical structure of the monsoon system is obtained from modeled carbon monoxide, a tracer of the convective transport of pollutants, which provides a new perspective of the ASM circulation, complementing the dynamical characterization of the monsoon. © 2022. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Pan2022,
  author = {Pan, Laura L. and Kinnison, Douglas and Liang, Qing and Chin, Mian and Santee, Michelle L. and Flemming, Johannes and Smith, Warren P. and Honomichl, Shawn B. and Bresch, James F. and Lait, Leslie R. and Zhu, Yunqian and Tilmes, Simone and Colarco, Peter R. and Warner, Juying and Vuvan, Adrien and Clerbaux, Cathy and Atlas, Elliot L. and Newman, Paul A. and Thornberry, Troy and Randel, William J. and Toon, Owen B.},
  title = {A Multimodel Investigation of Asian Summer Monsoon UTLS Transport Over the Western Pacific},
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2022},
  volume = {127},
  number = {24},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2022JD037511}
}
Pozzer A, Reifenberg SF, Kumar V, Franco B, Kohl M, Taraborrelli D, Gromov S, Ehrhart S, Jöckel P, Sander R, Fall V, Rosanka S, Karydis V, Akritidis D, Emmerichs T, Crippa M, Guizzardi D, Kaiser JW, Clarisse L, Kiendler-Scharr A, Tost H and Tsimpidi A (2022), "Simulation of organics in the atmosphere: evaluation of EMACv2.54 with the Mainz Organic Mechanism (MOM) coupled to the ORACLE (v1.0) submodel", Geoscientific Model Development. Vol. 15(6), pp. 2673 – 2710.
Abstract: An updated and expanded representation of organics in the chemistry general circulation model EMAC (ECHAM5/MESSy for Atmospheric Chemistry) has been evaluated. First, the comprehensive Mainz Organic Mechanism (MOM) in the submodel MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) was activated with explicit degradation of organic species up to five carbon atoms and a simplified mechanism for larger molecules. Second, the ORACLE submodel (version 1.0) now considers condensation on aerosols for all organics in the mechanism. Parameterizations for aerosol yields are used only for the lumped species that are not included in the explicit mechanism. The simultaneous usage of MOM and ORACLE allows an efficient estimation of not only the chemical degradation of the simulated volatile organic compounds but also the contribution of organics to the growth and fate of (organic) aerosol, with the complexity of the mechanism largely increased compared to EMAC simulations with more simplified chemistry. The model evaluation presented here reveals that the OH concentration is reproduced well globally, whereas significant biases for observed oxygenated organics are present. We also investigate the general properties of the aerosols and their composition, showing that the more sophisticated and process-oriented secondary aerosol formation does not degrade the good agreement of previous model configurations with observations at the surface, allowing further research in the field of gas-aerosol interactions. Copyright: © 2022 Andrea Pozzer et al.
BibTeX:
@article{Pozzer2022,
  author = {Pozzer, Andrea and Reifenberg, Simon F. and Kumar, Vinod and Franco, Bruno and Kohl, Matthias and Taraborrelli, Domenico and Gromov, Sergey and Ehrhart, Sebastian and Jöckel, Patrick and Sander, Rolf and Fall, Veronica and Rosanka, Simon and Karydis, Vlassis and Akritidis, Dimitris and Emmerichs, Tamara and Crippa, Monica and Guizzardi, Diego and Kaiser, Johannes W. and Clarisse, Lieven and Kiendler-Scharr, Astrid and Tost, Holger and Tsimpidi, Alexandra},
  title = {Simulation of organics in the atmosphere: evaluation of EMACv2.54 with the Mainz Organic Mechanism (MOM) coupled to the ORACLE (v1.0) submodel},
  journal = {Geoscientific Model Development},
  year = {2022},
  volume = {15},
  number = {6},
  pages = {2673 – 2710},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/gmd-15-2673-2022}
}
Safieddine S, Clerbaux C, Clarisse L, Whitburn S and Eltahir E (2022), "Present and future land surface and wet bulb temperatures in the Arabian Peninsula", Environmental Research Letters. Vol. 17(4)
Abstract: The Arabian Peninsula exhibits extreme hot summers and has one of the world's largest population growths. We use satellite observations and reanalysis as well as climate model projections to analyze morning and evening land surface temperatures (LSTs), to refer to processes at the surface, and wet bulb temperatures (WBTs) to measure human heat stress. We focus on three regions: the Persian Gulf and Gulf of Oman, the inland capital of Saudi Arabia, Riyadh and the irrigated agricultural region in Al-Jouf, Saudi Arabia. This study shows that the time of day is important when studying LST and WBT, with current and future WBT higher in the early summer evenings. It also shows that the effect of humidity brought from waterbodies or through irrigation can significantly increase heat stress. Over the coasts of the Peninsula, humidity decreases LST but increases heat stress via WBT values higher than 25 °C in the evening. Riyadh, located in the heart of the Peninsula has lower WBT of 15 °C-17.5 °C and LST reaching 42.5 °C. Irrigation in the Al-Jouf province decreases LST by up to 10° with respect to its surroundings, while it increases WBT by up to 2.5°. Climate projections over the Arabian Peninsula suggest that global efforts will determine the survivability in this region. The projected increase in LST and WBT are +6 °C and +4 °C, respectively, in the Persian Gulf and Riyadh by the end of the century, posing significant risks on human survivability in the Peninsula unless strict climate mitigation takes place. © 2022 The Author(s). Published by IOP Publishing Ltd.
BibTeX:
@article{Safieddine2022,
  author = {Safieddine, S. and Clerbaux, C. and Clarisse, L. and Whitburn, S. and Eltahir, E.A.B.},
  title = {Present and future land surface and wet bulb temperatures in the Arabian Peninsula},
  journal = {Environmental Research Letters},
  year = {2022},
  volume = {17},
  number = {4},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1088/1748-9326/ac507c}
}
Schiffmann S, Li J, Ekman J, Gaigalas G, Godefroid M, Jönsson P and Bieroń J (2022), "Relativistic radial electron density functions and natural orbitals from GRASP2018", Computer Physics Communications. Vol. 278
Abstract: A new module, RDENSITY, of the GRASP2018 package [1] is presented for evaluating the radial electron density function of an atomic state described by a multiconfiguration Dirac-Hartree-Fock or configuration interaction wave function in the fully relativistic scheme. The present module is the relativistic version of DENSITY [2] that was developed for the ATSP2K package [3]. The calculation of the spin-angular factors entering in the expression of the expectation value of the density operator is performed using the angular momentum theory in orbital, spin, and quasispin spaces, adopting a generalized graphical technique [4]. The natural orbitals (NOs) are evaluated from the diagonalization of the density matrix, taking advantage of its κ-block structure. The features of the code are discussed in detail, focusing on the advantages and properties of the NOs and on the electron radial density picture as a mean for investigating electron correlation and relativistic effects. Program summary: Program title: RDENSITY CPC Library link to program files: https://doi.org/10.17632/4sdrf5kfzd.1 Licensing provisions: MIT license Programming language: FORTRAN 95 Nature of problem: This program determines the atomic electron radial density in the MCDHF approximation. It also evaluates the natural orbitals by diagonalizing the density matrix. Solution method: Building the density operator using second quantization - Spherical symmetry averaging - Evaluating the matrix elements of the one-body excitation operators in the configuration state function (CSF) space using the angular momentum theory in orbital, spin, and quasispin spaces. Additional comments including restrictions and unusual features: We evaluated the electron radial density and natural orbitals of the lowest states in Mg II. The MCDHF wave functions consisted of four non-interacting blocks and a total of 79 000 CSFs. The calculation took around 2 minutes using a computer with an Intel(R) Xeon(R) Gold 6148 processor @ 2.4 GHz. References: [1] GRASP2018 - A Fortran 95 version of the General Relativistic Atomic Structure Package, C. FroeseFischer, G. Gaigalas, P. Jönsson and J. Bieroń, Comput. Phys. Commun. 237 (2019) 184-187. [2] Multiconfiguration electron density function for the ATSP2K-package, A. Borgoo, O. Scharf, G. Gaigalas and M. Godefroid, Comput. Phys. Commun. 181 (2010) 426-439 [3] An MCHF atomic-structure package for large-scale calculations, C. FroeseFischer, G. Tachiev, G. Gaigalas, and M. Godefroid, Comput. Phys. Commun. 176 (2007) 559-579 [4] An efficient approach for spin-angular integrations in atomic structure calculations, G. Gaigalas, Z. Rudzikas, and C. FroeseFischer, J. Phys. B: At. Mol. Phys., 30 (1997) 3747-3771 © 2022
BibTeX:
@article{Schiffmann2022,
  author = {Schiffmann, S. and Li, J.G. and Ekman, J. and Gaigalas, G. and Godefroid, M. and Jönsson, P. and Bieroń, J.},
  title = {Relativistic radial electron density functions and natural orbitals from GRASP2018},
  journal = {Computer Physics Communications},
  year = {2022},
  volume = {278},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.cpc.2022.108403}
}
Sutcliffe B and Woolley RG (2022), "Is Chemistry Really Founded in Quantum Mechanics?", Synthese Library. Vol. 461, pp. 173 – 202.
Abstract: The solutions of the Schrödinger Coulomb Hamiltonian, in which the nuclei are fixed and identified, are discussed as providing a theoretical foundation for chemistry. It is shown that supportive relevant aspects of these clamped-nuclei solutions do not arise in solutions of the full problem; further, it is not, at present, possible to regard the clamped-nuclei Hamiltonian as an approximation to the full Hamiltonian. © 2022, Springer Nature Switzerland AG.
BibTeX:
@article{Sutcliffe2022,
  author = {Sutcliffe, Brian and Woolley, R. Guy},
  title = {Is Chemistry Really Founded in Quantum Mechanics?},
  journal = {Synthese Library},
  year = {2022},
  volume = {461},
  pages = {173 – 202},
  note = {All Open Access, Green Open Access},
  doi = {10.1007/978-3-030-98373-4_8}
}
Theys N, Lerot C, Brenot H, VanGent J, De Smedt I, Clarisse L, Burton M, Varnam M, Hayer C, Esse B and vanRoozendael M (2022), "Improved retrieval of SO2 plume height from TROPOMI using an iterative Covariance-Based Retrieval Algorithm", Atmospheric Measurement Techniques. Vol. 15(16), pp. 4801 – 4817.
Abstract: Knowledge of sulfur dioxide layer height (SO2 LH) is important to understand volcanic eruption processes, the climate impact of SO2 emissions and to mitigate volcanic risk for civil aviation. However, the estimation of SO2 LH from ground-based instruments is challenging in particular for rapidly evolving and sustained eruptions. Satellite wide-swath nadir observations have the advantage to cover large-scale plumes and the potential to provide key information on SO2 LH. In the ultraviolet, SO2 LH retrievals leverage the fact that, for large SO2 columns, the light path and its associated air mass factor (AMF) depends on the SO2 absorption (and therefore on the vertical distribution of SO2), and SO2 LH information can be obtained from the analysis of measured back-scattered radiances coupled with radiative transfer simulations. However, existing algorithms are mainly sensitive to SO2 LH for SO2 vertical columns of at least 20 DU. Here we develop a new SO2 LH algorithm and apply it to observations from the high-spatial-resolution TROPOspheric Monitoring Instrument (TROPOMI). It is based on an SO2 optical depth look-up table and an iterative approach. The strength of this scheme lies in the fact that it is a Covariance-Based Retrieval Algorithm (COBRA; Theys et al., 2021). This means that the SO2-free contribution of the measured optical depth is treated in an optimal way, resulting in an improvement of the SO2 LH sensitivity to SO2 columns as low as 5 DU, with a precision better than 2 km. We demonstrate the value of this new data through a number of examples and comparison with satellite plume height estimates (from IASI and CALIOP), and back-trajectory analyses. The comparisons indicate an SO2 LH accuracy of 1–2 km, except for some difficult observation conditions, in particular for optically thick ash plumes or partially SO2-filled scenes. © Author(s) 2022.
BibTeX:
@article{Theys2022,
  author = {Theys, Nicolas and Lerot, Christophe and Brenot, Hugues and VanGent, Jeroen and De Smedt, Isabelle and Clarisse, Lieven and Burton, Mike and Varnam, Matthew and Hayer, Catherine and Esse, Benjamin and vanRoozendael, Michel},
  title = {Improved retrieval of SO2 plume height from TROPOMI using an iterative Covariance-Based Retrieval Algorithm},
  journal = {Atmospheric Measurement Techniques},
  year = {2022},
  volume = {15},
  number = {16},
  pages = {4801 – 4817},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-15-4801-2022}
}
Tidiga M, Berthet G, Jégou F, Kloss C, Bègue N, Vernier J-P, Renard J-B, Bossolasco A, Clarisse L, Taha G, Portafaix T, Deshler T, Wienhold FG, Godin-Beekmann S, Payen G, Metzger J-M, Duflot V and Marquestaut N (2022), "Variability of the Aerosol Content in the Tropical Lower Stratosphere from 2013 to 2019: Evidence of Volcanic Eruption Impacts", Atmosphere. Vol. 13(2)
Abstract: This paper quantifies the tropical stratospheric aerosol content as impacted by volcanic events over the 2013–2019 period. We use global model simulations by the Whole Atmosphere Community Climate Model (WACCM) which is part of the Community Earth System Model version 1.0 (CESM1). WACCM is associated with the Community Aerosol and Radiation Model for Atmospheres (CARMA) sectional aerosol microphysics model which includes full sulphur chemical and microphysical cycles with no a priori assumption on particle size. Five main volcanic events (Kelud, Calbuco, Ambae, Raikoke and Ulawun) have been reported and are shown to have significantly influenced the stratospheric aerosol layer in the tropics, either through direct injection in this region or through transport from extra-tropical latitudes. Space-borne data as well as ground-based lidar and balloon-borne in situ observations are used to evaluate the model calculations in terms of aerosol content, vertical distribution, optical and microphysical properties, transport and residence time of the various volcanic plumes. Overall, zonal mean model results reproduce the occurrence and vertical extents of the plumes derived from satellite observations but shows some discrepancies for absolute values of extinction and of stratospheric aerosol optical depth (SAOD). Features of meridional transport of the plumes emitted from extra-tropical latitudes are captured by the model but simulated absolute values of SAOD differ from 6 to 200% among the various eruptions. Simulations tend to agree well with observed in situ vertical profiles for the Kelud and Calbuco plumes but this is likely to depend on the period for which comparison is done. Some explanations for the model– measurement discrepancies are discussed such as the inaccurate knowledge of the injection parameters and the presence of ash not accounted in the simulations. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Tidiga2022,
  author = {Tidiga, Mariam and Berthet, Gwenaël and Jégou, Fabrice and Kloss, Corinna and Bègue, Nelson and Vernier, Jean-Paul and Renard, Jean-Baptiste and Bossolasco, Adriana and Clarisse, Lieven and Taha, Ghassan and Portafaix, Thierry and Deshler, Terry and Wienhold, Frank G. and Godin-Beekmann, Sophie and Payen, Guillaume and Metzger, Jean-Marc and Duflot, Valentin and Marquestaut, Nicolas},
  title = {Variability of the Aerosol Content in the Tropical Lower Stratosphere from 2013 to 2019: Evidence of Volcanic Eruption Impacts},
  journal = {Atmosphere},
  year = {2022},
  volume = {13},
  number = {2},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atmos13020250}
}
VanDamme M, Clarisse L, Stavrakou T, Wichink Kruit R, Sellekaerts L, Viatte C, Clerbaux C and Coheur P-F (2022), "On the weekly cycle of atmospheric ammonia over European agricultural hotspots", Scientific Reports. Vol. 12(1)
Abstract: The presence of a weekly cycle in the abundance of an atmospheric constituent is a typical fingerprint for the anthropogenic nature of its emission sources. However, while ammonia is mainly emitted as a consequence of human activities, a weekly cycle has never been detected in its abundances at large scale. We expose here for the first time the presence of a weekend effect in the NH3 total columns measured by the IASI satellite sounder over the main agricultural source regions in Europe: northwestern Europe (Belgium-the Netherlands-northwest Germany), the Po Valley, Brittany, and, to a lesser extent, the Ebro Valley. A decrease of 15% relative to the weekly mean is seen on Sunday–Monday observations in northwestern Europe, as a result of reduced NH3 emissions over the weekend. This is confirmed by in situ NH3 concentration data from the National Air Quality Monitoring Network in the Netherlands, where an average reduction of 10% is found around midnight on Sunday. The identified weekend effect presents a strong seasonal variability, with two peaks, one in spring and one in summer, coinciding with the two main (manure) fertilization periods. In spring, a reduction on Sunday–Monday up to 53 and 26% is found in the NH3 satellite columns and in situ concentrations, respectively, as fertilization largely drives atmospheric NH3 abundances at this time of the year. © 2022, The Author(s).
BibTeX:
@article{VanDamme2022,
  author = {VanDamme, Martin and Clarisse, Lieven and Stavrakou, Trissevgeni and Wichink Kruit, Roy and Sellekaerts, Louise and Viatte, Camille and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {On the weekly cycle of atmospheric ammonia over European agricultural hotspots},
  journal = {Scientific Reports},
  year = {2022},
  volume = {12},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1038/s41598-022-15836-w}
}
Viatte C, Abeed R, Yamanouchi S, Porter WC, Safieddine S, VanDamme M, Clarisse L, Herrera B, Grutter M, Coheur P-F, Strong K and Clerbaux C (2022), "NH3 spatiotemporal variability over Paris, Mexico City, and Toronto, and its link to PM2.5 during pollution events", Atmospheric Chemistry and Physics. Vol. 22(19), pp. 12907 – 12922.
Abstract: Megacities can experience high levels of fine particulate matter (PM2.5) pollution linked to ammonia (NH3) mainly emitted from agricultural activities. Here, we investigate such pollution in the cities of Paris, Mexico, and Toronto, each of which have distinct emission sources, agricultural regulations, and topography. Ten years of measurements from the infrared atmospheric sounding interferometer (IASI) are used to assess the spatiotemporal NH3 variability over and around the three cities. In Europe and North America, we determine that temperature is associated with the increase in NH3 atmospheric concentrations with a coefficient of determination (r2) of 0.8 over agricultural areas. The variety of the NH3 sources (industry and agricultural) and the weaker temperature seasonal cycle in southern North America induce a lower correlation factor (r2Combining double low line0.5). The three regions are subject to long-range transport of NH3, as shown using HYSPLIT cluster back trajectories. The highest NH3 concentrations measured at the city scale are associated with air masses coming from the surrounding and north/northeast regions of Paris, the south/southwest areas of Toronto, and the southeast/southwest zones of Mexico City. Using NH3 and PM2.5 measurements derived from IASI and surface observations from 2008 to 2017, annually frequent pollution events are identified in the three cities. Wind roses reveal statistical patterns during these pollution events with dominant northeast/southwest directions in Paris and Mexico City, and the transboundary transport of pollutants from the United States in Toronto. To check how well chemistry transport models perform during pollution events, we evaluate simulations made using the GEOS-Chem model for March 2011. In these simulations we find that NH3 concentrations are underestimated overall, though day-to-day variability is well represented. PM2.5 is generally underestimated over Paris and Mexico City, but overestimated over Toronto. © Author(s) 2022.
BibTeX:
@article{Viatte2022,
  author = {Viatte, Camille and Abeed, Rimal and Yamanouchi, Shoma and Porter, William C. and Safieddine, Sarah and VanDamme, Martin and Clarisse, Lieven and Herrera, Beatriz and Grutter, Michel and Coheur, Pierre-Francois and Strong, Kimberly and Clerbaux, Cathy},
  title = {NH3 spatiotemporal variability over Paris, Mexico City, and Toronto, and its link to PM2.5 during pollution events},
  journal = {Atmospheric Chemistry and Physics},
  year = {2022},
  volume = {22},
  number = {19},
  pages = {12907 – 12922},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-22-12907-2022}
}
Vohra K, Marais EA, Bloss WJ, Schwartz J, Mickley LJ, VanDamme M, Clarisse L and Coheur P-F (2022), "Rapid rise in premature mortality due to anthropogenic air pollution in fast-growing tropical cities from 2005 to 2018", Science Advances. Vol. 8(14)
Abstract: Tropical cities are experiencing rapid growth but lack routine air pollution monitoring to develop prescient air quality policies. Here, we conduct targeted sampling of recent (2000s to 2010s) observations of air pollutants from space-based instruments over 46 fast-growing tropical cities. We quantify significant annual increases in nitrogen dioxide (NO2) (1 to 14%), ammonia (2 to 12%), and reactive volatile organic compounds (1 to 11%) in most cities, driven almost exclusively by emerging anthropogenic sources rather than traditional biomass burning. We estimate annual increases in urban population exposure to air pollutants of 1 to 18% for fine particles (PM2.5) and 2 to 23% for NO2 from 2005 to 2018 and attribute 180,000 (95% confidence interval: -230,000 to 590,000) additional premature deaths in 2018 (62% increase relative to 2005) to this increase in exposure. These cities are predicted to reach populations of up to 80 million people by 2100, so regulatory action targeting emerging anthropogenic sources is urgently needed. © 2022 The Authors.
BibTeX:
@article{Vohra2022,
  author = {Vohra, Karn and Marais, Eloise A. and Bloss, William J. and Schwartz, Joel and Mickley, Loretta J. and VanDamme, Martin and Clarisse, Lieven and Coheur, Pierre-F.},
  title = {Rapid rise in premature mortality due to anthropogenic air pollution in fast-growing tropical cities from 2005 to 2018},
  journal = {Science Advances},
  year = {2022},
  volume = {8},
  number = {14},
  note = {All Open Access, Green Open Access},
  doi = {10.1126/sciadv.abm4435}
}
Wang W, Liu C, Clarisse L, VanDamme M, Coheur P-F, Xie Y, Shan C, Hu Q, Sun Y and Jones N (2022), "Ground-based measurements of atmospheric NH3 by Fourier transform infrared spectrometry at Hefei and comparisons with IASI data", Atmospheric Environment. Vol. 287
Abstract: Atmospheric ammonia (NH3) plays an important role in the formation of fine particulate matter, leading to severe environmental degradation and human health issues. In this work, ground-based Fourier transform infrared spectrometry (FTIR) observations are used to obtain the total columns of atmospheric NH3 at Hefei, China, from December 2016 to December 2020. After the presentation of the retrieval algorithm and uncertainty budget, we perform a spatio-temporal analysis of the dataset. Over the four years, NH3 columns have been increasing by 15.82% (2017–2018), 3.83% (2018–2019) and 3.68% (2019–2020). A clear seasonal cycle is observed, with the largest surface concentrations (12.93 ± 6.40 ppb) observed in June to August, and the lowest (4.08± 2.66 ppb) in November to January. The diurnal cycles of NH3 exhibit increased morning and afternoon concentrations. Interpretation of the diurnal cycles is difficult, however, the absence of a peak during rush hours, and the absence of correlation with CO and NO2 suggest that agriculture and not traffic is the main source of NH3 at Hefei. The polar plots of NH3 columns with wind and back trajectories of air masses calculated by the HYSPLIT model confirmed that agriculture was the dominant source of ammonia in four seasons, while urban anthropogenic emissions contributed to the high level of NH3 in summer over the Hefei site. We end this paper with a short validation exercise of NH3 columns retrieved from measurements of the IASI satellite data with the FTIR measurements over Hefei. Correlation coefficients (R) between the two datasets are 0.79 and 0.75 for IASI-A and IASI-B, with the slope of 0.96 and 1.10, respectively. The mean difference is −3.44 × 1015 and −3.96 × 1015 molec cm−2, with standard deviation of 7.16 × 1015 and 8.10 × 1015 molec cm−2, respectively. These results demonstrate the IASI and FTIR data, over Hefei, are in broad agreement. © 2022 The Authors
BibTeX:
@article{Wang2022,
  author = {Wang, Wei and Liu, Cheng and Clarisse, Lieven and VanDamme, Martin and Coheur, Pierre-François and Xie, Yu and Shan, Changgong and Hu, Qihou and Sun, Youwen and Jones, Nicholas},
  title = {Ground-based measurements of atmospheric NH3 by Fourier transform infrared spectrometry at Hefei and comparisons with IASI data},
  journal = {Atmospheric Environment},
  year = {2022},
  volume = {287},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.atmosenv.2022.119256}
}
Wespes C, Ronsmans G, Clarisse L, Solomon S, Hurtmans D, Clerbaux C and Coheur P-F (2022), "Polar stratospheric nitric acid depletion surveyed from a decadal dataset of IASI total columns", Atmospheric Chemistry and Physics. Vol. 22(16), pp. 10993 – 11007.
Abstract: In this paper, we exploit the first 10-year data record (2008–2017) of nitric acid (HNO3) total columns measured by the IASI-A/MetOp infrared sounder, characterized by an exceptional daily sampling and a good vertical sensitivity in the lower-to-mid stratosphere (around 50 hPa), to monitor the relationship between the temperature decrease and the observed HNO3 loss that occurs each year in the Antarctic stratosphere during the polar night. Since the HNO3 depletion results from the formation of polar stratospheric clouds (PSCs), which trigger the development of the ozone (O3) hole, its continuous monitoring is of high importance. We verify here, from the 10-year time evolution of HNO3 together with temperature (taken from reanalysis at 50 hPa), the recurrence of specific regimes in the annual cycle of IASI HNO3 and identify (for each year) the day and the 50 hPa temperature (“drop temperature”) corresponding to the onset of strong HNO3 depletion in the Antarctic winter. Although the measured HNO3 total column does not allow for the uptake of HNO3 by different types of PSC particles along the vertical profile to be differentiated, an average drop temperature of 194.2 ± 3.8 K, close to the nitric acid trihydrate (NAT) existence threshold (∼ 195 K at 50 hPa), is found in the region of potential vorticity lower than −10 × 10−5 K m2 kg−1 s−1 (similar to the 70–90◦ S equivalent latitude region during winter). The spatial distribution and interannual variability of the drop temperature are investigated and discussed. This paper highlights the capability of the IASI sounder to monitor the evolution of polar stratospheric HNO3, a key player in the processes involved in the depletion of stratospheric O3 © Author(s) 2022.
BibTeX:
@article{Wespes2022,
  author = {Wespes, Catherine and Ronsmans, Gaetane and Clarisse, Lieven and Solomon, Susan and Hurtmans, Daniel and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Polar stratospheric nitric acid depletion surveyed from a decadal dataset of IASI total columns},
  journal = {Atmospheric Chemistry and Physics},
  year = {2022},
  volume = {22},
  number = {16},
  pages = {10993 – 11007},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-22-10993-2022}
}
Whitburn S, Clarisse L, Crapeau M, August T, Hultberg T, Coheur PF and Clerbaux C (2022), "A CO2-independent cloud mask from Infrared Atmospheric Sounding Interferometer (IASI) radiances for climate applications", Atmospheric Measurement Techniques. Vol. 15(22), pp. 6653 – 6668.
Abstract: With more than 15 years of continuous and consistent measurements, the Infrared Atmospheric Sounding Interferometer (IASI) radiance dataset is becoming a reference climate data record. To be exploited to its full potential, it requires a cloud filter that is accurate, unbiased over the full IASI life span and strict enough to be used in satellite data retrieval schemes. Here, we present a new cloud detection algorithm which combines (1) a high sensitivity, (2) a good consistency over the whole IASI time series and between the different copies of the instrument flying on board the suite of Metop satellites, and (3) simplicity in its parametrization. The method is based on a supervised neural network (NN) and relies, as input parameters, on the IASI radiance measurements only. The robustness of the cloud mask over time is ensured in particular by avoiding the IASI channels that are influenced by CO2, N2O, CH4, CFC-11 and CFC-12 absorption lines and those corresponding to the ν2 H2O absorption band. As a reference dataset for the training, version 6.5 of the operational IASI Level 2 (L2) cloud product is used. We provide different illustrations of the NN cloud product, including comparisons with other existing products. We find very good agreement overall with version 6.5 of the operational IASI L2 with an identical mean annual cloud amount and a pixel-by-pixel correspondence of about 87 %. The comparison with the other cloud products shows a good correspondence in the main cloud regimes but with sometimes large differences in the mean cloud amount (up to 10 %) due to the specificities of each of the different products. We also show the good capability of the NN product to differentiate clouds from dust plumes. Copyright © 2022 Simon Whitburn et al.
BibTeX:
@article{Whitburn2022,
  author = {Whitburn, Simon and Clarisse, Lieven and Crapeau, Marc and August, Thomas and Hultberg, Tim and Coheur, Pierre François and Clerbaux, Cathy},
  title = {A CO2-independent cloud mask from Infrared Atmospheric Sounding Interferometer (IASI) radiances for climate applications},
  journal = {Atmospheric Measurement Techniques},
  year = {2022},
  volume = {15},
  number = {22},
  pages = {6653 – 6668},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-15-6653-2022}
}
Wright CJ, Hindley NP, Alexander MJ, Barlow M, Hoffmann L, Mitchell CN, Prata F, Bouillon M, Carstens J, Clerbaux C, Osprey SM, Powell N, Randall CE and Yue J (2022), "Surface-to-space atmospheric waves from Hunga Tonga–Hunga Ha’apai eruption", Nature. Vol. 609(7928), pp. 741 – 746.
Abstract: The January 2022 Hunga Tonga–Hunga Ha’apai eruption was one of the most explosive volcanic events of the modern era1,2, producing a vertical plume that peaked more than 50 km above the Earth3. The initial explosion and subsequent plume triggered atmospheric waves that propagated around the world multiple times4. A global-scale wave response of this magnitude from a single source has not previously been observed. Here we show the details of this response, using a comprehensive set of satellite and ground-based observations to quantify it from surface to ionosphere. A broad spectrum of waves was triggered by the initial explosion, including Lamb waves5,6 propagating at phase speeds of 318.2 ± 6 m s−1 at surface level and between 308 ± 5 to 319 ± 4 m s−1 in the stratosphere, and gravity waves7 propagating at 238 ± 3 to 269 ± 3 m s−1 in the stratosphere. Gravity waves at sub-ionospheric heights have not previously been observed propagating at this speed or over the whole Earth from a single source8,9. Latent heat release from the plume remained the most significant individual gravity wave source worldwide for more than 12 h, producing circular wavefronts visible across the Pacific basin in satellite observations. A single source dominating such a large region is also unique in the observational record. The Hunga Tonga eruption represents a key natural experiment in how the atmosphere responds to a sudden point-source-driven state change, which will be of use for improving weather and climate models. © 2022, The Author(s).
BibTeX:
@article{Wright2022,
  author = {Wright, Corwin J. and Hindley, Neil P. and Alexander, M. Joan and Barlow, Mathew and Hoffmann, Lars and Mitchell, Cathryn N. and Prata, Fred and Bouillon, Marie and Carstens, Justin and Clerbaux, Cathy and Osprey, Scott M. and Powell, Nick and Randall, Cora E. and Yue, Jia},
  title = {Surface-to-space atmospheric waves from Hunga Tonga–Hunga Ha’apai eruption},
  journal = {Nature},
  year = {2022},
  volume = {609},
  number = {7928},
  pages = {741 – 746},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1038/s41586-022-05012-5}
}
Xu W, Zhao Y, Wen Z, Chang Y, Pan Y, Sun Y, Ma X, Sha Z, Li Z, Kang J, Liu L, Tang A, Wang K, Zhang Y, Guo Y, Zhang L, Sheng L, Zhang X, Gu B, Song Y, VanDamme M, Clarisse L, Coheur P-F, Collett JL, Goulding K, Zhang F, He K and Liu X (2022), "Increasing importance of ammonia emission abatement in PM2.5 pollution control", Science Bulletin.
BibTeX:
@article{Xu2022,
  author = {Xu, Wen and Zhao, Yuanhong and Wen, Zhang and Chang, Yunhua and Pan, Yuepeng and Sun, Yele and Ma, Xin and Sha, Zhipeng and Li, Ziyue and Kang, Jiahui and Liu, Lei and Tang, Aohan and Wang, Kai and Zhang, Ying and Guo, Yixin and Zhang, Lin and Sheng, Lifang and Zhang, Xiuming and Gu, Baojing and Song, Yu and VanDamme, Martin and Clarisse, Lieven and Coheur, Pierre-François and Collett, Jeffrey L. and Goulding, Keith and Zhang, Fusuo and He, Kebin and Liu, Xuejun},
  title = {Increasing importance of ammonia emission abatement in PM2.5 pollution control},
  journal = {Science Bulletin},
  year = {2022},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.scib.2022.07.021}
}
Zhang CY, Li JQ, Wang K, Si R, Godefroid M, Jönsson P, Xiao J, Gu MF and Chen CY (2022), "Benchmarking calculations of wavelengths and transition rates with spectroscopic accuracy for W xlviii through W lvi tungsten ions", Physical Review A. Vol. 105(2)
Abstract: Atomic properties of n=3 levels for W47+-W55+ ions (Z=74) are systematically calculated using two different and independent methods, namely, the second-order many-body perturbation theory and the multiconfiguration Dirac-Hartree-Fock method combined with the relativistic configuration interaction approach. Wavelengths and transition rates for electric-and magnetic-dipole transitions involving the n=3 levels of W47+-W55+ are calculated. In addition, we discuss in detail the importance of the valence and core-valence electron correlations, the Breit interaction, the higher-order frequency-dependent retardation correction, and the leading quantum electrodynamical corrections for transition wavelengths. Spectroscopic accuracy is achieved for the present calculated wavelengths, and most of them agree with experimental values within 0.05%. Our calculated wavelengths, combined with collisional radiative model simulations, are used to identify the yet unidentified 25 observed lines in the extremely complex spectrum between 27Å and 34Å measured by Lennartsson etal. [Phys. Rev. A 87, 062505 (2013)10.1103/PhysRevA.87.062505]. We provide additional data for 472 strong electric-dipole transitions in the wavelength range of 17-50 Å, and 185 strong magnetic-dipole transitions between 36Å and 4384Å, with a line intensity greater than 1photon/s. These can provide benchmark data for future experiments and theoretical calculations. © 2022 American Physical Society.
BibTeX:
@article{Zhang2022,
  author = {Zhang, Chun Yu and Li, Jin Qing and Wang, Kai and Si, Ran and Godefroid, Michel and Jönsson, Per and Xiao, Jun and Gu, Ming Feng and Chen, Chong Yang},
  title = {Benchmarking calculations of wavelengths and transition rates with spectroscopic accuracy for W xlviii through W lvi tungsten ions},
  journal = {Physical Review A},
  year = {2022},
  volume = {105},
  number = {2},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.105.022817}
}
Abeed R, Clerbaux C, Clarisse L, VanDamme M, Coheur P-F and Safieddine S (2021), "A space view of agricultural and industrial changes during the Syrian civil war", Elementa. Vol. 9(1)
Abstract: The agricultural sector in Syria was heavily affected by the civil war that started in 2011. We investigate the war’s impact on the country’s atmospheric ammonia (NH3) from 2008 to 2019, using measurements from the infrared atmospheric sounding interferometer instrument on board the Metop satellites. We examine the changes in NH3 close to a fertilizer industry, whose activities were suspended due to conflict-related events. We also explore the effect of war-induced land use/land cover changes on agriculture-emitted ammonia in north-east Syria that has witnessed battles between different groups. The interpretation of the changes in NH3 is supported by different datasets: visible satellite imagery to assess the effect on industrial activity, reanalysis data from the European center for medium-range weather forecasts to look at the effect of meteorology (temperature, wind speed, and precipitation), and land cover and burned area products from the moderate resolution imaging spectroradiometer (MODIS) to examine land use/land cover changes and fire events during the study period. We show that the NH3 columns are directly affected by the war. Periods of intense conflict are reflected in lower values over the industry reaching –17%, –47%, and –32% in 2013, 2014, and 2016, respectively, compared to the [2008–2012] average, and a decrease reaching –14% and –15% in the croplands’ area in northeast Syria during 2017 and 2018 (compared to 2011), respectively. Toward the end of the control of Islamic State in Iraq and Syria, an increase in atmospheric NH3 was accompanied by an increase in croplands’ area that reached up to þ35% in 2019 as compared to prewar (2011). This study shows the relevance of remote-sensing data of atmospheric composition in studying societal changes at a local and regional scale. © 2021 The Author(s).
BibTeX:
@article{Abeed2021,
  author = {Abeed, Rimal and Clerbaux, Cathy and Clarisse, Lieven and VanDamme, Martin and Coheur, Pierre-François and Safieddine, Sarah},
  title = {A space view of agricultural and industrial changes during the Syrian civil war},
  journal = {Elementa},
  year = {2021},
  volume = {9},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1525/elementa.2021.000041}
}
Aerts A, VanderAuwera J and Vaeck N (2021), "Lindblad parameters from high resolution spectroscopy to describe collision-induced rovibrational decoherence in the gas phase - Application to acetylene", Journal of Chemical Physics. Vol. 154(14)
Abstract: Within the framework of the Lindblad master equation, we propose a general methodology to describe the effects of the environment on a system in the dilute gas phase. The phenomenological parameters characterizing the transitions between rovibrational states of the system induced by collisions can be extracted from experimental transition kinetic constants, relying on energy gap fitting laws. As the availability of these kinds of experimental data can be limited, this work relied on experimental line broadening coefficients, however still using energy gap fitting laws. The 3 μm infrared spectral range of acetylene was chosen to illustrate the proposed approach. The method shows fair agreement with available experimental data while being computationally inexpensive. The results are discussed in the context of state laser quantum control. © 2021 Author(s).
BibTeX:
@article{Aerts2021,
  author = {Aerts, Antoine and VanderAuwera, Jean and Vaeck, Nathalie},
  title = {Lindblad parameters from high resolution spectroscopy to describe collision-induced rovibrational decoherence in the gas phase - Application to acetylene},
  journal = {Journal of Chemical Physics},
  year = {2021},
  volume = {154},
  number = {14},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/5.0045275}
}
Aydogan A, Bangle RE, Cadranel A, Turlington MD, Conroy DT, Cauët E, Singleton ML, Meyer GJ, Sampaio RN, Elias B and Troian-Gautier L (2021), "Accessing Photoredox Transformations with an Iron(III) Photosensitizer and Green Light", Journal of the American Chemical Society. Vol. 143(38), pp. 15661 – 15673.
Abstract: Efficient excited-state electron transfer between an iron(III) photosensitizer and organic electron donors was realized with green light irradiation. This advance was enabled by the use of the previously reported iron photosensitizer, [Fe(phtmeimb)2]+ (phtmeimb = phenyl[tris(3-methyl-imidazolin-2-ylidene)]borate, that exhibited long-lived and luminescent ligand-to-metal charge-transfer (LMCT) excited states. A benchmark dehalogenation reaction was investigated with yields that exceed 90% and an enhanced stability relative to the prototypical photosensitizer [Ru(bpy)3]2+. The initial catalytic step is electron transfer from an amine to the photoexcited iron sensitizer, which is shown to occur with a large cage-escape yield. For LMCT excited states, this reductive electron transfer is vectorial and may be a general advantage of Fe(III) photosensitizers. In-depth time-resolved spectroscopic methods, including transient absorption characterization from the ultraviolet to the infrared regions, provided a quantitative description of the catalytic mechanism with associated rate constants and yields. © 2021 American Chemical Society.
BibTeX:
@article{Aydogan2021,
  author = {Aydogan, Akin and Bangle, Rachel E. and Cadranel, Alejandro and Turlington, Michael D. and Conroy, Daniel T. and Cauët, Emilie and Singleton, Michael L. and Meyer, Gerald J. and Sampaio, Renato N. and Elias, Benjamin and Troian-Gautier, Ludovic},
  title = {Accessing Photoredox Transformations with an Iron(III) Photosensitizer and Green Light},
  journal = {Journal of the American Chemical Society},
  year = {2021},
  volume = {143},
  number = {38},
  pages = {15661 – 15673},
  note = {All Open Access, Green Open Access},
  doi = {10.1021/jacs.1c06081}
}
Aydogan A, Bangle RE, DeKreijger S, Dickenson JC, Singleton ML, Cauët E, Cadranel A, Meyer GJ, Elias B, Sampaio RN and Troian-Gautier L (2021), "Mechanistic investigation of a visible light mediated dehalogenation/cyclisation reaction using iron(iii), iridium(iii) and ruthenium(ii) photosensitizers", Catalysis Science and Technology. Vol. 11(24), pp. 8037 – 8051.
Abstract: The mechanism of a visible light-driven dehalogenation/cyclization reaction was investigated using ruthenium(ii), iridium(iii) and iron(iii) photosensitizers by means of steady-state photoluminescence, time-resolved infrared spectroscopy, and nanosecond/femtosecond transient absorption spectroscopy. The nature of the photosensitizer was found to influence the product distribution such that the dehalogenated, non-cyclized products were only detected for the iron photosensitizer. Strikingly, with the iron photosensitizer, large catalytic yields required a low dielectric solvent such as dichloromethane, consistent with a previous publication. This low dielectric solvent allowed ultrafast charge-separation to outcompete geminate charge recombination and improved cage escape efficiency. Further, the identification of reaction mechanisms unique to the iron, ruthenium, and iridium photosensitizer represents progress towards the long-sought goal of utilizing earth-abundant, first-row transition metals for emerging energy and environmental applications. © The Royal Society of Chemistry 2021.
BibTeX:
@article{Aydogan2021a,
  author = {Aydogan, Akin and Bangle, Rachel E. and DeKreijger, Simon and Dickenson, John C. and Singleton, Michael L. and Cauët, Emilie and Cadranel, Alejandro and Meyer, Gerald J. and Elias, Benjamin and Sampaio, Renato N. and Troian-Gautier, Ludovic},
  title = {Mechanistic investigation of a visible light mediated dehalogenation/cyclisation reaction using iron(iii), iridium(iii) and ruthenium(ii) photosensitizers},
  journal = {Catalysis Science and Technology},
  year = {2021},
  volume = {11},
  number = {24},
  pages = {8037 – 8051},
  doi = {10.1039/d1cy01771c}
}
Barzakh A, Andreyev A, Raison C, Cubiss J, Van Duppen P, Péru S, Hilaire S, Goriely S, Andel B, Antalic S, Al Monthery M, Berengut J, Bieroń J, Bissell M, Borschevsky A, Chrysalidis K, Cocolios T, Day Goodacre T, Dognon J-P, Elantkowska M, Eliav E, Farooq-Smith G, Fedorov D, Fedosseev V, Gaffney L, Garcia Ruiz R, Godefroid M, Granados C, Harding R, Heinke R, Huyse M, Karls J, Larmonier P, Li J, Lynch K, Maison D, Marsh B, Molkanov P, Mosat P, Oleynichenko A, Panteleev V, Pyykkö P, Reitsma M, Rezynkina K, Rossel R, Rothe S, Ruczkowski J, Schiffmann S, Seiffert C, Seliverstov M, Sels S, Skripnikov L, Stryjczyk M, Studer D, Verlinde M, Wilman S and Zaitsevskii A (2021), "Large Shape Staggering in Neutron-Deficient Bi Isotopes", Physical Review Letters. Vol. 127(19)
Abstract: The changes in the mean-square charge radius (relative to Bi209), magnetic dipole, and electric quadrupole moments of Bi187,188,189,191 were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in Bi187,188,189g, manifested by a sharp radius increase for the ground state of Bi188 relative to the neighboring Bi187,189g. A large isomer shift was also observed for Bi188m. Both effects happen at the same neutron number, N=105, where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment. © 2021 authors.
BibTeX:
@article{Barzakh2021,
  author = {Barzakh, A. and Andreyev, A.N. and Raison, C. and Cubiss, J.G. and Van Duppen, P. and Péru, S. and Hilaire, S. and Goriely, S. and Andel, B. and Antalic, S. and Al Monthery, M. and Berengut, J.C. and Bieroń, J. and Bissell, M.L. and Borschevsky, A. and Chrysalidis, K. and Cocolios, T.E. and Day Goodacre, T. and Dognon, J.-P. and Elantkowska, M. and Eliav, E. and Farooq-Smith, G.J. and Fedorov, D.V. and Fedosseev, V.N. and Gaffney, L.P. and Garcia Ruiz, R.F. and Godefroid, M. and Granados, C. and Harding, R.D. and Heinke, R. and Huyse, M. and Karls, J. and Larmonier, P. and Li, J.G. and Lynch, K.M. and Maison, D.E. and Marsh, B.A. and Molkanov, P. and Mosat, P. and Oleynichenko, A.V. and Panteleev, V. and Pyykkö, P. and Reitsma, M.L. and Rezynkina, K. and Rossel, R.E. and Rothe, S. and Ruczkowski, J. and Schiffmann, S. and Seiffert, C. and Seliverstov, M.D. and Sels, S. and Skripnikov, L.V. and Stryjczyk, M. and Studer, D. and Verlinde, M. and Wilman, S. and Zaitsevskii, A.V.},
  title = {Large Shape Staggering in Neutron-Deficient Bi Isotopes},
  journal = {Physical Review Letters},
  year = {2021},
  volume = {127},
  number = {19},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1103/PhysRevLett.127.192501}
}
Bauduin S, Giuranna M, Wolkenberg P, Nardi L, Daerden F, Bouche J, Wespes C, Lecomte G, Vandaele AC and Coheur P (2021), "Exploiting night-time averaged spectra from PFS/MEX shortwave channel. Part 1: Temperature retrieval from the CO2 ν3 band", Planetary and Space Science. Vol. 198
Abstract: Nadir remote sensing of the night side of Mars is challenging, mainly due to the low signal-to-noise ratio of such observations. We show in a companion paper that the abundance of carbon monoxide (CO) during night can be retrieved from the observations of the Planetary Fourier Spectrometer (PFS). This requires, however, an accurate knowledge of the temperature profile, and especially of the night-time thermal inversions, to properly model the atmospheric emission. While the temperature profile is usually retrieved from the ν2 band of CO2 (centered at 667 ​cm−1), this work shows that, for averaged night-time PFS observations built from a large ensemble of spectra, the temperature profile can be retrieved from the more saturated ν3 band of CO2 (centered at 2349 ​cm−1). We show especially that, due to IFOV (instantaneous field-of-view) size differences and boresight offset between the longwave and shortwave channels of PFS, the temperature profile retrieved from the ν3 band is more consistent with the emission observed in the 1-0 band of CO (centered at 2143 ​cm−1), which is used in the second part paper. We provide a complete characterization of the retrieved temperature profiles in terms of error and vertical sensitivity. Using this, we show that using the ν3 CO2 band allows to properly constrain and characterize the thermal inversions encountered near the surface for most night-time observations. The resulting set of temperature profiles is essential for the retrieval of the night-time CO abundance that is presented in the companion paper. Beyond their usefulness for the night-time CO retrieval, we suggest with a last example that temperature profiles retrieved from the ν3 band of CO2 could be use more generally to study surface thermal inversions encountered at night. © 2021 Elsevier Ltd
BibTeX:
@article{Bauduin2021,
  author = {Bauduin, Sophie and Giuranna, Marco and Wolkenberg, Paulina and Nardi, Luca and Daerden, Frank and Bouche, Jimmy and Wespes, Catherine and Lecomte, Gilles and Vandaele, Ann Carine and Coheur, Pierre},
  title = {Exploiting night-time averaged spectra from PFS/MEX shortwave channel. Part 1: Temperature retrieval from the CO2 ν3 band},
  journal = {Planetary and Space Science},
  year = {2021},
  volume = {198},
  doi = {10.1016/j.pss.2021.105186}
}
Bauduin S, Giuranna M, Wolkenberg P, Nardi L, Daerden F, Bouche J, Wespes C, Lecomte G, Vandaele AC and Coheur P (2021), "Exploiting night-time averaged spectra from PFS/MEX shortwave channel. Part 2: Near-surface CO retrievals", Planetary and Space Science. Vol. 199
Abstract: Because of its important role in the Martian carbon cycle, carbon monoxide (CO) has been the subject of many measurements from ground and from space. Daytime measurements have been mostly exploited to measure the CO abundance because of their good signal-to-noise ratio, but night-time observations have not been documented yet. We demonstrate here the possibility of using PFS (Planetary Fourier Spectrometer) night-time observations to measure the Martian CO abundance. More particularly in this paper, we show that measuring CO during night with PFS can be achieved by averaging a large number of spectra to reach sufficient signal-to-noise. Furthermore, we show that the number of averaged spectra is not the only driving parameter for the detection of CO. High surface temperatures and high thermal contrast (negative in our case) are the two other conditions required for the measurement of the night-time CO abundance. Because of this, the retrievals are especially successful in the Southern Hemisphere during spring and summer when and where these two conditions are met. For night-time spectra with a positive detection, CO vertical profiles are successfully retrieved using the Optimal Estimation method and are characterized in terms of vertical sensitivity. Successful retrievals imply the use of accurate temperature profiles, and in particular an appropriate representation of the thermal inversion in the lower atmosphere. The temperature was obtained by using the relevant information from the CO2 ν3 band (Bauduin et al., 2020, this issue). A complete error budget of the retrieved CO profiles is also performed and includes different sources of uncertainty. Although the retrieved profiles are not resolved vertically, we show in particular that night-time PFS observations carry information mostly on the CO abundance for the 0–10 ​km altitude region, and thus provide a stronger constraint on the near-surface CO abundance compared to daytime observations. © 2021
BibTeX:
@article{Bauduin2021a,
  author = {Bauduin, Sophie and Giuranna, Marco and Wolkenberg, Paulina and Nardi, Luca and Daerden, Frank and Bouche, Jimmy and Wespes, Catherine and Lecomte, Gilles and Vandaele, Ann Carine and Coheur, Pierre},
  title = {Exploiting night-time averaged spectra from PFS/MEX shortwave channel. Part 2: Near-surface CO retrievals},
  journal = {Planetary and Space Science},
  year = {2021},
  volume = {199},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.pss.2021.105188}
}
Bègue N, Bencherif H, Jégou F, Vérèmes H, Khaykin S, Krysztofiak G, Portafaix T, Duflot V, Baron A, Berthet G, Kloss C, Payen G, Keckhut P, Coheur P-F, Clerbaux C, Smale D, Robinson J, Querel R and Smale P (2021), "Transport and variability of tropospheric ozone over oceania and southern pacific during the 2019–20 australian bushfires", Remote Sensing. Vol. 13(16)
Abstract: The present study contributes to the scientific effort for a better understanding of the potential of the Australian biomass burning events to influence tropospheric trace gas abundances at the regional scale. In order to exclude the influence of the long-range transport of ozone precursors from biomass burning plumes originating from Southern America and Africa, the analysis of the Australian smoke plume has been driven over the period December 2019 to January 2020. This study uses satellite (IASI, MLS, MODIS, CALIOP) and ground-based (sun-photometer, FTIR, ozone radiosondes) observations. The highest values of aerosol optical depth (AOD) and carbon monoxide total columns are observed over Southern and Central Australia. Transport is responsible for the spatial and temporal distributions of aerosols and carbon monoxide over Australia, and also the transport of the smoke plume outside the continent. The dispersion of the tropospheric smoke plume over Oceania and Southern Pacific extends from tropical to extratropical latitudes. Ozone radiosonde measurements performed at Samoa (14.4◦S, 170.6◦W) and Lauder (45.0◦S, 169.4◦E) indicate an increase in mid-tropospheric ozone (6–9 km) (from 10% to 43%) linked to the Australian biomass burning plume. This increase in mid-tropospheric ozone induced by the transport of the smoke plume was found to be consistent with MLS observations over the tropical and extratropical latitudes. The smoke plume over the Southern Pacific was organized as a stretchable anticyclonic rolling which impacted the ozone variability in the tropical and subtropical upper-troposphere over Oceania. This is corroborated by the ozone profile measurements at Samoa which exhibit an enhanced ozone layer (29%) in the upper-troposphere. Our results suggest that the transport of Australian biomass burning plumes have significantly impacted the vertical distribution of ozone in the mid-troposphere southern tropical to extratropical latitudes during the 2019–20 extreme Australian bushfires. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Begue2021,
  author = {Bègue, Nelson and Bencherif, Hassan and Jégou, Fabrice and Vérèmes, Hélène and Khaykin, Sergey and Krysztofiak, Gisèle and Portafaix, Thierry and Duflot, Valentin and Baron, Alexandre and Berthet, Gwenaël and Kloss, Corinna and Payen, Guillaume and Keckhut, Philippe and Coheur, Pierre-François and Clerbaux, Cathy and Smale, Dan and Robinson, John and Querel, Richard and Smale, Penny},
  title = {Transport and variability of tropospheric ozone over oceania and southern pacific during the 2019–20 australian bushfires},
  journal = {Remote Sensing},
  year = {2021},
  volume = {13},
  number = {16},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/rs13163092}
}
Bernath PF, Johnson R and Liévin J (2021), "Line lists for the b1Σ+-X3Σ− and a1Δ-X3Σ− transitions of SO", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 272
Abstract: SO is found in many astronomical sources such as the atmospheres of Io and Venus. In order to create more complete line lists, we fit spectroscopic data on SO from the literature using PGOPHER. The fits covered v = 0 to v = 6 for the X3Σ−state, v = 0–5 for the a1Δ state and v = 0–2 for b1Σ+ state. LeRoy's RKR program was used to produce pointwise potential energy curves. High level ab initio calculations, including spin-orbit coupling, were carried out to obtain the electric transition dipole moment functions for the nominally forbidden b1Σ+-X3Σ−and a1Δ-X3Σ−transitions. The RKR potentials and transition dipole moment points were input into LeRoy's LEVEL program to calculate the transition dipole matrix elements for all possible b-X and a-X bands. For the b1Σ+-X3Σ−transition, the electric and magnetic transition dipole matrix elements were scaled using the experimental values obtained by Setzer et al. [J Mol Spectrosc 1999;198:163–174] for the 0–0 band. The transition dipole moment matrix elements were used in PGOPHER to produce our line lists for all possible bands of the b1Σ+-X3Σ−and a1Δ-X3Σ−transitions. © 2021 Elsevier Ltd
BibTeX:
@article{Bernath2021,
  author = {Bernath, Peter F. and Johnson, Ryan and Liévin, Jacques},
  title = {Line lists for the b1Σ+-X3Σ− and a1Δ-X3Σ− transitions of SO},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2021},
  volume = {272},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2021.107772}
}
Bogomolov A, Roucou A, Bejjani R, Herman M, Moazzen-Ahmadi N and Lauzin C (2021), "The rotationally resolved symmetric 2OH excitation in H2O-CO2 observed using pulsed supersonic expansion and CW-CRDS", Chemical Physics Letters. Vol. 774
Abstract: The rovibrational band corresponding to a double excitation of the OH symmetric stretch of the H2O unit in the H2O-CO2 van der Waals complex has been recorded using CW-CRDS and a pulsed slit expansion seeded in He. The set-up is presented. The rotational analysis of this band is detailed and the results of the global fit of these data with those of the other 2OH excitation band and of the ground vibrational states are reported including data from the literature. The tunneling frequency and the vibrational predissociation lifetime are shown to decrease with vibrational excitation. © 2021
BibTeX:
@article{Bogomolov2021,
  author = {Bogomolov, A.S. and Roucou, A. and Bejjani, R. and Herman, M. and Moazzen-Ahmadi, N. and Lauzin, C.},
  title = {The rotationally resolved symmetric 2OH excitation in H2O-CO2 observed using pulsed supersonic expansion and CW-CRDS},
  journal = {Chemical Physics Letters},
  year = {2021},
  volume = {774},
  doi = {10.1016/j.cplett.2021.138606}
}
Boualili FZ, Nemouchi M, Godefroid M and Jönsson P (2021), "Weak correlation and strong relativistic effects on the hyperfine interaction in fluorine", Physical Review A. Vol. 104(6)
Abstract: In previous work devoted to ab initio calculations of hyperfine-structure constants in nitrogen and fluorine atoms, we observed sizable relativistic effects, a priori unexpected for such light systems, that can even largely dominate over electron correlation. We observed that the atomic wave functions calculated in the Breit-Pauli approximation describe adequately the relevant atomic levels and hyperfine structures, even in cases for which a small relativistic LS-term mixing becomes crucial. In the present work we identify levels belonging to the spectroscopic terms 2p4(3P)3d2,4(P,D,F) of the fluorine atom, for which correlation effects on the hyperfine structures are small, but relativistic LS-term admixtures are decisive to correctly reproduce the experimental values. The Breit-Pauli analysis of the hyperfine matrix elements nails cases with large cancellation, either between LS pairs for individual hyperfine operators or between the orbital and the spin dipole contributions. Multiconfiguration Dirac-Hartree-Fock calculations are performed to support the Breit-Pauli analysis. © 2021 American Physical Society
BibTeX:
@article{Boualili2021,
  author = {Boualili, Fatima Zahra and Nemouchi, Messaoud and Godefroid, Michel and Jönsson, Per},
  title = {Weak correlation and strong relativistic effects on the hyperfine interaction in fluorine},
  journal = {Physical Review A},
  year = {2021},
  volume = {104},
  number = {6},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.104.062813}
}
Bouche J, Coheur P-F, Giuranna M, Wolkenberg P, Nardi L, Amoroso M, Vandaele AC, Daerden F, Neary L and Bauduin S (2021), "Seasonal and Spatial Variability of Carbon Monoxide (CO) in the Martian Atmosphere From PFS/MEX Observations", Journal of Geophysical Research: Planets. Vol. 126(2)
Abstract: A subset of more than 100,000 nadir measurements covering more than 7 Martian years (MY 26–MY 33) recorded in the thermal part of the Short Wavelength Channel (SWC) from the Planetary Fourier Spectrometer (PFS) on board Mars Express is exploited to investigate the global distribution and the seasonal cycle of carbon monoxide (CO) on Mars. The retrieval of CO vertical profiles is successfully achieved using a methodology based on the optimal estimation but the low information content is such that we mainly discuss the variability in CO in terms of integrated columns (from the surface to 24 km) or the associated column-averaged mixing ratio. We find a strong seasonality in CO, especially at mid and high-latitudes, which confirms earlier work and the current knowledge of the CO2 condensation/sublimation cycles, as implemented for instance in the Global Environmental Multiscale (GEM) general circulation model for Mars, that we use as a basis for comparison. We report a general consistency between model and observation, with a tendency of the latter to provide lower CO volume mixing ratios (VMRs), except at low latitudes. The spatial distribution of the CO column-averaged VMR is obtained on a seasonal basis and investigated in terms of large-scale patterns but also local peculiarities. Finally, we show that the retrieved profiles systematically present strong CO vertical gradients close to the surface in mid- and equatorial latitudes, likely related to the vertical sensitivity of PFS rather than real near-surface CO enrichment. © 2021. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Bouche2021,
  author = {Bouche, Jimmy and Coheur, Pierre-François and Giuranna, Marco and Wolkenberg, Paulina and Nardi, Luca and Amoroso, Marilena and Vandaele, Ann Carine and Daerden, Frank and Neary, Lori and Bauduin, Sophie},
  title = {Seasonal and Spatial Variability of Carbon Monoxide (CO) in the Martian Atmosphere From PFS/MEX Observations},
  journal = {Journal of Geophysical Research: Planets},
  year = {2021},
  volume = {126},
  number = {2},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2020JE006480}
}
Bowen K, Hillenbrand P-M, Liévin J, Savin D and Urbain X (2021), "Dynamics of the isotope exchange reaction of D with H 3 +, H2D+, and D2H+", Journal of Chemical Physics. Vol. 154(8)
Abstract: We have measured the merged-beams rate coefficient for the titular isotope exchange reactions as a function of the relative collision energy in the range of ∼3 meV-10 eV. The results appear to scale with the number of available sites for deuteration. We have performed extensive theoretical calculations to characterize the zero-point energy corrected reaction path. Vibrationally adiabatic minimum energy paths were obtained using a combination of unrestricted quadratic configuration interaction of single and double excitations and internally contracted multireference configuration interaction calculations. The resulting barrier height, ranging from 68 meV to 89 meV, together with the various asymptotes that may be reached in the collision, was used in a classical over-the-barrier model. All competing endoergic reaction channels were taken into account using a flux reduction factor. This model reproduces all three experimental sets quite satisfactorily. In order to generate thermal rate coefficients down to 10 K, the internal excitation energy distribution of each H3+ isotopologue is evaluated level by level using available line lists and accurate spectroscopic parameters. Tunneling is accounted for by a direct inclusion of the exact quantum tunneling probability in the evaluation of the cross section. We derive a thermal rate coefficient of <1×10-12 cm3 s-1 for temperatures below 44 K, 86 K, and 139 K for the reaction of D with H3+, H2D+, and D2H+, respectively, with tunneling effects included. The derived thermal rate coefficients exceed the ring polymer molecular dynamics prediction of Bulut et al. [J. Phys. Chem. A 123, 8766 (2019)] at all temperatures. © 2021 Author(s).
BibTeX:
@article{Bowen2021,
  author = {Bowen, K.P. and Hillenbrand, P.-M. and Liévin, J. and Savin, D.W. and Urbain, X.},
  title = {Dynamics of the isotope exchange reaction of D with H 3 +, H2D+, and D2H+},
  journal = {Journal of Chemical Physics},
  year = {2021},
  volume = {154},
  number = {8},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1063/5.0038434}
}
Brenot H, Theys N, Clarisse L, VanGent J, Hurtmans DR, Vandenbussche S, Papagiannopoulos N, Mona L, Virtanen T, Uppstu A, Sofiev M, Bugliaro L, Vázquez-Navarro M, Hedelt P, Parks MM, Barsotti S, Coltelli M, Moreland W, Scollo S, Salerno G, Arnold-Arias D, Hirtl M, Peltonen T, Lahtinen J, Sievers K, Lipok F, Rüfenacht R, Haefele A, Hervo M, Wagenaar S, Som De Cerff W, De Laat J, Apituley A, Stammes P, Laffineur Q, Delcloo A, Lennart R, Rokitansky C-H, Vargas A, Kerschbaum M, Resch C, Zopp R, Plu M, Peuch V-H, vanRoozendael M and Wotawa G (2021), "EUNADICS-AV early warning system dedicated to supporting aviation in the case of a crisis from natural airborne hazards and radionuclide clouds", Natural Hazards and Earth System Sciences. Vol. 21(11), pp. 3367 – 3405.
Abstract: The purpose of the EUNADICS-AV (European Natural Airborne Disaster Information and Coordination System for Aviation) prototype early warning system (EWS) is to develop the combined use of harmonised data products from satellite, ground-based and in situ instruments to produce alerts of airborne hazards (volcanic, dust, smoke and radionuclide clouds), satisfying the requirement of aviation air traffic management (ATM) stakeholders (https://cordis.europa.eu/project/id/723986, last access: 5 November 2021). The alert products developed by the EUNADICS-AV EWS, i.e. near-real-time (NRT) observations, email notifications and netCDF (Network Common Data Form) alert data products (called NCAP files), have shown significant interest in using selective detection of natural airborne hazards from polar-orbiting satellites. The combination of several sensors inside a single global system demonstrates the advantage of using a triggered approach to obtain selective detection from observations, which cannot initially discriminate the different aerosol types. Satellite products from hyperspectral ultraviolet-visible (UV-vis) and infrared (IR) sensors (e.g. TROPOMI - TROPOspheric Monitoring Instrument - and IASI - Infrared Atmospheric Sounding Interferometer) and a broadband geostationary imager (Spinning Enhanced Visible and InfraRed Imager; SEVIRI) and retrievals from ground-based networks (e.g. EARLINET - European Aerosol Research Lidar Network, E-PROFILE and the regional network from volcano observatories) are combined by our system to create tailored alert products (e.g. selective ash detection, SO2 column and plume height, dust cloud, and smoke from wildfires). A total of 23 different alert products are implemented, using 1 geostationary and 13 polar-orbiting satellite platforms, 3 external existing service, and 2 EU and 2 regional ground-based networks. This allows for the identification and the tracking of extreme events. The EUNADICS-AV EWS has also shown the need to implement a future relay of radiological data (gamma dose rate and radionuclides concentrations in ground-level air) in the case of a nuclear accident. This highlights the interest of operating early warnings with the use of a homogenised dataset. For the four types of airborne hazard, the EUNADICS-AV EWS has demonstrated its capability to provide NRT alert data products to trigger data assimilation and dispersion modelling providing forecasts and inverse modelling for source term estimate. Not all of our alert data products (NCAP files) are publicly disseminated. Access to our alert products is currently restricted to key users (i.e. Volcanic Ash Advisory Centres, national meteorological services, the World Meteorological Organization, governments, volcano observatories and research collaborators), as these are considered pre-decisional products. On the other hand, thanks to the EUNADICS-AV-SACS (Support to Aviation Control Service) web interface (https://sacs.aeronomie.be, last access: 5 November 2021), the main part of the satellite observations used by the EUNADICS-AV EWS is shown in NRT, with public email notification of volcanic emission and delivery of tailored images and NCAP files. All of the ATM stakeholders (e.g. pilots, airlines and passengers) can access these alert products through this free channel. © Author(s) 2021.
BibTeX:
@article{Brenot2021,
  author = {Brenot, Hugues and Theys, Nicolas and Clarisse, Lieven and VanGent, Jeroen and Hurtmans, Daniel R. and Vandenbussche, Sophie and Papagiannopoulos, Nikolaos and Mona, Lucia and Virtanen, Timo and Uppstu, Andreas and Sofiev, Mikhail and Bugliaro, Luca and Vázquez-Navarro, Margarita and Hedelt, Pascal and Parks, Michelle Maree and Barsotti, Sara and Coltelli, Mauro and Moreland, William and Scollo, Simona and Salerno, Giuseppe and Arnold-Arias, Delia and Hirtl, Marcus and Peltonen, Tuomas and Lahtinen, Juhani and Sievers, Klaus and Lipok, Florian and Rüfenacht, Rolf and Haefele, Alexander and Hervo, Maxime and Wagenaar, Saskia and Som De Cerff, Wim and De Laat, Jos and Apituley, Arnoud and Stammes, Piet and Laffineur, Quentin and Delcloo, Andy and Lennart, Robertson and Rokitansky, Carl-Herbert and Vargas, Arturo and Kerschbaum, Markus and Resch, Christian and Zopp, Raimund and Plu, Matthieu and Peuch, Vincent-Henri and vanRoozendael, Michel and Wotawa, Gerhard},
  title = {EUNADICS-AV early warning system dedicated to supporting aviation in the case of a crisis from natural airborne hazards and radionuclide clouds},
  journal = {Natural Hazards and Earth System Sciences},
  year = {2021},
  volume = {21},
  number = {11},
  pages = {3367 – 3405},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/nhess-21-3367-2021}
}
Buchholz RR, Worden HM, Park M, Francis G, Deeter MN, Edwards DP, Emmons LK, Gaubert B, Gille J, Martínez-Alonso S, Tang W, Kumar R, Drummond JR, Clerbaux C, George M, Coheur P-F, Hurtmans D, Bowman KW, Luo M, Payne VH, Worden JR, Chin M, Levy RC, Warner J, Wei Z and Kulawik SS (2021), "Air pollution trends measured from Terra: CO and AOD over industrial, fire-prone, and background regions", Remote Sensing of Environment. Vol. 256
Abstract: Following past studies to quantify decadal trends in global carbon monoxide (CO) using satellite observations, we update estimates and find a CO trend in column amounts of about −0.50 % per year between 2002 to 2018, which is a deceleration compared to analyses performed on shorter records that found −1 % per year. Aerosols are co-emitted with CO from both fires and anthropogenic sources but with a shorter lifetime than CO. A combined trend analysis of CO and aerosol optical depth (AOD) measurements from space helps to diagnose the drivers of regional differences in the CO trend. We use the long-term records of CO from the Measurements of Pollution in the Troposphere (MOPITT) and AOD from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. Other satellite instruments measuring CO in the thermal infrared, AIRS, TES, IASI, and CrIS, show consistent hemispheric CO variability and corroborate results from the trend analysis performed with MOPITT CO. Trends are examined by hemisphere and in regions for 2002 to 2018, with uncertainties quantified. The CO and AOD records are split into two sub-periods (2002 to 2010 and 2010 to 2018) in order to assess trend changes over the 16 years. We focus on four major population centers: Northeast China, North India, Europe, and Eastern USA, as well as fire-prone regions in both hemispheres. In general, CO declines faster in the first half of the record compared to the second half, while AOD trends show more variability across regions. We find evidence of the atmospheric impact of air quality management policies. The large decline in CO found over Northeast China is initially associated with an improvement in combustion efficiency, with subsequent additional air quality improvements from 2010 onwards. Industrial regions with minimal emission control measures such as North India become more globally relevant as the global CO trend weakens. We also examine the CO trends in monthly percentile values to understand seasonal implications and find that local changes in biomass burning are sufficiently strong to counteract the global downward trend in atmospheric CO, particularly in late summer. © 2020 The Author(s)
BibTeX:
@article{Buchholz2021,
  author = {Buchholz, Rebecca R. and Worden, Helen M. and Park, Mijeong and Francis, Gene and Deeter, Merritt N. and Edwards, David P. and Emmons, Louisa K. and Gaubert, Benjamin and Gille, John and Martínez-Alonso, Sara and Tang, Wenfu and Kumar, Rajesh and Drummond, James R. and Clerbaux, Cathy and George, Maya and Coheur, Pierre-François and Hurtmans, Daniel and Bowman, Kevin W. and Luo, Ming and Payne, Vivienne H. and Worden, John R. and Chin, Mian and Levy, Robert C. and Warner, Juying and Wei, Zigang and Kulawik, Susan S.},
  title = {Air pollution trends measured from Terra: CO and AOD over industrial, fire-prone, and background regions},
  journal = {Remote Sensing of Environment},
  year = {2021},
  volume = {256},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.rse.2020.112275}
}
Chang Y, Zhang Y-L, Kawichai S, Wang Q, VanDamme M, Clarisse L, Prapamontol T and Lehmann MF (2021), "Convergent evidence for the pervasive but limited contribution of biomass burning to atmospheric ammonia in peninsular Southeast Asia", Atmospheric Chemistry and Physics. Vol. 21(9), pp. 7187 – 7198.
Abstract: Ammonia (NH3) is an important agent involved in atmospheric chemistry and nitrogen cycling. Current estimates of NH3 emissions from biomass burning (BB) differ by more than a factor of 2, impeding a reliable assessment of their environmental consequences. Combining highresolution satellite observations of NH3 columns with network measurements of the concentration and stable nitrogen isotope composition (δ15N) of NH3, we present coherent estimates of the amount of NH3 derived from BB in the heartland of Southeast Asia, a tropical monsoon environment. Our results reveal a strong variability in atmospheric NH3 levels in time and space across different landscapes. All of the evidence on hand suggests that anthropogenic activities are the most important modulating control with respect to the observed patterns of NH3 distribution in the study area. Nisotope balance considerations revealed that during the intensive fire period, the atmospheric input from BB accounts for no more than 21 ± 5 % (1s) of the ambient NH3, even at the rural sites and in the proximity of burning areas. Our N-isotope-based assessment of the variation in the relative contribution of BB-derived NH3 is further validated independently through the measurements of particulate KC, a chemical tracer of BB. Our findings underscore that BB-induced NH3 emissions in tropical monsoon environments can be much lower than previously anticipated, with important implications for future modeling studies to better constrain the climate and air quality effects of wildfires. © 2021 Author(s).
BibTeX:
@article{Chang2021,
  author = {Chang, Yunhua and Zhang, Yan-Lin and Kawichai, Sawaeng and Wang, Qian and VanDamme, Martin and Clarisse, Lieven and Prapamontol, Tippawan and Lehmann, Moritz F.},
  title = {Convergent evidence for the pervasive but limited contribution of biomass burning to atmospheric ammonia in peninsular Southeast Asia},
  journal = {Atmospheric Chemistry and Physics},
  year = {2021},
  volume = {21},
  number = {9},
  pages = {7187 – 7198},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-21-7187-2021}
}
Chen Y, Shen H, Kaiser J, Hu Y, Capps SL, Zhao S, Hakami A, Shih J-S, Pavur GK, Turner MD, Henze DK, Resler J, Nenes A, Napelenok SL, Bash JO, Fahey KM, Carmichael GR, Chai T, Clarisse L, Coheur P-F, VanDamme M and Russell AG (2021), "High-resolution hybrid inversion of IASI ammonia columns to constrain US ammonia emissions using the CMAQ adjoint model", Atmospheric Chemistry and Physics. Vol. 21(3), pp. 2067 – 2082.
Abstract: Ammonia (NH3/emissions have large impacts on air quality and nitrogen deposition, influencing human health and the well-being of sensitive ecosystems. Large uncertainties exist in the "bottom-up"NH3 emission inventories due to limited source information and a historical lack of measurements, hindering the assessment of NH3-related environmental impacts. The increasing capability of satellites to measure NH3 abundance and the development of modeling tools enable us to better constrain NH3 emission estimates at high spatial resolution. In this study, we constrain the NH3 emission estimates from the widely used 2011 National Emissions Inventory (2011 NEI) in the US using Infrared Atmospheric Sounding Interferometer NH3 column density measurements (IASI-NH3) gridded at a 36 km by 36 km horizontal resolution. With a hybrid inverse modeling approach, we use the Community Multiscale Air Quality Modeling System (CMAQ) and its multiphase adjoint model to optimize NH3 emission estimates in April, July, and October. Our optimized emission estimates suggest that the total NH3 emissions are biased low by 26 % in 2011 NEI in April with overestimation in the Midwest and underestimation in the Southern States. In July and October, the estimates from NEI agree well with the optimized emission estimates, despite a low bias in hotspot regions. Evaluation of the inversion performance using independent observations shows reduced underestimation in simulated ambient NH3 concentra tion in all 3 months and reduced underestimation in NHC 4 wet deposition in April. Implementing the optimized NH3 emission estimates improves the model performance in simulating PM2:5 concentration in the Midwest in April. The model results suggest that the estimated contribution of ammonium nitrate would be biased high in a priori NEI-based assessments. The higher emission estimates in this study also imply a higher ecological impact of nitrogen deposition originating from NH3 emissions. © 2021 Author(s).
BibTeX:
@article{Chen2021,
  author = {Chen, Yilin and Shen, Huizhong and Kaiser, Jennifer and Hu, Yongtao and Capps, Shannon L. and Zhao, Shunliu and Hakami, Amir and Shih, Jhih-Shyang and Pavur, Gertrude K. and Turner, Matthew D. and Henze, Daven K. and Resler, Jaroslav and Nenes, Athanasios and Napelenok, Sergey L. and Bash, Jesse O. and Fahey, Kathleen M. and Carmichael, Gregory R. and Chai, Tianfeng and Clarisse, Lieven and Coheur, Pierre-François and VanDamme, Martin and Russell, Armistead G.},
  title = {High-resolution hybrid inversion of IASI ammonia columns to constrain US ammonia emissions using the CMAQ adjoint model},
  journal = {Atmospheric Chemistry and Physics},
  year = {2021},
  volume = {21},
  number = {3},
  pages = {2067 – 2082},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-21-2067-2021}
}
Clarisse L, VanDamme M, Hurtmans D, Franco B, Clerbaux C and Coheur P-F (2021), "The Diel Cycle of NH3 Observed From the FY-4A Geostationary Interferometric Infrared Sounder (GIIRS)", Geophysical Research Letters. Vol. 48(14)
Abstract: Limiting excess atmospheric ammonia (NH3) is one of the great challenges for humanity in the 21st century but can only be achieved with adequate monitoring means in place. Here, we report the first NH3 measurements from the Geostationary Interferometric Infrared Sounder (GIIRS) onboard the Chinese FY-4A satellite. The instrument scans almost all of Asia 10 times per day. We show that GIIRS′ unprecedented temporal sampling can be exploited to measure diurnal and nocturnal variations of NH3 and demonstrate this on two case studies over Punjab and the North China Plain. Day–night variations are found to be almost absent in winter, but can reach a factor 2–3 in the warmer months. These case studies are very promising given the future landscape of geostationary sounders, but also show that improved knowledge on lower tropospheric air temperatures and the vertical profile of NH3 is key to better exploit their measurements. © 2021. The Authors.
BibTeX:
@article{Clarisse2021,
  author = {Clarisse, Lieven and VanDamme, Martin and Hurtmans, Daniel and Franco, Bruno and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {The Diel Cycle of NH3 Observed From the FY-4A Geostationary Interferometric Infrared Sounder (GIIRS)},
  journal = {Geophysical Research Letters},
  year = {2021},
  volume = {48},
  number = {14},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1029/2021GL093010}
}
Coheur P, Clarisse L, Hurtmans D, Franco B, VanDamme M and Clerbaux C (2021), "Atmospheric composition applications with IASI and next-generation hyperspectral infrared sounders (IASI-NG and IRS)", International Geoscience and Remote Sensing Symposium (IGARSS). Vol. 2021-July, pp. 7858 – 7859.
BibTeX:
@conference{Coheur2021,
  author = {Coheur, Pierre and Clarisse, Lieven and Hurtmans, Daniel and Franco, Bruno and VanDamme, Martin and Clerbaux, Cathy},
  title = {Atmospheric composition applications with IASI and next-generation hyperspectral infrared sounders (IASI-NG and IRS)},
  journal = {International Geoscience and Remote Sensing Symposium (IGARSS)},
  year = {2021},
  volume = {2021-July},
  pages = {7858 – 7859},
  doi = {10.1109/IGARSS47720.2021.9553663}
}
Corradini S, Guerrieri L, Brenot H, Clarisse L, Merucci L, Pardini F, Prata AJ, Realmuto VJ, Stelitano D and Theys N (2021), "Tropospheric volcanic so2 mass and flux retrievals from satellite. The etna december 2018 eruption", Remote Sensing. Vol. 13(11)
Abstract: The presence of volcanic clouds in the atmosphere affects air quality, the environment, climate, human health and aviation safety. The importance of the detection and retrieval of volcanic SO2 lies with risk mitigation as well as with the possibility of providing insights into the mechanisms that cause eruptions. Due to their intrinsic characteristics, satellite measurements have become an essential tool for volcanic monitoring. In recent years, several sensors, with different spectral, spatial and temporal resolutions, have been launched into orbit, significantly increasing the effectiveness of the estimation of the various parameters related to the state of volcanic activity. In this work, the SO2 total masses and fluxes were obtained from several satellite sounders—the geostationary (GEO) MSG-SEVIRI and the polar (LEO) Aqua/Terra-MODIS, NPP/NOAA20-VIIRS, Sentinel5p-TROPOMI, MetopA/MetopB-IASI and Aqua-AIRS—and compared to one another. As a test case, the Christmas 2018 Etna eruption was considered. The characteristics of the eruption (tropospheric with low ash content), the large amount of (simultaneously) available data and the different instrument types and SO2 columnar abundance retrieval strategies make this cross-comparison particularly relevant. Results show the higher sensitivity of TROPOMI and IASI and a general good agreement between the SO2 total masses and fluxes obtained from all the satellite instruments. The differences found are either related to inherent instrumental sensitivity or the assumed and/or calculated SO2 cloud height considered as input for the satellite retrievals. Results indicate also that, despite their low revisit time, the LEO sensors are able to provide information on SO2 flux over large time intervals. Finally, a complete error assessment on SO2 flux retrievals using SEVIRI data was realized by considering uncertainties in wind speed and SO2 abundance. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Corradini2021,
  author = {Corradini, Stefano and Guerrieri, Lorenzo and Brenot, Hugues and Clarisse, Lieven and Merucci, Luca and Pardini, Federica and Prata, Alfred J. and Realmuto, Vincent J. and Stelitano, Dario and Theys, Nicolas},
  title = {Tropospheric volcanic so2 mass and flux retrievals from satellite. The etna december 2018 eruption},
  journal = {Remote Sensing},
  year = {2021},
  volume = {13},
  number = {11},
  note = {All Open Access, Gold Open Access},
  doi = {10.3390/rs13112225}
}
Delahaye T, Armante R, Scott N, Jacquinet-Husson N, Chédin A, Crépeau L, Crevoisier C, Douet V, Perrin A, Barbe A, Boudon V, Campargue A, Coudert L, Ebert V, Flaud J-M, Gamache R, Jacquemart D, Jolly A, Kwabia Tchana F, Kyuberis A, Li G, Lyulin O, Manceron L, Mikhailenko S, Moazzen-Ahmadi N, Müller H, Naumenko O, Nikitin A, Perevalov V, Richard C, Starikova E, Tashkun S, Tyuterev V, VanderAuwera J, Vispoel B, Yachmenev A and Yurchenko S (2021), "The 2020 edition of the GEISA spectroscopic database", Journal of Molecular Spectroscopy. Vol. 380
Abstract: This paper describes the 2020 release of the GEISA database (Gestion et Etude des Informations Spectroscopiques Atmosphériques: Management and Study of Atmospheric Spectroscopic Information), developed and maintained at LMD since 1974. GEISA is the reference database for several current or planned Thermal and Short-Wave InfraRed (TIR and SWIR) space missions IASI (Infrared Atmospheric Sounding Interferometer), IASI-NG (IASI New Generation), MicroCarb (Carbon Dioxide Monitoring Mission), Merlin (MEthane Remote sensing LIdar missioN). It is actually a compilation of three databases: the “line parameters database”, the “cross-section sub-database” and the “microphysical and optical properties of atmospheric aerosols sub-database”. The new edition concerns only the line parameters dataset, with significant updates and additions implemented using the best available spectroscopic data. The GEISA-2020 line parameters database involves 58 molecules (145 isotopic species) and contains 6,746,987 entries, in the spectral range from 10−6 to 35877 cm−1. In this version, 23 molecules have been updated (with 10 new isotopic species) and 6 new molecules have been added (HONO, COFCl, CH3F, CH3I, RuO4, H2C3H2 (isomer of C3H4)) corresponding to 15 isotopic species. The compilation can be accessed through the AERIS data and services center for the atmosphere website (https://geisa.aeris-data.fr/), with the development of a powerful graphical tool and convenient searching, filtering, and plotting of data using modern technologies (PostgreSQL database, REST API, VueJS, Plotly). Based on four examples (H2O, O3, O2 and SF6), this paper also shows how the LMD in house validation algorithm SPARTE (Spectroscopic Parameters And Radiative Transfer Evaluation) helps to evaluate, correct, reject or defer the input of new spectroscopic data into GEISA and this, thanks to iterations with researchers from different communities (spectroscopy, radiative transfer). © 2021
BibTeX:
@article{Delahaye2021,
  author = {Delahaye, T. and Armante, R. and Scott, N.A. and Jacquinet-Husson, N. and Chédin, A. and Crépeau, L. and Crevoisier, C. and Douet, V. and Perrin, A. and Barbe, A. and Boudon, V. and Campargue, A. and Coudert, L.H. and Ebert, V. and Flaud, J.-M. and Gamache, R.R. and Jacquemart, D. and Jolly, A. and Kwabia Tchana, F. and Kyuberis, A. and Li, G. and Lyulin, O.M. and Manceron, L. and Mikhailenko, S. and Moazzen-Ahmadi, N. and Müller, H.S.P. and Naumenko, O.V. and Nikitin, A. and Perevalov, V.I. and Richard, C. and Starikova, E. and Tashkun, S.A. and Tyuterev, Vl.G. and VanderAuwera, J. and Vispoel, B. and Yachmenev, A. and Yurchenko, S.},
  title = {The 2020 edition of the GEISA spectroscopic database},
  journal = {Journal of Molecular Spectroscopy},
  year = {2021},
  volume = {380},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.jms.2021.111510}
}
DeLongueville H, Clarisse L, Whitburn S, Franco B, Bauduin S, Clerbaux C, Camy-Peyret C and Coheur P-F (2021), "Identification of Short and Long-Lived Atmospheric Trace Gases From IASI Space Observations", Geophysical Research Letters. Vol. 48(5)
Abstract: In recent years, major progress has been made in measuring weakly absorbing atmospheric trace gases from high spectral resolution space observations. In this paper, we apply the so-called whitening transformation on spectra of the Infrared Atmospheric Sounding Interferometer, and show that it allows removing most of the climatological background from spectra, leaving a residual that contains those spectral signatures that depart from normality. These can subsequently be attributed to changes in the abundance of trace species. This is illustrated for two diverging cases: (1) a biomass burning plume from the 2019/2020 Australian bushfires, leading to the unambiguous identification of nine reactive trace gases, including a first observation of glycolaldehyde; (2) spectra observed a decade apart, from which changes in eight long-lived halogenated substances are identified; three of them never observed before by a nadir sounder. © 2021. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{DeLongueville2021,
  author = {DeLongueville, Hélène and Clarisse, Lieven and Whitburn, Simon and Franco, Bruno and Bauduin, Sophie and Clerbaux, Cathy and Camy-Peyret, Claude and Coheur, Pierre-François},
  title = {Identification of Short and Long-Lived Atmospheric Trace Gases From IASI Space Observations},
  journal = {Geophysical Research Letters},
  year = {2021},
  volume = {48},
  number = {5},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2020GL091742}
}
Evangeliou N, Balkanski Y, Eckhardt S, Cozic A, VanDamme M, Coheur P-F, Clarisse L, Shephard MW, Cady-Pereira KE and Hauglustaine D (2021), "10-year satellite-constrained fluxes of ammonia improve performance of chemistry transport models", Atmospheric Chemistry and Physics. Vol. 21(6), pp. 4431 – 4451.
Abstract: In recent years, ammonia emissions have been continuously increasing, being almost 4 times higher than in the 20th century. Although an important species, as its use as a fertilizer sustains human living, ammonia has major consequences for both humans and the environment because of its reactive gas-phase chemistry that makes it easily convertible to particles. Despite its pronounced importance, ammonia emissions are highly uncertain in most emission inventories. However, the great development of satellite remote sensing nowadays provides the opportunity for more targeted research on constraining ammonia emissions. Here, we used satellite measurements to calculate global ammonia emissions over the period 2008 2017. Then, the calculated ammonia emissions were fed to a chemistry transport model, and ammonia concentrations were simulated for the period 2008 2017. The simulated concentrations of ammonia were compared with ground measurements from Europe, North America and Southeastern Asia, as well as with satellite measurements. The satellite-constrained ammonia emissions represent global concentrations more accurately than state-of-theart emissions. Calculated fluxes in the North China Plain were seen to be more increased after 2015, which is not due to emission changes but due to changes in sulfate emissions that resulted in less ammonia neutralization and hence in larger atmospheric loads. Emissions over Europe were also twice as much as those in traditional datasets with dominant sources being industrial and agricultural applications. Four hot-spot regions of high ammonia emissions were seen in North America, which are characterized by high agricultural activity, such as animal breeding, animal farms and agricultural practices. South America is dominated by ammonia emissions from biomass burning, which causes a strong seasonality. In Southeastern Asia, ammonia emissions from fertilizer plants in China, Pakistan, India and Indonesia are the most important, while a strong seasonality was observed with a spring and late summer peak due to rice and wheat cultivation. Measurements of ammonia surface concentrations were better reproduced with satellite-constrained emissions, such as measurements from CrIS (Cross-track Infrared Sounder). © 2021 EDP Sciences. All rights reserved.
BibTeX:
@article{Evangeliou2021,
  author = {Evangeliou, Nikolaos and Balkanski, Yves and Eckhardt, Sabine and Cozic, Anne and VanDamme, Martin and Coheur, Pierre-Francois and Clarisse, Lieven and Shephard, Mark W. and Cady-Pereira, Karen E. and Hauglustaine, DIdier},
  title = {10-year satellite-constrained fluxes of ammonia improve performance of chemistry transport models},
  journal = {Atmospheric Chemistry and Physics},
  year = {2021},
  volume = {21},
  number = {6},
  pages = {4431 – 4451},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-21-4431-2021}
}
Farji A, Aroui H and VanderAuwera J (2021), "Air-induced collisional parameters in the ν3 band of methane", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 275
Abstract: Air broadening and shift coefficients together with narrowing and first order line mixing parameters were measured for 166 lines belonging to J″ manifolds of the P (J″=2−11), Q (J″=1−12) and R (J″=0−11) branches of the ν3 band of 12CH4 near 3.3 μm. These measurements were carried out using a non-linear multispectrum least squares fitting technique. A hard collision Dicke narrowed line shape model including Rosenkranz line mixing was applied. Five high resolution Fourier transform spectra were recorded at room temperature, one at low pressure with pure methane and four at pressures up to 904 hPa with mixtures of methane and air. The measured parameters are compared with data available in the literature. © 2021 Elsevier Ltd
BibTeX:
@article{Farji2021,
  author = {Farji, A. and Aroui, H. and VanderAuwera, J.},
  title = {Air-induced collisional parameters in the ν3 band of methane},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2021},
  volume = {275},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2021.107878}
}
Franco B, Blumenstock T, Cho C, Clarisse L, Clerbaux C, Coheur P-F, De Mazière M, De Smedt I, Dorn H-P, Emmerichs T, Fuchs H, Gkatzelis G, Griffith D, Gromov S, Hannigan J, Hase F, Hohaus T, Jones N, Kerkweg A, Kiendler-Scharr A, Lutsch E, Mahieu E, Novelli A, Ortega I, Paton-Walsh C, Pommier M, Pozzer A, Reimer D, Rosanka S, Sander R, Schneider M, Strong K, Tillmann R, vanRoozendael M, Vereecken L, Vigouroux C, Wahner A and Taraborrelli D (2021), "Ubiquitous atmospheric production of organic acids mediated by cloud droplets", Nature. Vol. 593(7858), pp. 233 – 237.
Abstract: Atmospheric acidity is increasingly determined by carbon dioxide and organic acids1–3. Among the latter, formic acid facilitates the nucleation of cloud droplets4 and contributes to the acidity of clouds and rainwater1,5. At present, chemistry–climate models greatly underestimate the atmospheric burden of formic acid, because key processes related to its sources and sinks remain poorly understood2,6–9. Here we present atmospheric chamber experiments that show that formaldehyde is efficiently converted to gaseous formic acid via a multiphase pathway that involves its hydrated form, methanediol. In warm cloud droplets, methanediol undergoes fast outgassing but slow dehydration. Using a chemistry–climate model, we estimate that the gas-phase oxidation of methanediol produces up to four times more formic acid than all other known chemical sources combined. Our findings reconcile model predictions and measurements of formic acid abundance. The additional formic acid burden increases atmospheric acidity by reducing the pH of clouds and rainwater by up to 0.3. The diol mechanism presented here probably applies to other aldehydes and may help to explain the high atmospheric levels of other organic acids that affect aerosol growth and cloud evolution. © 2021, The Author(s).
BibTeX:
@article{Franco2021,
  author = {Franco, B. and Blumenstock, T. and Cho, C. and Clarisse, L. and Clerbaux, C. and Coheur, P.-F. and De Mazière, M. and De Smedt, I. and Dorn, H.-P. and Emmerichs, T. and Fuchs, H. and Gkatzelis, G. and Griffith, D.W.T. and Gromov, S. and Hannigan, J.W. and Hase, F. and Hohaus, T. and Jones, N. and Kerkweg, A. and Kiendler-Scharr, A. and Lutsch, E. and Mahieu, E. and Novelli, A. and Ortega, I. and Paton-Walsh, C. and Pommier, M. and Pozzer, A. and Reimer, D. and Rosanka, S. and Sander, R. and Schneider, M. and Strong, K. and Tillmann, R. and vanRoozendael, M. and Vereecken, L. and Vigouroux, C. and Wahner, A. and Taraborrelli, D.},
  title = {Ubiquitous atmospheric production of organic acids mediated by cloud droplets},
  journal = {Nature},
  year = {2021},
  volume = {593},
  number = {7858},
  pages = {233 – 237},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1038/s41586-021-03462-x}
}
Glorieux R, Lauzin C, Barclay A, Herman M and Moazzen-Ahmadi N (2021), "Spectroscopic study of the tunneling dynamics in N2-water observed in the O-D stretch region", Journal of Chemical Physics. Vol. 155(17)
Abstract: The O-D stretch rovibrational spectra of N2-D2O and N2-DOH were measured and analyzed. A combination band involving the in-plane N2 bending vibration was also observed. These bands were recorded using a pulsed-slit supersonic jet expansion and a mid-infrared tunable optical parametric oscillator. The spectra were analyzed by considering the feasible tunneling motions, and transitions were fitted to independent asymmetric rotors for each tunneling state. The rotational constants of the four tunneling components of N2-D2O were retrieved for the excited vibrational states. A two order of magnitude increase in the tunneling splittings is observed for the asymmetric O-D stretch (ν3 in D2O) excitation compared to the symmetric stretch (ν1 in D2O) and to the ground vibrational state. This last finding indicates that the ν3 vibrational state is likely perturbed by a combination state that includes ν1. Finally, the observation of a local perturbation in the ν3 vibrational band, affecting the positions of few rovibrational levels, provides an experimental lower limit of the dissociation energy of the complex, D0 > 120 cm-1. © 2021 Author(s).
BibTeX:
@article{Glorieux2021,
  author = {Glorieux, R. and Lauzin, C. and Barclay, A.J. and Herman, M. and Moazzen-Ahmadi, N.},
  title = {Spectroscopic study of the tunneling dynamics in N2-water observed in the O-D stretch region},
  journal = {Journal of Chemical Physics},
  year = {2021},
  volume = {155},
  number = {17},
  doi = {10.1063/5.0071732}
}
Guo X, Wang R, Pan D, Zondlo MA, Clarisse L, VanDamme M, Whitburn S, Coheur P-F, Clerbaux C, Franco B, Golston LM, Wendt L, Sun K, Tao L, Miller D, Mikoviny T, Müller M, Wisthaler A, Tevlin AG, Murphy JG, Nowak JB, Roscioli JR, Volkamer R, Kille N, Neuman JA, Eilerman SJ, Crawford JH, Yacovitch TI, Barrick JD and Scarino AJ (2021), "Validation of IASI Satellite Ammonia Observations at the Pixel Scale Using In Situ Vertical Profiles", Journal of Geophysical Research: Atmospheres. Vol. 126(9)
Abstract: Satellite ammonia (NH3) observations provide unprecedented insights into NH3 emissions, spatiotemporal variabilities and trends, but validation with in situ measurements remains lacking. Here, total columns from the Infrared Atmospheric Sounding Interferometer (IASI) were intercompared to boundary layer NH3 profiles derived from aircraft- and surface-based measurements primarily in Colorado, USA, in the summer of 2014. IASI-NH3 version 3 near real-time data set compared well to in situ derived columns (windows ±15 km around centroid, ±1 h around overpass time) with a correlation of 0.58, a slope of 0.78 ± 0.14 and an intercept of 2.1 × 1015±1.5 × 1015 molecules cm−2. Agreement degrades at larger spatiotemporal windows, consistent with the short atmospheric lifetime of NH3. We also examined IASI version 3R data, which relies on temperature retrievals from the ERA Reanalysis, and a third product generated using aircraft-measured temperature profiles. The overall agreement improves slightly for both cases, and neither is biased within their combined measurement errors. Thus, spatiotemporal averaging of IASI over large windows can be used to reduce retrieval noise. Nonetheless, sampling artifacts of airborne NH3 instruments result in significant uncertainties of the in situ-derived columns. For example, large validation differences exist between ascent and descent profiles, and the assumptions of the free tropospheric NH3 profiles used above the aircraft ceiling significantly impact the validation. Because short-lived species like NH3 largely reside within the boundary layer with complex vertical structures, more comprehensive validation is needed across a wide range of environments. More accurate and widespread in situ NH3 data sets are therefore required for improved validations of satellite products. © 2021. The Authors.
BibTeX:
@article{Guo2021,
  author = {Guo, Xuehui and Wang, Rui and Pan, Da and Zondlo, Mark A. and Clarisse, Lieven and VanDamme, Martin and Whitburn, Simon and Coheur, Pierre-François and Clerbaux, Cathy and Franco, Bruno and Golston, Levi M. and Wendt, Lars and Sun, Kang and Tao, Lei and Miller, David and Mikoviny, Tomas and Müller, Markus and Wisthaler, Armin and Tevlin, Alexandra G. and Murphy, Jennifer G. and Nowak, John B. and Roscioli, Joseph R. and Volkamer, Rainer and Kille, Natalie and Neuman, J. Andrew and Eilerman, Scott J. and Crawford, James H. and Yacovitch, Tara I. and Barrick, John D. and Scarino, Amy Jo},
  title = {Validation of IASI Satellite Ammonia Observations at the Pixel Scale Using In Situ Vertical Profiles},
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2021},
  volume = {126},
  number = {9},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1029/2020JD033475}
}
Heylen H, Devlin C, Gins W, Bissell M, Blaum K, Cheal B, Filippin L, Ruiz RFG, Godefroid M, Gorges C, Holt J, Kanellakopoulos A, Kaufmann S, Koszorús Á, König K, Malbrunot-Ettenauer S, Miyagi T, Neugart R, Neyens G, Nörtershäuser W, Sánchez R, Sommer F, Rodríguez L, Xie L, Xu Z, Yang X and Yordanov D (2021), "High-resolution laser spectroscopy of Al 27-32", Physical Review C. Vol. 103(1)
Abstract: Hyperfine spectra of Al27-32 (Z=13) have been measured at the ISOLDE-CERN facility via collinear laser spectroscopy using the 3s23p2P3/2o→3s24s2S1/2 atomic transition. For the first time, mean-square charge radii of radioactive aluminum isotopes have been determined alongside the previously unknown magnetic dipole moment of Al29 and electric quadrupole moments of Al29,30. A potentially reduced charge radius at N=19 may suggest an effect of the N=20 shell closure, which is visible in the Al chain, contrary to other isotopic chains in the sd shell. The experimental results are compared with theoretical calculations in the framework of the valence-space in-medium similarity renormalization group using multiple sets of two-and three-nucleon forces from chiral effective field theory. While the trend of experimental magnetic dipole and electric quadrupole moments is well reproduced, the absolute values are underestimated by theory, which is consistent with earlier studies. Moreover, both the scale and trend of the charge radii appear to be very sensitive to the chosen interaction. © 2021 authors.
BibTeX:
@article{Heylen2021,
  author = {Heylen, H. and Devlin, C.S. and Gins, W. and Bissell, M.L. and Blaum, K. and Cheal, B. and Filippin, L. and Ruiz, R. F. Garcia and Godefroid, M. and Gorges, C. and Holt, J.D. and Kanellakopoulos, A. and Kaufmann, S. and Koszorús, Á. and König, K. and Malbrunot-Ettenauer, S. and Miyagi, T. and Neugart, R. and Neyens, G. and Nörtershäuser, W. and Sánchez, R. and Sommer, F. and Rodríguez, L.V. and Xie, L. and Xu, Z.Y. and Yang, X.F. and Yordanov, D.T.},
  title = {High-resolution laser spectroscopy of Al 27-32},
  journal = {Physical Review C},
  year = {2021},
  volume = {103},
  number = {1},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1103/PhysRevC.103.014318}
}
Hickman JE, Andela N, Dammers E, Clarisse L, Coheur P-F, VanDamme M, Di Vittorio CA, Ossohou M, Galy-Lacaux C, Tsigaridis K and Bauer SE (2021), "Changes in biomass burning, wetland extent, or agriculture drive atmospheric NH3 trends in select African regions", Atmospheric Chemistry and Physics. Vol. 21(21), pp. 16277 – 16291.
Abstract: Atmospheric ammonia (NH3) is a precursor to fine particulate matter and a source of nitrogen (N) deposition that can adversely affect ecosystem health. The main sources of NH3 - agriculture and biomass burning - are undergoing are or expected to undergo substantial changes in Africa. Although evidence of increasing NH3 over parts of Africa has been observed, the mechanisms behind these trends are not well understood. Here we use observations of atmospheric NH3 vertical column densities (VCDs) from the Infrared Atmospheric Sounding Interferometer (IASI) along with other satellite observations of the land surface and atmosphere to evaluate how NH3 concentrations have changed over Africa from 2008 through 2018, and what has caused those changes. In West Africa NH3 VCDs are observed to increase during the late dry season, with increases of over 6 % yr-1 in Nigeria during February and March (p<0.01). These positive trends are associated with increasing burned area and CO trends during these months, likely related to agricultural preparation. Increases are also observed in the Lake Victoria basin region, where they are associated with expanding agricultural area. In contrast, NH3 VCDs declined over the Sudd wetlands in South Sudan by over 1.5 % yr-1, though not significantly (pCombining double low line0.28). Annual maxima in NH3 VCDs in South Sudan occur during February through May and are associated with the drying of temporarily flooded wetland soils, which favor emissions of NH3. The change in mean NH3 VCDs over the Sudd is strongly correlated with variation in wetland extent in the Sudd: in years when more area remained flooded during the dry season, NH3 VCDs were lower (rCombining double low line0.64, p<0.05). Relationships between biomass burning and NH3 may be observed when evaluating national-scale statistics: countries with the highest rates of increasing NH3 VCDs also had high rates of growth in CO VCDs; burned area displayed a similar pattern, though not significantly. Livestock numbers were also higher in countries with intermediate or high rates of NH3 VCD growth. Fertilizer use in Africa is currently low but growing; implementing practices that can limit NH3 losses from fertilizer as agriculture is intensified may help mitigate impacts on health and ecosystems. ©
BibTeX:
@article{Hickman2021a,
  author = {Hickman, Jonathan E. and Andela, Niels and Dammers, Enrico and Clarisse, Lieven and Coheur, Pierre-François and VanDamme, Martin and Di Vittorio, Courtney A. and Ossohou, Money and Galy-Lacaux, Corinne and Tsigaridis, Kostas and Bauer, Susanne E.},
  title = {Changes in biomass burning, wetland extent, or agriculture drive atmospheric NH3 trends in select African regions},
  journal = {Atmospheric Chemistry and Physics},
  year = {2021},
  volume = {21},
  number = {21},
  pages = {16277 – 16291},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-21-16277-2021}
}
Hickman JE, Andela N, Tsigaridis K, Galy-Lacaux C, Ossohou M, Dammers E, VanDamme M, Clarisse L and Bauer SE (2021), "Continental and Ecoregion-Specific Drivers of Atmospheric NO2 and NH3 Seasonality Over Africa Revealed by Satellite Observations", Global Biogeochemical Cycles. Vol. 35(8)
Abstract: Ammonia (NH3) and nitrogen oxides (NOx: nitrogen dioxide [NO2] + nitric oxide [NO]) play important roles in atmospheric chemistry. Throughout most of Africa, emissions of these gases are predominantly from soils and biomass burning. Here we use observations of tropospheric NO2 vertical column densities (VCDs) from the Ozone Monitoring Instrument from 2005 through 2017 and atmospheric NH3 VCDs from the Infrared Atmospheric Sounding Interferometer from 2008 through 2017 to evaluate seasonal variation of NO2 and NH3 VCDs across Africa and in seven African ecoregions. In regions where mean annual precipitation (MAP) is under 500 mm yr−1, we find that NO2 and NH3 VCDs are positively related to monthly precipitation, and where MAP is between 500 and 1,750 mm yr−1 or higher, NO2 VCDs are negatively related to monthly precipitation. In dry ecoregions, temperature and precipitation were important predictors of NH3 and NO2 VCDs, likely related to variation in soil emissions. In mesic ecoregions, monthly NO2 VCDs were strongly related to burned area, suggesting that biomass burning drives seasonality. NH3 VCDs in mesic ecoregions were positively related to both monthly temperature and monthly carbon monoxide (CO) VCDs, suggesting that a mixture of soil and biomass burning emissions influenced NH3 seasonality. In northern mesic ecoregions, monthly temperature explained most of the variance in monthly NH3 VCDs, suggesting that soil sources, including animal excreta, determined NH3 seasonality. In southern mesic ecoregions, monthly CO VCDs explained more variation in NH3 VCDs than temperature, suggesting that biomass burning may have greater influence over NH3 seasonality. © 2021. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Hickman2021,
  author = {Hickman, Jonathan E. and Andela, Niels and Tsigaridis, Kostas and Galy-Lacaux, Corinne and Ossohou, Money and Dammers, Enrico and VanDamme, Martin and Clarisse, Lieven and Bauer, Susanne E.},
  title = {Continental and Ecoregion-Specific Drivers of Atmospheric NO2 and NH3 Seasonality Over Africa Revealed by Satellite Observations},
  journal = {Global Biogeochemical Cycles},
  year = {2021},
  volume = {35},
  number = {8},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2020GB006916}
}
Ikeda K, Tanimoto H, Sugita T, Akiyoshi H, Clerbaux C and Coheur P-F (2021), "Model and Satellite Analysis of Transport of Asian Anthropogenic Pollution to the Arctic: Siberian and Pacific Pathways and Their Meteorological Controls", Journal of Geophysical Research: Atmospheres. Vol. 126(7)
Abstract: We made comprehensive analyses of long-range transport episodes of air pollutants from East Asia to the Arctic and associated meteorological conditions. While our main focus was black carbon (BC) as its transport to the Arctic has attracted great attention, carbon monoxide (CO) was also diagnosed as a species co-emitted with BC and as a tracer of long-range transport. We used satellite observations by the Infrared Atmospheric Sounding Interferometer (IASI) and a newly implemented BC tagged-tracer simulation using a global chemical transport model, GEOS-Chem. Temporal variations of IASI-CO column over the Pacific Arctic (160–200°E, 60–80°N) showed that episodic increases occurred several times in each season. For the period of 2007–2011, 11 strong events (6 in spring, 3 in autumn, and 2 in winter) caused by the long-range transport from East Asia were identified. Two transport pathways from East Asia to the Arctic were found: over Siberia and the Sea of Okhotsk, and over the North Pacific. In the pathway over Siberia and the Sea of Okhotsk, the pollutants were transported northeastward from China mainly through the Sea of Okhotsk and East Siberia. The low pressures passing from East Siberia to the Sea of Okhotsk played important roles in the transport in the lower troposphere and uplifting to the middle troposphere. In the pathway over the North Pacific, the pollutants were transported eastward from the Asian continent and subsequent northward transport took place over the North Pacific. The poleward transport occurred west of the high pressure that stayed around the Bering Sea. © 2021. The Authors.
BibTeX:
@article{Ikeda2021,
  author = {Ikeda, Kohei and Tanimoto, Hiroshi and Sugita, Takafumi and Akiyoshi, Hideharu and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Model and Satellite Analysis of Transport of Asian Anthropogenic Pollution to the Arctic: Siberian and Pacific Pathways and Their Meteorological Controls},
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2021},
  volume = {126},
  number = {7},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1029/2020JD033459}
}
Lentz C, Marcélis L, Troian-Gautier L, Robeyns K, Cauët E and Elias B (2021), "Excited-state behavior and photoinduced electron transfer of pH-sensitive Ir(III) complexes with cyclometallation (C/N–) ratios between 0/6 and 3/3", Journal of Photochemistry and Photobiology A: Chemistry. Vol. 405
Abstract: The first coordination sphere of Ir(III) 2,2′-bipyridine / 2-phenylpyridine complexes can be tuned to achieve either C– or N–chelation in ratios that range between 0/6 and 3/3. Of particular interest is the synthesis of Ir(III) complexes bearing a 2,2′-bipyridine ligand coordinated in a N,C3 pattern, leaving an exposed pyridine moiety, accessible for acid-base chemistry or coordination to a second transition metal center. The protonated forms of these “rolled-over” Ir(III) complexes were isolated in a straight-forward procedure using trifluoroacetic acid. The photophysical, photochemical and electrochemical properties of both the protonated and unprotonated Ir(III) complexes were investigated by steady-state and time-resolved spectroscopies, as well as by density functional theory calculations. The nature of the excited states was shown to depend on both the ligand coordination pattern and protonation state of the complex. In addition, the unprotonated and protonated analogues were efficiently quenched by hydroquinone and benzoquinone in acetonitrile with quenching rate constants close to the solvent diffusion limit. The results presented herein have direct implications for proton sensitive photoredox chemistry and the development of photo-acids and photo-bases. © 2020 Elsevier B.V.
BibTeX:
@article{Lentz2021,
  author = {Lentz, Cédric and Marcélis, Lionel and Troian-Gautier, Ludovic and Robeyns, Koen and Cauët, Emilie and Elias, Benjamin},
  title = {Excited-state behavior and photoinduced electron transfer of pH-sensitive Ir(III) complexes with cyclometallation (C/N–) ratios between 0/6 and 3/3},
  journal = {Journal of Photochemistry and Photobiology A: Chemistry},
  year = {2021},
  volume = {405},
  doi = {10.1016/j.jphotochem.2020.112957}
}
Loubet B, Baisnée D, Cazaunau M, Fortems-Cheiney A, Ciuraru R, Clerbaux C, Doussin J-F, Dufour G, Focsa C, George C, Gros V, Hassouna M, Jaffrezo J-L, Kammer J, Laville P, Mellouki A, Millet M, Petitprez D, Quivet E, Redon N, Sarda-Esteve R, Sauvage S, Uzu G, Villenave É and Zannoni N (2021), "Measuring Air Pollutant Concentrations and Fluxes", Agriculture and Air Quality: Investigating, Assessing and Managing. , pp. 119 – 157.
Abstract: Estimating agriculture’s contribution to air pollution and global warming is needed to understand and limit its impacts on the environment and climate. It is equally important to estimate the capacity of agricultural practices to mitigate these emissions and to characterize atmospheric deposition and the impacts of air pollutants on agroecosystems. This chapter presents methods for measuring air pollutant concentrations, their fluxes at the soil-vegetation-atmosphere interface, and emissions from livestock facilities. Methods for measuring air concentrations are described with a focus on compounds emitted from or impacting agriculture (including forests): ammonia, nitrogen oxides, pesticides, volatile organic compounds including methane, abiotic and biotic particles, and ozone. The main methods for measuring emission and deposition fluxes of air pollutants between terrestrial surfaces, especially agroecosystems, and the atmosphere are described with a specific focus on the eddy covariance method as well as on emissions from livestock buildings. Then the general principles of source apportionment methods for estimating emissions spatial variability are presented. To address the questions on atmospheric chemistry, the methods used for measuring the reactivity of atmospheric compounds are presented. Finally, an insight is given on the developments of measurement methodologies to address new compounds and improve the sensors’ sensitivity and response time as well as provide estimates of spatial variability of concentrations and fluxes at larger scales. © Springer Nature B.V. 2020.
BibTeX:
@book{Loubet2021,
  author = {Loubet, Benjamin and Baisnée, Dominique and Cazaunau, Mathieu and Fortems-Cheiney, Audrey and Ciuraru, Raluca and Clerbaux, Cathy and Doussin, Jean-François and Dufour, Gaëlle and Focsa, Cristian and George, Christian and Gros, Valérie and Hassouna, Mélynda and Jaffrezo, Jean-Luc and Kammer, Julien and Laville, Patricia and Mellouki, Abdelwahid and Millet, Maurice and Petitprez, Denis and Quivet, Etienne and Redon, Nathalie and Sarda-Esteve, Roland and Sauvage, Stéphane and Uzu, Gaëlle and Villenave, Éric and Zannoni, Nora},
  title = {Measuring Air Pollutant Concentrations and Fluxes},
  journal = {Agriculture and Air Quality: Investigating, Assessing and Managing},
  year = {2021},
  pages = {119 – 157},
  doi = {10.1007/978-94-024-2058-6_6}
}
Mahieu E, Fischer EV, Franco B, Palm M, Wizenberg T, Smale D, Clarisse L, Clerbaux C, Coheur P-F, Hannigan JW, Lutsch E, Notholt J, Cantos IP, Prignon M, Servais C and Strong K (2021), "First retrievals of peroxyacetyl nitrate (PAN) from ground-based FTIR solar spectra recorded at remote sites, comparison with model and satellite data", Elementa. Vol. 9(1)
Abstract: Peroxyacetyl nitrate (PAN) is the main tropospheric reservoir of NOx (NO þ NO2). Its lifetime can reach several months in the upper cold troposphere. This enables the long-range transport of NOx radicals, under the form of PAN, far from the regions of emission. The subsequent release of NOx through the PAN thermal decomposition leads to the efficient formation of tropospheric ozone (O3), with important consequences for tropospheric oxidative capacity and air quality. The chemical properties of PAN have stimulated the progressive development of remote-sensing products by the satellite community, and recent additions open the prospect for the production of decadal and near-global time series. These products will provide new constraints on the distribution and evolution of this key trace gas in the Earth's atmosphere, but they will also require reliable measurements for validation and characterization of performance. We present an approach that has been developed to retrieve PAN total columns from ground-based high-resolution solar absorption Fourier transform infrared (FTIR) spectra. This strategy is applied to observations recorded at remote FTIR stations of the Network for the Detection of Atmospheric Composition Change (NDACC). The resulting data sets are compared with total column time series derived from IASI (Infrared Atmospheric Sounding Interferometer) satellite observations and to a global chemical transport model. The results are discussed in terms of their overall consistency, mutual agreement, and seasonal cycles. Noticeable is the fact that the FTIR data point to substantial deficiencies in the global model simulation over high latitudes, a poorly sampled region, with an underestimation of the PAN columns during spring, at the peak of the seasonal cycle. Finally, we suggest avenues for development that should make it possible to limit intra- or intersite biases and extend the retrieval of PAN to other NDACC stations that are more affected by water vapor interferences. Copyright: © 2021 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/by/4.0/.
BibTeX:
@article{Mahieu2021,
  author = {Mahieu, Emmanuel and Fischer, Emily V. and Franco, Bruno and Palm, Mathias and Wizenberg, Tyler and Smale, Dan and Clarisse, Lieven and Clerbaux, Cathy and Coheur, Pierre-François and Hannigan, James W. and Lutsch, Erik and Notholt, Justus and Cantos, Irene Pardo and Prignon, Maxime and Servais, Christian and Strong, Kimberly},
  title = {First retrievals of peroxyacetyl nitrate (PAN) from ground-based FTIR solar spectra recorded at remote sites, comparison with model and satellite data},
  journal = {Elementa},
  year = {2021},
  volume = {9},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1525/elementa.2021.00027}
}
Maldonado-Pacheco G, García-Reynoso JA, Stremme W, Ruiz-Suárez LG, García-Yee JS, Clerbaux C and Coheur P-F (2021), "Carbon monoxide emissions assessment by using satellite and modeling data: Central Mexico case study", Atmosfera. Vol. 34(2), pp. 157 – 170.
Abstract: This paper quantifies and reduces the differences in emissions from the 2008 inventory with respect to the real ones through the use of satellite observations and modeling. Carbon monoxide column comparisons from the Infrared Atmospheric Sounding Interferometer (IASI) satellite data were made against columns obtained from the WRF-Chem model, during February 2011. The analysis was carried out at the satellite passage local time (approximately 10:00 LT) over Mexico City. The 2008 National Emissions Inventory generated by the Mexican Ministry of Environment and Natural Resources was utilized. An inversion method was applied to the modeled and observed column data. With the above, scaling factors were obtained for five regions and the concentration from the model domain boundaries, which were used to update the emissions. These were used in modeling and the result was compared with surface measurements. For Mexico City and the Metropolitan Area, a scaling factor equal to 0.43 was obtained when using the 2008 emissions inventory; for Toluca, Morelos and Puebla, a less than one factor was estimated, while for Hidalgo and the concentration from model boundaries it was close to two. The model performance was improved by an increment in the agreement index and a reduction on the mean square error when the updated CO emissions were used. © 2021 Universidad Nacional Autónoma de México, Centro de Ciencias de la Atmósfera. This is an open access article under the CC BY-NC License (http://creativecommons.org/licenses/by-nc/4.0/).
BibTeX:
@article{MaldonadoPacheco2021,
  author = {Maldonado-Pacheco, Gilberto and García-Reynoso, José Agustín and Stremme, Wolfgang and Ruiz-Suárez, Luis Gerardo and García-Yee, José Santos and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Carbon monoxide emissions assessment by using satellite and modeling data: Central Mexico case study},
  journal = {Atmosfera},
  year = {2021},
  volume = {34},
  number = {2},
  pages = {157 – 170},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.20937/ATM.52696}
}
Marais EA, Pandey AK, VanDamme M, Clarisse L, Coheur P-F, Shephard MW, Cady-Pereira KE, Misselbrook T, Zhu L, Luo G and Yu F (2021), "UK Ammonia Emissions Estimated With Satellite Observations and GEOS-Chem", Journal of Geophysical Research: Atmospheres. Vol. 126(18)
Abstract: Agricultural emissions of ammonia (NH3) impact air quality, human health, and the vitality of aquatic and terrestrial ecosystems. In the UK, there are few direct policies regulating anthropogenic NH3 emissions and development of sustainable mitigation measures necessitates reliable emissions estimates. Here, we use observations of column densities of NH3 from two space-based sensors (IASI and CrIS) with the GEOS-Chem model to derive top-down NH3 emissions for the UK at fine spatial (∼10 km) and time (monthly) scales. We focus on March-September when there is adequate spectral signal to reliably retrieve NH3. We estimate total emissions of 272 Gg from IASI and 389 Gg from CrIS. Bottom-up emissions are 27% less than IASI and 49% less than CrIS. There are also differences in seasonality. Top-down and bottom-up emissions agree on a spring April peak due to fertilizer and manure application, but there is also a comparable summer July peak in the top-down emissions that is not in the bottom-up emissions and appears to be associated with dairy cattle farming. We estimate relative errors in the top-down emissions of 11%–36% for IASI and 9%–27% for CrIS, dominated by column density retrieval errors. The bottom-up versus top-down emissions discrepancies estimated in this work impact model predictions of the environmental damage caused by NH3 emissions and warrant further investigation. © 2021. The Authors.
BibTeX:
@article{Marais2021,
  author = {Marais, Eloise A. and Pandey, Alok K. and VanDamme, Martin and Clarisse, Lieven and Coheur, Pierre-François and Shephard, Mark W. and Cady-Pereira, Karen E. and Misselbrook, Tom and Zhu, Lei and Luo, Gan and Yu, Fangqun},
  title = {UK Ammonia Emissions Estimated With Satellite Observations and GEOS-Chem},
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2021},
  volume = {126},
  number = {18},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1029/2021JD035237}
}
Papoulia A, Schiffmann S, Bieroń J, Gaigalas G, Godefroid M, Harman Z, Jönsson P, Oreshkina NS, Pyykkö P and Tupitsyn II (2021), "Ab initio electronic factors of the A and B hyperfine structure constants for the 5s25p6s P1o 1,3 states in Sn i", Physical Review A. Vol. 103(2)
Abstract: Large-scale ab initio calculations of the electronic contribution to the electric quadrupole hyperfine constant B were performed for the 5s25p6s1,3P1o excited states of neutral tin. To probe the sensitivity of B to different electron correlation effects, three sets of variational multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction calculations employing different strategies were carried out. In addition, a fourth set of calculations was based on the configuration interaction Dirac-Fock-Sturm theory. For the 5s25p6sP1o1 state, the final value of B/Q=703(50) MHz/b differs by 0.4% from the one recently used by Yordanov et al. [Commun. Phys. 3, 107 (2020)10.1038/s42005-020-0348-9] to extract the nuclear quadrupole moments Q for tin isotopes in the range Sn117-131 from collinear laser spectroscopy measurements. Efforts were made to provide a realistic theoretical uncertainty for the final B/Q value of the 5s25p6sP1o1 state based on statistical principles and on correlation with the electronic contribution to the magnetic dipole hyperfine constant A. © 2021 American Physical Society.
BibTeX:
@article{Papoulia2021,
  author = {Papoulia, Asimina and Schiffmann, Sacha and Bieroń, Jacek and Gaigalas, Gediminas and Godefroid, Michel and Harman, Zoltán and Jönsson, Per and Oreshkina, Natalia S. and Pyykkö, Pekka and Tupitsyn, Ilya I.},
  title = {Ab initio electronic factors of the A and B hyperfine structure constants for the 5s25p6s P1o 1,3 states in Sn i},
  journal = {Physical Review A},
  year = {2021},
  volume = {103},
  number = {2},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.103.022815}
}
Parracho AC, Safieddine S, Lezeaux O, Clarisse L, Whitburn S, George M, Prunet P and Clerbaux C (2021), "IASI-Derived Sea Surface Temperature Data Set for Climate Studies", Earth and Space Science. Vol. 8(5)
Abstract: Sea surface temperature (SST) is an essential climate variable, that is directly used in climate monitoring. Although satellite measurements can offer continuous global coverage, obtaining a long-term homogeneous satellite-derived SST data set suitable for climate studies based on a single instrument is still a challenge. In this work, we assess a homogeneous SST data set derived from reprocessed Infrared Atmospheric Sounding Interferometer (IASI) level-1 (L1C) radiance data. The SST is computed using Planck's Law and simple atmospheric corrections. We assess the data set using the ERA5 reanalysis and the EUMETSAT-released IASI level-2 SST product. Over the entire period, the reprocessed IASI SST shows a mean global difference with ERA5 close to zero, a mean absolute bias under 0.5°C, with a SD of difference around 0.3°C and a correlation coefficient over 0.99. In addition, the reprocessed data set shows a stable bias and SD, which is an advantage for climate studies. The interannual variability and trends were compared with other SST data sets: ERA5, Hadley Centre's SST (HadISST), and NOAA's Optimal Interpolation SST Analysis (OISSTv2). We found that the reprocessed SST data set is able to capture the patterns of interannual variability well, showing the same areas of high interannual variability (>1.5°C), including over the tropical Pacific in January corresponding to the El Niño Southern Oscillation. Although the period studied is relatively short, we demonstrate that the IASI data set reproduces the same trend patterns found in the other data sets (i.e., cooling trend in the North Atlantic, warming trend over the Mediterranean). © 2021. The Authors. Earth and Space Science published by Wiley Periodicals LLC on behalf of American Geophysical Union.
BibTeX:
@article{Parracho2021,
  author = {Parracho, Ana C. and Safieddine, Sarah and Lezeaux, Olivier and Clarisse, Lieven and Whitburn, Simon and George, Maya and Prunet, Pascal and Clerbaux, Cathy},
  title = {IASI-Derived Sea Surface Temperature Data Set for Climate Studies},
  journal = {Earth and Space Science},
  year = {2021},
  volume = {8},
  number = {5},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1029/2020EA001427}
}
Pawar PV, Ghude SD, Jena C, Móring A, Sutton MA, Kulkarni S, Mani Lal D, Surendran D, VanDamme M, Clarisse L, Coheur P-F, Liu X, Govardhan G, Xu W, Jiang J and Kumar Adhya T (2021), "Analysis of atmospheric ammonia over South and East Asia based on the MOZART-4 model and its comparison with satellite and surface observations", Atmospheric Chemistry and Physics. Vol. 21(8), pp. 6389 – 6409.
Abstract: Limited availability of atmospheric ammonia (NHspan classCombining double low line"inline-formula"3/span) observations limits our understanding of controls on its spatial and temporal variability and its interactions with the ecosystem. Here we used the Model for Ozone and Related chemical Tracers version 4 (MOZART-4) global chemistry transport model and the Hemispheric Transport of Air Pollution version 2 (HTAP-v2) emission inventory to simulate global NHspan classCombining double low line"inline-formula"3/span distribution for the year 2010. We presented a first comparison of the model with monthly averaged satellite distributions and limited ground-based observations available across South Asia. The MOZART-4 simulations over South Asia and East Asia were evaluated with the NHspan classCombining double low line"inline-formula"3/span retrievals obtained from the Infrared Atmospheric Sounding Interferometer (IASI) satellite and 69 ground-based monitoring stations for air quality across South Asia and 32 ground-based monitoring stations from the Nationwide Nitrogen Deposition Monitoring Network (NNDMN) of China. We identified the northern region of India (Indo-Gangetic Plain, IGP) as a hotspot for NHspan classCombining double low line"inline-formula"3/span in Asia, both using the model and satellite observations. In general, a close agreement was found between yearly averaged NHspan classCombining double low line"inline-formula"3/span total columns simulated by the model and IASI satellite measurements over the IGP, South Asia (span classCombining double low line"inline-formula"ir/iCombining double low line0.81/span), and the North China Plain (NCP), East Asia (span classCombining double low line"inline-formula"ir/iCombining double low line0.90/span). However, the MOZART-4-simulated NHspan classCombining double low line"inline-formula"3/span column was substantially higher over South Asia than East Asia, as compared with the IASI retrievals, which show smaller differences. Model-simulated surface NHspan classCombining double low line"inline-formula"3/span concentrations indicated smaller concentrations in all seasons than surface NHspan classCombining double low line"inline-formula"3/span measured by the ground-based observations over South and East Asia, although uncertainties remain in the available surface NHspan classCombining double low line"inline-formula"3/span measurements. Overall, the comparison of East Asia and South Asia using both MOZART-4 model and satellite observations showed smaller NHspan classCombining double low line"inline-formula"3/span columns in East Asia compared with South Asia for comparable emissions, indicating rapid dissipation of NHspan classCombining double low line"inline-formula"3/span due to secondary aerosol formation, which can be explained by larger emissions of acidic precursor gases in East Asia./. © 2021 Royal Society of Chemistry. All rights reserved.
BibTeX:
@article{Pawar2021,
  author = {Pawar, Pooja V. and Ghude, Sachin D. and Jena, Chinmay and Móring, Andrea and Sutton, Mark A. and Kulkarni, Santosh and Mani Lal, Deen and Surendran, Divya and VanDamme, Martin and Clarisse, Lieven and Coheur, Pierre-Francois and Liu, Xuejun and Govardhan, Gaurav and Xu, Wen and Jiang, Jize and Kumar Adhya, Tapan},
  title = {Analysis of atmospheric ammonia over South and East Asia based on the MOZART-4 model and its comparison with satellite and surface observations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2021},
  volume = {21},
  number = {8},
  pages = {6389 – 6409},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-21-6389-2021}
}
Richard C, Boudon V, Rizopoulos A, VanderAuwera J and Kwabia Tchana F (2021), "Line positions and intensities for the ν2/ν4 bands of 5 isotopologues of germane near 11.5 µm", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 260
Abstract: Germane is a tetrahedral molecule found in trace abundance in giant gas planets like Jupiter and Saturn. We have recently provided a database of calculated lines of the stretching fundamental bands in the 2100 cm−1 region that is of high interest for planetology (https://vamdc.icb.cnrs.fr/PHP/GeH4.php). It is now necessary to study many rovibrational levels, including the lowest ones, in order to access the hot bands and thus to improve the model of the spectral region of interest for Jupiter, especially in the framework of the ongoing Juno mission. We present here a complete analysis and modeling of line positions and intensities in the ν2/ν4 bending dyad region near 900 cm−1 for all five germane isotopologues in natural abundance. Thanks to the high symmetry of the molecule, we use the tensorial formalism and group theory methods developed in the Dijon group, that allows us to provide a set of effective Hamiltonian and dipole parameters. The present study also leads to a refined value of the Ge–H equilibrium bond length of 1.51714(25) Å. Finally, new calculated germane lines were derived and injected in the GeCaSDa database. © 2020 Elsevier Ltd
BibTeX:
@article{Richard2021,
  author = {Richard, C. and Boudon, V. and Rizopoulos, A. and VanderAuwera, J. and Kwabia Tchana, F.},
  title = {Line positions and intensities for the ν2/ν4 bands of 5 isotopologues of germane near 11.5 µm},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2021},
  volume = {260},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2020.107474}
}
Rosanka S, Franco B, Clarisse L, Coheur P-F, Pozzer A, Wahner A and Taraborrelli D (2021), "The impact of organic pollutants from Indonesian peatland fires on the tropospheric and lower stratospheric composition", Atmospheric Chemistry and Physics. Vol. 21(14), pp. 11257 – 11288.
Abstract: The particularly strong dry season in Indonesia in 2015, caused by an exceptionally strong El Niño, led to severe peatland fires resulting in high volatile organic compound (VOC) biomass burning emissions. At the same time, the developing Asian monsoon anticyclone (ASMA) and the general upward transport in the Intertropical Convergence Zone (ITCZ) efficiently transported the resulting primary and secondary pollutants to the upper troposphere and lower stratosphere (UTLS). In this study, we assess the importance of these VOC emissions for the composition of the lower troposphere and the UTLS and investigate the effect of in-cloud oxygenated VOC (OVOC) oxidation during such a strong pollution event. This is achieved by performing multiple chemistry simulations using the global atmospheric model ECHAM/MESSy (EMAC). By comparing modelled columns of the biomass burning marker hydrogen cyanide (HCN) and carbon monoxide (CO) to spaceborne measurements from the Infrared Atmospheric Sounding Interferometer (IASI), we find that EMAC properly captures the exceptional strength of the Indonesian fires. In the lower troposphere, the increase in VOC levels is higher in Indonesia compared to other biomass burning regions. This has a direct impact on the oxidation capacity, resulting in the largest regional reduction in the hydroxyl radical (OH) and nitrogen oxides (NOx). While an increase in ozone (O3) is predicted close to the peatland fires, simulated O3 decreases in eastern Indonesia due to particularly high phenol concentrations. In the ASMA and the ITCZ, the upward transport leads to elevated VOC concentrations in the lower stratosphere, which results in the reduction of OH and NOx and the increase in the hydroperoxyl radical (HO2). In addition, the degradation of VOC emissions from the Indonesian fires becomes a major source of lower stratospheric nitrate radicals (NO3), which increase by up to 20ĝ€¯%. Enhanced phenol levels in the upper troposphere result in a 20ĝ€¯% increase in the contribution of phenoxy radicals to the chemical destruction of O3, which is predicted to be as large as 40ĝ€¯% of the total chemical O3 loss in the UTLS. In the months following the fires, this loss propagates into the lower stratosphere and potentially contributes to the variability of lower stratospheric O3 observed by satellite retrievals. The Indonesian peatland fires regularly occur during El Niño years, and the largest perturbations of radical concentrations in the lower stratosphere are predicted for particularly strong El Niño years. By activating the detailed in-cloud OVOC oxidation scheme Jülich Aqueous-phase Mechanism of Organic Chemistry (JAMOC), we find that the predicted changes are dampened. Global models that neglect in-cloud OVOC oxidation tend to overestimate the impact of such extreme pollution events on the atmospheric composition. © 2021 Copernicus GmbH. All rights reserved.
BibTeX:
@article{Rosanka2021a,
  author = {Rosanka, Simon and Franco, Bruno and Clarisse, Lieven and Coheur, Pierre-François and Pozzer, Andrea and Wahner, Andreas and Taraborrelli, Domenico},
  title = {The impact of organic pollutants from Indonesian peatland fires on the tropospheric and lower stratospheric composition},
  journal = {Atmospheric Chemistry and Physics},
  year = {2021},
  volume = {21},
  number = {14},
  pages = {11257 – 11288},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-21-11257-2021}
}
Rosanka S, Sander R, Franco B, Wespes C, Wahner A and Taraborrelli D (2021), "Oxidation of low-molecular-weight organic compounds in cloud droplets: Global impact on tropospheric oxidants", Atmospheric Chemistry and Physics. Vol. 21(12), pp. 9909 – 9930.
Abstract: In liquid cloud droplets, superoxide anion (O2(aq)-) is known to quickly consume ozone (O3(aq)), which is relatively insoluble. The significance of this reaction as a tropospheric O3 sink is sensitive to the abundance of O2(aq)- and therefore to the production of its main precursor, the hydroperoxyl radical (HO2(aq)). The aqueous-phase oxidation of oxygenated volatile organic compounds (OVOCs) is the major source of HO2(aq) in cloud droplets. Hence, the lack of explicit aqueous-phase chemical kinetics in global atmospheric models leads to a general underestimation of clouds as O3 sinks. In this study, the importance of in-cloud OVOC oxidation for tropospheric composition is assessed by using the Chemistry As A Boxmodel Application (CAABA) and the global ECHAM/MESSy Atmospheric Chemistry (EMAC) model, which are both capable of explicitly representing the relevant chemical transformations. For this analysis, three different in-cloud oxidation mechanisms are employed: (1) one including the basic oxidation of SO2(aq) by O3(aq) and H2O2(aq), which thus represents the capabilities of most global models; (2) the more advanced standard EMAC mechanism, which includes inorganic chemistry and simplified degradation of methane oxidation products; and (3) the detailed in-cloud OVOC oxidation scheme Jülich Aqueous-phase Mechanism of Organic Chemistry (JAMOC). By using EMAC, the global impact of each mechanism is assessed focusing mainly on tropospheric volatile organic compounds (VOCs), HOx (HOxCombining double low lineOH+HO2), and O3. This is achieved by performing a detailed HOx and O3 budget analysis in the gas and aqueous phase. The resulting changes are evaluated against O3 and methanol (CH3OH) satellite observations from the Infrared Atmospheric Sounding Interferometer (IASI) for 2015. In general, the explicit in-cloud oxidation leads to an overall reduction in predicted OVOC levels and reduces EMAC's overestimation of some OVOCs in the tropics. The in-cloud OVOC oxidation shifts the HO2 production from the gas to the aqueous phase. As a result, the O3 budget is perturbed with scavenging being enhanced and the gas-phase chemical losses being reduced. With the simplified in-cloud chemistry, about 13Tgyr-1 of O3 is scavenged, which increases to 336Tgyr-1 when JAMOC is used. The highest O3 reduction of 12% is predicted in the upper troposphere-lower stratosphere (UTLS). These changes in the free troposphere significantly reduce the modelled tropospheric ozone columns, which are known to be generally overestimated by EMAC and other global atmospheric models. © 2021 Simon Rosanka et al.
BibTeX:
@article{Rosanka2021,
  author = {Rosanka, Simon and Sander, Rolf and Franco, Bruno and Wespes, Catherine and Wahner, Andreas and Taraborrelli, Domenico},
  title = {Oxidation of low-molecular-weight organic compounds in cloud droplets: Global impact on tropospheric oxidants},
  journal = {Atmospheric Chemistry and Physics},
  year = {2021},
  volume = {21},
  number = {12},
  pages = {9909 – 9930},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-21-9909-2021}
}
Safieddine S, George M, Clarisse L, Whitburn S and Clerbaux C (2021), "Skin temperature from IASI: Extreme events and urban heat islands monitoring", Optics InfoBase Conference Papers.
Abstract: In this work, we investigate the skin temperature product from IASI to look at local changes at the city and regional scales and to assess temperature over a period of 13 years. © 2021 The Author(s).
BibTeX:
@conference{Safieddine2021,
  author = {Safieddine, Sarah and George, Maya and Clarisse, Lieven and Whitburn, Simon and Clerbaux, Cathy},
  title = {Skin temperature from IASI: Extreme events and urban heat islands monitoring},
  journal = {Optics InfoBase Conference Papers},
  year = {2021}
}
Schiffmann S and Godefroid M (2021), "Electronic isotope shift factors for the Ir 5d76s24F9/2→(odd,J=9/2) line at 247.587 nm", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 258
Abstract: We present the theoretical calculations of the electronic isotope shift factors of the 5d76s24F9/2→(odd,J=9/2) line at 247.587 nm, that were recently used to extract nuclear mean square radii and nuclear deformations of iridium isotopes [Mukai et al. (2020)]. The fully relativistic multiconfiguration Dirac-Hartree-Fock method and the relativistic configuration interaction method were used to perform the atomic structure calculations. Additional properties such as the sharing rule, Landé g factors or phase tracking were employed to ensure an adequate description of the targeted odd level. © 2020 Elsevier Ltd
BibTeX:
@article{Schiffmann2021,
  author = {Schiffmann, Sacha and Godefroid, Michel},
  title = {Electronic isotope shift factors for the Ir 5d76s24F9/2→(odd,J=9/2) line at 247.587 nm},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2021},
  volume = {258},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2020.107332}
}
Shetye S, Van Eck S, Jorissen A, Goriely S, Siess L, Van Winckel H, Plez B, Godefroid M and Wallerstein G (2021), "S stars and s-process in the Gaia era: II. Constraining the luminosity of the third dredge-up with Tc-rich S stars", Astronomy and Astrophysics. Vol. 650
Abstract: Context. S stars are late-type giants that are transition objects between M-type stars and carbon stars on the asymptotic giant branch (AGB). They are classified into two types: intrinsic or extrinsic, based on the presence or absence of technetium (Tc). The Tc-rich or intrinsic S stars are thermally pulsing (TP-)AGB stars internally producing s-process elements (including Tc) that are brought to their surface via the third dredge-up (TDU). The Tc-poor or extrinsic S stars gained their s-process overabundances via the accretion of s-process-rich material from an AGB companion that has since turned into a dim white dwarf. Aims. Our goal is to investigate the evolutionary status of Tc-rich S stars by locating them in a Hertzsprung-Russell (HR) diagram using the results of Gaia Early Data Release 3 (EDR3). We combine the current sample of 13 Tc-rich stars with our previous studies of 10 Tc-rich stars to determine the observational onset of the TDU in the metallicity range [-0.7; 0]. We also compare our abundance determinations with dedicated AGB nucleosynthesis predictions. Methods. We derived the stellar parameters using an iterative tool that combines HERMES high-resolution spectra, accurate Gaia EDR3 parallaxes, stellar evolution models, and tailored MARCS model atmospheres for S-type stars. Using these stellar parameters, we determined the heavy-element abundances by line synthesis. Results. In the HR diagram, the intrinsic S stars are located at higher luminosities than the predicted onset of the TDU. These findings are consistent with Tc-rich S stars being genuine TP-AGB stars. The comparison of the derived s-process abundance profiles of our intrinsic S stars with the nucleosynthesis predictions provide an overall good agreement. Stars with highest [s/Fe] tend to have the highest C/O ratios. © 2021 ESO.
BibTeX:
@article{Shetye2021,
  author = {Shetye, Shreeya and Van Eck, Sophie and Jorissen, Alain and Goriely, Stephane and Siess, Lionel and Van Winckel, Hans and Plez, Bertrand and Godefroid, Michel and Wallerstein, George},
  title = {S stars and s-process in the Gaia era: II. Constraining the luminosity of the third dredge-up with Tc-rich S stars},
  journal = {Astronomy and Astrophysics},
  year = {2021},
  volume = {650},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1051/0004-6361/202040207}
}
Si R, Schiffmann S, Wang K, Chen CY and Godefroid M (2021), "Ab initio multiconfiguration Dirac-Hartree-Fock calculations of the in and Tl electron affinities and their isotope shifts", Physical Review A. Vol. 104(1)
Abstract: We report multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction calculations on the thallium (Tl) electron affinity, as well as on the excited energy levels arising from the ground configuration of Tl-. The results are compared with the available experimental values and further validated by extending the study to its homologous, lighter element, indium (In), belonging to group 13 (III.A) of the Periodic Table. The calculated electron affinities of In and Tl, 383.4 and 322.8 meV, agree with the latest measurements by within 1%. Three bound states 3P0,1,2 are confirmed in the 5s25p2 configuration of In-, while only the ground state 3P0 is bound in the 6s26p2 configuration of Tl-. The isotope shifts on the In and Tl electron affinities are also estimated. The E2 and M1 intraconfiguration radiative transition rates within 5s25p2 3P0,1,2 of In- are used to calculate the radiative lifetimes of the metastable 3P1,2 levels. © 2021 American Physical Society.
BibTeX:
@article{Si2021,
  author = {Si, Ran and Schiffmann, Sacha and Wang, Kai and Chen, Chong Yang and Godefroid, Michel},
  title = {Ab initio multiconfiguration Dirac-Hartree-Fock calculations of the in and Tl electron affinities and their isotope shifts},
  journal = {Physical Review A},
  year = {2021},
  volume = {104},
  number = {1},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.104.012802}
}
Song C, Zhang C, Wang K, Si R, Godefroid M, Jönsson P, Dang W, Zhao X, Yan J and Chen C (2021), "Extended calculations with spectroscopic accuracy: Energy levels and radiative rates for O-like ions between Ar XI and Cr XVII", Atomic Data and Nuclear Data Tables. Vol. 138
Abstract: Using the multiconfiguration Dirac–Hartree–Fock and the relativistic configuration interaction methods, a consistent set of transition energies and radiative transition data for the main states of the 2s22p4, 2s2p5, 2p6, 2s22p33s, 2s22p33p, 2s22p33d, 2s2p43s, 2s2p43p, and 2s2p43d configurations in O-like Ions between Ar XI (Z=18) and Cr XVII (Z=24) is provided. Our data set is compared with the NIST compiled values and previous calculations. The data are accurate enough for identification and deblending of new emission lines from hot astrophysical and laboratory plasmas. The amount of data of high accuracy is significantly increased for the n=3 states of several O-like ions, where experimental data are very scarce. © 2020 Elsevier Inc.
BibTeX:
@article{Song2021,
  author = {Song, C.X. and Zhang, C.Y. and Wang, K. and Si, R. and Godefroid, M. and Jönsson, P. and Dang, W. and Zhao, X.H. and Yan, J. and Chen, C.Y.},
  title = {Extended calculations with spectroscopic accuracy: Energy levels and radiative rates for O-like ions between Ar XI and Cr XVII},
  journal = {Atomic Data and Nuclear Data Tables},
  year = {2021},
  volume = {138},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.adt.2020.101377}
}
Stavrakou T, Müller J-F, Bauwens M, Doumbia T, Elguindi N, Darras S, Granier C, De Smedt I, Lerot C, vanRoozendael M, Franco B, Clarisse L, Clerbaux C, Coheur P-F, Liu Y, Wang T, Shi X, Gaubert B, Tilmes S and Brasseur G (2021), "Atmospheric impacts of COVID-19 on NOx and VOC levels over China based on TROPOMI and IASI satellite data and modeling", Atmosphere. Vol. 12(8)
Abstract: China was the first country to undergo large-scale lockdowns in response to the pandemic in early 2020 and a progressive return to normalization after April 2020. Spaceborne observations of atmospheric nitrogen dioxide (NO2) and oxygenated volatile organic compounds (OVOCs), including formaldehyde (HCHO), glyoxal (CHOCHO), and peroxyacetyl nitrate (PAN), reveal important changes over China in 2020, relative to 2019, in response to the pandemic-induced shutdown and the subsequent drop in pollutant emissions. In February, at the peak of the shutdown, the observed declines in OVOC levels were generally weaker (less than 20%) compared to the observed NO2 reductions (-40%). In May 2020, the observations reveal moderate decreases in NO2 (-15%) and PAN (-21%), small changes in CHOCHO (-3%) and HCHO (6%). Model simulations using the regional model MAGRITTEv1.1 with anthropogenic emissions accounting for the reductions due to the pandemic explain to a large extent the observed changes in lockdown-affected regions. The model results suggest that meteorological variability accounts for a minor but non-negligible part ( -5%) of the observed changes for NO2, whereas it is negligible for CHOCHO but plays a more substantial role for HCHO and PAN, especially in May. The interannual variability of biogenic and biomass burning emissions also contribute to the observed variations, explaining e.g., the important column increases of NO2 and OVOCs in February 2020, relative to 2019. These changes are well captured by the model simulations. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Stavrakou2021,
  author = {Stavrakou, Trissevgeni and Müller, Jean-François and Bauwens, Maite and Doumbia, Thierno and Elguindi, Nellie and Darras, Sabine and Granier, Claire and De Smedt, Isabelle and Lerot, Christophe and vanRoozendael, Michel and Franco, Bruno and Clarisse, Lieven and Clerbaux, Cathy and Coheur, Pierre-François and Liu, Yiming and Wang, Tao and Shi, Xiaoqin and Gaubert, Benjamin and Tilmes, Simone and Brasseur, Guy},
  title = {Atmospheric impacts of COVID-19 on NOx and VOC levels over China based on TROPOMI and IASI satellite data and modeling},
  journal = {Atmosphere},
  year = {2021},
  volume = {12},
  number = {8},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atmos12080946}
}
Sutcliffe B (2021), "Treating nuclei in molecules with quantum mechanical respect", Theoretical Chemistry Accounts. Vol. 140(3)
Abstract: An examination is made of how nuclear motion ought to be considered in solutions to the eigenvalue problem for the full Coulomb Hamiltonian and the role played by the usual clamped-nuclei electronic Hamiltonian in the construction of such solutions. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.
BibTeX:
@article{Sutcliffe2021,
  author = {Sutcliffe, Brian},
  title = {Treating nuclei in molecules with quantum mechanical respect},
  journal = {Theoretical Chemistry Accounts},
  year = {2021},
  volume = {140},
  number = {3},
  doi = {10.1007/s00214-021-02722-3}
}
Theys N, Fioletov V, Li C, De Smedt I, Lerot C, Mclinden C, Krotkov N, Griffin D, Clarisse L, Hedelt P, Loyola D, Wagner T, Kumar V, Innes A, Ribas R, Hendrick F, Vlietinck J, Brenot H and vanRoozendael M (2021), "A sulfur dioxide Covariance-Based Retrieval Algorithm (COBRA): application to TROPOMI reveals new emission sources", Atmospheric Chemistry and Physics. Vol. 21(22), pp. 16727 – 16744.
Abstract: Sensitive and accurate detection of sulfur dioxide (SO2) from space is important for monitoring and estimating global sulfur emissions. Inspired by detection methods applied in the thermal infrared, we present here a new scheme to retrieve SO2 columns from satellite observations of ultraviolet back-scattered radiances. The retrieval is based on a measurement error covariance matrix to fully represent the SO2-free radiance variability, so that the SO2 slant column density is the only retrieved parameter of the algorithm. We demonstrate this approach, named COBRA, on measurements from the TROPOspheric Monitoring Instrument (TROPOMI) aboard the Sentinel-5 Precursor (S-5P) satellite. We show that the method reduces significantly both the noise and biases present in the current TROPOMI operational DOAS SO2 retrievals. The performance of this technique is also benchmarked against that of the principal component algorithm (PCA) approach. We find that the quality of the data is similar and even slightly better with the proposed COBRA approach. The ability of the algorithm to retrieve SO2 accurately is further supported by comparison with ground-based observations. We illustrate the great sensitivity of the method with a high-resolution global SO2 map, considering 2.5 years of TROPOMI data. In addition to the known sources, we detect many new SO2 emission hotspots worldwide. For the largest sources, we use the COBRA data to estimate SO2 emission rates. Results are comparable to other recently published TROPOMI-based SO2 emissions estimates, but the associated uncertainties are significantly lower than with the operational data. Next, for a limited number of weak sources, we demonstrate the potential of our data for quantifying SO2 emissions with a detection limit of about 8 kt yr-1, a factor of 4 better than the emissions derived from the Ozone Monitoring Instrument (OMI). We anticipate that the systematic use of our TROPOMI COBRA SO2 column data set at a global scale will allow missing sources to be identified and quantified and help improve SO2 emission inventories. © 2021 Nicolas Theys et al.
BibTeX:
@article{Theys2021,
  author = {Theys, Nicolas and Fioletov, Vitali and Li, Can and De Smedt, Isabelle and Lerot, Christophe and Mclinden, Chris and Krotkov, Nickolay and Griffin, Debora and Clarisse, Lieven and Hedelt, Pascal and Loyola, Diego and Wagner, Thomas and Kumar, Vinod and Innes, Antje and Ribas, Roberto and Hendrick, François and Vlietinck, Jonas and Brenot, Hugues and vanRoozendael, Michel},
  title = {A sulfur dioxide Covariance-Based Retrieval Algorithm (COBRA): application to TROPOMI reveals new emission sources},
  journal = {Atmospheric Chemistry and Physics},
  year = {2021},
  volume = {21},
  number = {22},
  pages = {16727 – 16744},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-21-16727-2021}
}
VanDamme M, Clarisse L, Franco B, Sutton MA, Erisman JW, Wichink Kruit R, Van Zanten M, Whitburn S, Hadji-Lazaro J, Hurtmans D, Clerbaux C and Coheur P-Fo (2021), "Global, regional and national trends of atmospheric ammonia derived from a decadal (2008-2018) satellite record", Environmental Research Letters. Vol. 16(5)
Abstract: Excess atmospheric ammonia (NH3) leads to deleterious effects on biodiversity, ecosystems, air quality and health, and it is therefore essential to monitor its budget and temporal evolution. Hyperspectral infrared satellite sounders provide daily NH3 observations at global scale for over a decade. Here we use the version 3 of the Infrared Atmospheric Sounding Interferometer (IASI) NH3 dataset to derive global, regional and national trends from 2008 to 2018. We find a worldwide increase of 12.8 ± 1.3 % over this 11-year period, driven by large increases in east Asia (5.80 ± 0.61% increase per year), western and central Africa (2.58 ± 0.23 % yr-1), North America (2.40 ± 0.45 % yr-1) and western and southern Europe (1.90 ± 0.43 % yr-1). These are also seen in the Indo-Gangetic Plain, while the southwestern part of India exhibits decreasing trends. Reported national trends are analyzed in the light of changing anthropogenic and pyrogenic NH3 emissions, meteorological conditions and the impact of sulfur and nitrogen oxides emissions, which alter the atmospheric lifetime of NH3. We end with a short case study dedicated to the Netherlands and the 'Dutch Nitrogen crisis' of 2019. © 2021 The Author(s). Published by IOP Publishing Ltd.
BibTeX:
@article{VanDamme2021,
  author = {VanDamme, Martin and Clarisse, Lieven and Franco, Bruno and Sutton, Mark A and Erisman, Jan Willem and Wichink Kruit, Roy and Van Zanten, Margreet and Whitburn, Simon and Hadji-Lazaro, Juliette and Hurtmans, Daniel and Clerbaux, Cathy and Coheur, Pierre-Fran ois},
  title = {Global, regional and national trends of atmospheric ammonia derived from a decadal (2008-2018) satellite record},
  journal = {Environmental Research Letters},
  year = {2021},
  volume = {16},
  number = {5},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1088/1748-9326/abd5e0}
}
Viatte C, Petit J-E, Yamanouchi S, VanDamme M, Doucerain C, Germain-Piaulenne E, Gros V, Favez O, Clarisse L, Coheur P-F, Strong K and Clerbaux C (2021), "Ammonia and pm2.5 air pollution in paris during the 2020 covid lockdown", Atmosphere. Vol. 12(2), pp. 1 – 18.
Abstract: During the COVID-19 pandemic, the lockdown reduced anthropogenic emissions of NO2 in Paris. NO2 concentrations recorded in 2020 were the lowest they have been in the past 5 years. Despite these low-NO2 levels, Paris experienced PM2.5 pollution episodes, which were investigated here based on multi-species and multi-platform measurements. Ammonia (NH3 ) measurements over Paris, derived from a mini-DOAS (differential optical absorption spectroscopy) instrument and the Infrared Atmospheric Sounding Interferometer (IASI) satellite, revealed simultaneous enhancements during the spring PM2.5 pollution episodes. Using the IASI maps and the FLEXPART model, we show that long-range transport had a statistically significant influence on the degradation of air quality in Paris. In addition, concentrations of ammonium (NH4+ ) and PM2.5 were strongly correlated for all episodes observed in springtime 2020, suggesting that transport of NH3 drove a large component of the PM2.5 pollution over Paris. We found that NH3 was not the limiting factor for the formation of ammonium nitrate (NH4 NO3 ), and we suggest that the conversion of ammonia to ammonium may have been the essential driver. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Viatte2021,
  author = {Viatte, Camille and Petit, Jean-Eudes and Yamanouchi, Shoma and VanDamme, Martin and Doucerain, Carole and Germain-Piaulenne, Emeric and Gros, Valérie and Favez, Olivier and Clarisse, Lieven and Coheur, Pierre-Francois and Strong, Kimberly and Clerbaux, Cathy},
  title = {Ammonia and pm2.5 air pollution in paris during the 2020 covid lockdown},
  journal = {Atmosphere},
  year = {2021},
  volume = {12},
  number = {2},
  pages = {1 – 18},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atmos12020160}
}
Vohra K, Marais E, Suckra S, Kramer L, Bloss W, Sahu R, Gaur A, Tripathi S, VanDamme M, Clarisse L and Coheur PF (2021), "Long-Term trends in air quality in major cities in the UK and India: A view from space", Atmospheric Chemistry and Physics. Vol. 21(8), pp. 6275 – 6296.
Abstract: Air quality networks in cities can be costly and inconsistent and typically monitor a few pollutants. Spacebased instruments provide global coverage spanning more than a decade to determine trends in air quality, augmenting surface networks. Here we target cities in the UK (London and Birmingham) and India (Delhi and Kanpur) and use observations of nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI), ammonia (NH3) from the Infrared Atmospheric Sounding Interferometer (IASI), formaldehyde (HCHO) from OMI as a proxy for non-methane volatile organic compounds (NMVOCs), and aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) for PM2:5. We assess the skill of these products at reproducing monthly variability in surface concentrations of air pollutants where available. We find temporal consistency between column and surface NO2 in cities in the UK and India (R D0.5 0.7) and NH3 at two of three rural sites in the UK (R D0.5 0.7) but not between AOD and surface PM2:5 (R 0.4). MODIS AOD is consistent with AERONET at sites in the UK and India (R 0.8) and reproduces a significant decline in surface PM2:5 in London (2.7%a1) and Birmingham (3.7%a1) since 2009. We derive long-Term trends in the four cities for 2005 2018 from OMI and MODIS and for 2008 2018 from IASI. Trends of all pollutants are positive in Delhi, suggesting no air quality improvements there, despite the roll-out of controls on industrial and transport sectors. Kanpur, identified by the WHO as the most polluted city in the world in 2018, experiences a significant and substantial (3.1%a1) increase in PM2:5. The decline of NO2, NH3, and PM2:5 in London and Birmingham is likely due in large part to emissions controls on vehicles. Trends are significant only for NO2 and PM2:5. Reactive NMVOCs decline in Birmingham, but the trend is not significant. There is a recent (2012 2018) steep (9%a1) increase in reactive NMVOCs in London. The cause for this rapid increase is uncertain but may reflect the increased contribution of oxygenated volatile organic compounds (VOCs) from household products, the food and beverage industry, and domestic wood burning, with implications for the formation of ozone in a VOC-limited city. © 2021 Copernicus GmbH. All rights reserved.
BibTeX:
@article{Vohra2021,
  author = {Vohra, Karn and Marais, Eloise and Suckra, Shannen and Kramer, Louisa and Bloss, William and Sahu, Ravi and Gaur, Abhishek and Tripathi, Sachchida and VanDamme, Martin and Clarisse, Lieven and Coheur, Pierre F.},
  title = {Long-Term trends in air quality in major cities in the UK and India: A view from space},
  journal = {Atmospheric Chemistry and Physics},
  year = {2021},
  volume = {21},
  number = {8},
  pages = {6275 – 6296},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-21-6275-2021}
}
Wang R, Guo X, Pan D, Kelly JT, Bash JO, Sun K, Paulot F, Clarisse L, VanDamme M, Whitburn S, Coheur P-F, Clerbaux C and Zondlo MA (2021), "Monthly Patterns of Ammonia Over the Contiguous United States at 2-km Resolution", Geophysical Research Letters. Vol. 48(5)
Abstract: Monthly, high-resolution (∼2 km) ammonia (NH3) column maps from the Infrared Atmospheric Sounding Interferometer (IASI) were developed across the contiguous United States and adjacent areas. Ammonia hotspots (95th percentile of the column distribution) were highly localized with a characteristic length scale of 12 km and median area of 152 km2. Five seasonality clusters were identified with k-means++ clustering. The Midwest and eastern United States had a broad, spring maximum of NH3 (67% of hotspots in this cluster). The western United States, in contrast, showed a narrower midsummer peak (32% of hotspots). IASI spatiotemporal clustering was consistent with those from the Ammonia Monitoring Network. CMAQ and GFDL-AM3 modeled NH3 columns have some success replicating the seasonal patterns but did not capture the regional differences. The high spatial-resolution monthly NH3 maps serve as a constraint for model simulations and as a guide for the placement of future, ground-based network sites. © 2020. The Authors.
BibTeX:
@article{Wang2021,
  author = {Wang, Rui and Guo, Xuehui and Pan, Da and Kelly, James T. and Bash, Jesse O. and Sun, Kang and Paulot, Fabien and Clarisse, Lieven and VanDamme, Martin and Whitburn, Simon and Coheur, Pierre-François and Clerbaux, Cathy and Zondlo, Mark A.},
  title = {Monthly Patterns of Ammonia Over the Contiguous United States at 2-km Resolution},
  journal = {Geophysical Research Letters},
  year = {2021},
  volume = {48},
  number = {5},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2020GL090579}
}
Whitburn S, Clarisse L, Bouillon M, Safieddine S, George M, Dewitte S, DeLongueville H, Coheur P-F and Clerbaux C (2021), "Trends in spectrally resolved outgoing longwave radiation from 10 years of satellite measurements", npj Climate and Atmospheric Science. Vol. 4(1)
Abstract: In recent years, the interest has grown in satellite-derived hyperspectral radiance measurements for assessing the individual impact of climate drivers and their cascade of feedbacks on the outgoing longwave radiation (OLR). In this paper, we use 10 years (2008–2017) of reprocessed radiances from the infrared atmospheric sounding interferometer (IASI) to evaluate the linear trends in clear-sky spectrally resolved OLR (SOLR) in the range [645–2300] cm−1. Spatial inhomogeneities are observed in most of the analyzed spectral regions. These mostly reflected the natural variability of the atmospheric temperature and composition but long-term changes in greenhouse gases concentrations are also highlighted. In particular, the increase of atmospheric CO2 and CH4 led to significant negative trends in the SOLR of −0.05 to −0.3% per year in the spectral region corresponding to the ν2 and the ν3 CO2 and in the ν4 CH4 band. Most of the trends associated with the natural variability of the OLR can be related to the El Niño/Southern Oscillation activity and its teleconnections in the studied period. This is the case for the channels most affected by the temperature variations of the surface and the first layers of the atmosphere but also for the channels corresponding to the ν2 H2O and the ν3 O3 bands. © 2021, The Author(s).
BibTeX:
@article{Whitburn2021,
  author = {Whitburn, Simon and Clarisse, Lieven and Bouillon, Marie and Safieddine, Sarah and George, Maya and Dewitte, Steven and DeLongueville, Hélène and Coheur, Pierre-François and Clerbaux, Cathy},
  title = {Trends in spectrally resolved outgoing longwave radiation from 10 years of satellite measurements},
  journal = {npj Climate and Atmospheric Science},
  year = {2021},
  volume = {4},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1038/s41612-021-00205-7}
}
Yamanouchi S, Viatte C, Strong K, Lutsch E, Jones DB, Clerbaux C, VanDamme M, Clarisse L and Coheur P-F (2021), "Multiscale observations of NH3 around Toronto, Canada", Atmospheric Measurement Techniques. Vol. 14(2), pp. 905 – 921.
Abstract: Ammonia (NH3) is a major source of nitrates in the atmosphere and a major source of fine particulate matter. As such, there have been increasing efforts to measure the atmospheric abundance of NH3 and its spatial and temporal variability. In this study, long-Term measurements of NH3 derived from multiscale datasets are examined. These NH3 datasets include 16 years of total column measurements using Fourier transform infrared (FTIR) spectroscopy, 3 years of surface in situ measurements, and 10 years of total column measurements from the Infrared Atmospheric Sounding Interferometer (IASI). The datasets were used to quantify NH3 temporal variability over Toronto, Canada. The multiscale datasets were also compared to assess the representativeness of the FTIR measurements. All three time series showed positive trends in NH3 over Toronto: 3.34-0.89 %/yr from 2002 to 2018 in the FTIR columns, 8.88-5.08 %/yr from 2013 to 2017 in the surface in situ data, and 8.38-1.54 %/yr from 2008 to 2018 in the IASI columns. To assess the representative scale of the FTIR NH3 columns, correlations between the datasets were examined. The best correlation between FTIR and IASI was obtained with coincidence criteria of-25 km and-20 min, with r D 0:73 and a slope of 1.14-0.06. Additionally, FTIR column and in situ measurements were standardized and correlated. Comparison of 24 d averages and monthly averages resulted in correlation coefficients of r D 0:72 and r D 0:75, respectively, although correlation without averaging to reduce high-frequency variability led to a poorer correlation, with r D 0:39. The GEOS-Chem model, run at 22.5 resolution, was compared to FTIR and IASI to assess model performance and investigate the correlation of observational data and model output, both with local column measurements (FTIR) and measurements on a regional scale (IASI). Comparisons on a regional scale (a domain spanning 35 to 53-N and 93.75 to 63.75-W) resulted in r D 0:57 and thus a coefficient of determination, which is indicative of the predictive capacity of the model, of r2 D 0:33, but comparing a single model grid point against the FTIR resulted in a poorer correlation, with r2 D 0:13, indicating that a finer spatial resolution is needed for modeling NH3. © 2021 BMJ Publishing Group. All rights reserved.
BibTeX:
@article{Yamanouchi2021,
  author = {Yamanouchi, Shoma and Viatte, Camille and Strong, Kimberly and Lutsch, Erik and Jones, Dylan B.A. and Clerbaux, Cathy and VanDamme, Martin and Clarisse, Lieven and Coheur, Pierre-Francois},
  title = {Multiscale observations of NH3 around Toronto, Canada},
  journal = {Atmospheric Measurement Techniques},
  year = {2021},
  volume = {14},
  number = {2},
  pages = {905 – 921},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-14-905-2021}
}
Zhang CY, Wang K, Si R, Godefroid M, Jönsson P, Xiao J, Gu MF and Chen CY (2021), "Benchmarking calculations with spectroscopic accuracy of level energies and wavelengths in W LVII–W LXII tungsten ions", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 269
Abstract: Atomic properties of n=3 states of the W56+ - W61+ ions are systematically investigated through two state-of-the-art methods, namely, the second-order many-body perturbation theory, and the multi-configuration Dirac–Hartree–Fock method combined with the relativistic configuration interaction approach. The contributions of valence-valence and core-valence electron correlations, the Breit interaction, the higher-order retardation correction beyond the Breit interaction through the transverse photon interaction, and the quantum electrodynamical corrections to the excitation energies are studied in detail. The excitation energies and wavelengths obtained with the two methods agree with each other within ≈0.01%. The present results achieve spectroscopic accuracy and provide a benchmark test for various applications and other theoretical calculations of W56+ - W61+ ions. They will assist spectroscopists in their assignment and direct identification of observed lines in complex spectra. © 2021 Elsevier Ltd
BibTeX:
@article{Zhang2021,
  author = {Zhang, Chun Yu and Wang, Kai and Si, Ran and Godefroid, Michel and Jönsson, Per and Xiao, Jun and Gu, Ming Feng and Chen, Chong Yang},
  title = {Benchmarking calculations with spectroscopic accuracy of level energies and wavelengths in W LVII–W LXII tungsten ions},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2021},
  volume = {269},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2021.107650}
}
Zhang X, Del Zanna G, Wang K, Rynkun P, Jönsson P, Godefroid M, Gaigalas G, Radžiūtė L, Ma L, Si R, Xiao J, Chen Z, Yan J, Wu Y and Chen C (2021), "Benchmarking Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: Si-like Ions from Cr xi to Zn xvii", Astrophysical Journal, Supplement Series. Vol. 257(2)
Abstract: The multiconfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction methods are used to provide excitation energies, lifetimes, and radiative transition data for the 604 (699, 702, 704, 704, 704, and 699) lowest levels of the 3s 23p 2, 3s3p 3, 3s 23p3d, 3p 4, 3s3p 23d, 3s 23d 2, 3p 33d, 3s3p3d 2, 3s3d 3, 3p3d 3, 3p 23d 2, 3s 23p4s, 3s 23p4p, 3s 23p4d, 3s 23p4f, 3s3p 24s, 3s3p 24p, 3s3p 24d, 3s3p 24f, 3s 23d4s, 3s 23d4p, 3p 34s, 3p 34p, 3s3p3d4s, 3s 23p5s, and 3s 23p5p configurations in Cr xi, (Mn xii, Fe xiii, Co xiv, Ni xv, Cu xvi, and Zn xvii). Previous line identifications of Fe xiii and Ni xv in the EUV and X-ray wavelength ranges are reviewed by comprehensively comparing the MCDHF theoretical results with available experimental data. Many recent identifications of Fe xiii and Ni xv lines are confirmed, and several new identifications for these two ions are proposed. A consistent atomic data set with spectroscopic accuracy is provided for the lowest hundreds of levels for Si-like ions of iron-group elements of astrophysical interest, for which experimental values are scarce. The uncertainty estimation method suggested by Kramida, applied to the comparison of the length and velocity line strength values, is used for ranking the transition data. The correlation of the latter with the gauge dependency patterns of the line strengths is investigated. © 2021. The American Astronomical Society. All rights reserved..
BibTeX:
@article{Zhang2021a,
  author = {Zhang, X.H. and Del Zanna, G. and Wang, K. and Rynkun, P. and Jönsson, P. and Godefroid, M. and Gaigalas, G. and Radžiūtė, L. and Ma, L.H. and Si, R. and Xiao, J. and Chen, Z.B. and Yan, J. and Wu, Y. and Chen, C.Y.},
  title = {Benchmarking Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: Si-like Ions from Cr xi to Zn xvii},
  journal = {Astrophysical Journal, Supplement Series},
  year = {2021},
  volume = {257},
  number = {2},
  note = {All Open Access, Bronze Open Access},
  doi = {10.3847/1538-4365/ac2a3f}
}
Zobov N, Bertin T, VanderAuwera J, Civiš S, Knížek A, Ferus M, Ovsyannikov RI, Makhnev VY, Tennyson J and Polyansky OL (2021), "The spectrum of ammonia near 0.793 μm", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 273
Abstract: Two sets of NH3 absorption spectra covering the 0.793 μm region are recorded using two Bruker IFS 125 HR Fourier transform spectrometers. Three unapodized absorption spectra are recorded in Brussels over the range 11000−14500 cm−1 and the positions and intensities of 1114 ammonia lines observed in the 12491−12810 cm−1 region are measured using a multi-spectrum least squares fitting algorithm. 367 additional lines are identified in an ammonia absorption spectrum recorded in two steps at the J. Heyrovsky Institute of Physical Chemistry in Prague, using two different interference filters covering the 12000−12500 and 12400−13000 cm−1 ranges. The 1481 measured ammonia lines are analyzed using an empirical line list computed using variational nuclear motion calculations and ground state combination differences. Transitions are assigned to vibrational states with 4νNH stretching excitation (v1+v3=4). 278 out of the 1481 measured lines are assigned to 300 transitions and 119 upper state energy levels are derived from the frequencies of the assigned transitions. © 2021 The Authors
BibTeX:
@article{Zobov2021,
  author = {Zobov, N.F. and Bertin, T. and VanderAuwera, J. and Civiš, S. and Knížek, A. and Ferus, M. and Ovsyannikov, Roman I. and Makhnev, Vladimir Yu. and Tennyson, Jonathan and Polyansky, Oleg L.},
  title = {The spectrum of ammonia near 0.793 μm},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2021},
  volume = {273},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2021.107838}
}
Aprà E, Bylaska E, De Jong W, Govind N, Kowalski K, Straatsma T, Valiev M, Van Dam H, Alexeev Y, Anchell J, Anisimov V, Aquino F, Atta-Fynn R, Autschbach J, Bauman N, Becca J, Bernholdt D, Bhaskaran-Nair K, Bogatko S, Borowski P, Boschen J, Brabec J, Bruner A, Cauët E, Chen Y, Chuev G, Cramer C, Daily J, Deegan M, Dunning T, Dupuis M, Dyall K, Fann G, Fischer S, Fonari A, Früchtl H, Gagliardi L, Garza J, Gawande N, Ghosh S, Glaesemann K, Götz A, Hammond J, Helms V, Hermes E, Hirao K, Hirata S, Jacquelin M, Jensen L, Johnson B, Jónsson H, Kendall R, Klemm M, Kobayashi R, Konkov V, Krishnamoorthy S, Krishnan M, Lin Z, Lins R, Littlefield R, Logsdail A, Lopata K, Ma W, Marenich A, Martin Del Campo J, Mejia-Rodriguez D, Moore J, Mullin J, Nakajima T, Nascimento D, Nichols J, Nichols P, Nieplocha J, Otero-De-La-Roza A, Palmer B, Panyala A, Pirojsirikul T, Peng B, Peverati R, Pittner J, Pollack L, Richard R, Sadayappan P, Schatz G, Shelton W, Silverstein D, Smith D, Soares T, Song D, Swart M, Taylor H, Thomas G, Tipparaju V, Truhlar D, Tsemekhman K, Van Voorhis T, Vázquez-Mayagoitia A, Verma P, Villa O, Vishnu A, Vogiatzis K, Wang D, Weare J, Williamson M, Windus T, Woliński K, Wong A, Wu Q, Yang C, Yu Q, Zacharias M, Zhang Z, Zhao Y and Harrison R (2020), "NWChem: Past, present, and future", Journal of Chemical Physics. Vol. 152(18)
Abstract: Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook. © 2020 U.S. Government.
BibTeX:
@article{Apra2020,
  author = {Aprà, E. and Bylaska, E.J. and De Jong, W.A. and Govind, N. and Kowalski, K. and Straatsma, T.P. and Valiev, M. and Van Dam, H.J.J. and Alexeev, Y. and Anchell, J. and Anisimov, V. and Aquino, F.W. and Atta-Fynn, R. and Autschbach, J. and Bauman, N.P. and Becca, J.C. and Bernholdt, D.E. and Bhaskaran-Nair, K. and Bogatko, S. and Borowski, P. and Boschen, J. and Brabec, J. and Bruner, A. and Cauët, E. and Chen, Y. and Chuev, G.N. and Cramer, C.J. and Daily, J. and Deegan, M.J.O. and Dunning, T.H. and Dupuis, M. and Dyall, K.G. and Fann, G.I. and Fischer, S.A. and Fonari, A. and Früchtl, H. and Gagliardi, L. and Garza, J. and Gawande, N. and Ghosh, S. and Glaesemann, K. and Götz, A.W. and Hammond, J. and Helms, V. and Hermes, E.D. and Hirao, K. and Hirata, S. and Jacquelin, M. and Jensen, L. and Johnson, B.G. and Jónsson, H. and Kendall, R.A. and Klemm, M. and Kobayashi, R. and Konkov, V. and Krishnamoorthy, S. and Krishnan, M. and Lin, Z. and Lins, R.D. and Littlefield, R.J. and Logsdail, A.J. and Lopata, K. and Ma, W. and Marenich, A.V. and Martin Del Campo, J. and Mejia-Rodriguez, D. and Moore, J.E. and Mullin, J.M. and Nakajima, T. and Nascimento, D.R. and Nichols, J.A. and Nichols, P.J. and Nieplocha, J. and Otero-De-La-Roza, A. and Palmer, B. and Panyala, A. and Pirojsirikul, T. and Peng, B. and Peverati, R. and Pittner, J. and Pollack, L. and Richard, R.M. and Sadayappan, P. and Schatz, G.C. and Shelton, W.A. and Silverstein, D.W. and Smith, D.M.A. and Soares, T.A. and Song, D. and Swart, M. and Taylor, H.L. and Thomas, G.S. and Tipparaju, V. and Truhlar, D.G. and Tsemekhman, K. and Van Voorhis, T. and Vázquez-Mayagoitia, A. and Verma, P. and Villa, O. and Vishnu, A. and Vogiatzis, K.D. and Wang, D. and Weare, J.H. and Williamson, M.J. and Windus, T.L. and Woliński, K. and Wong, A.T. and Wu, Q. and Yang, C. and Yu, Q. and Zacharias, M. and Zhang, Z. and Zhao, Y. and Harrison, R.J.},
  title = {NWChem: Past, present, and future},
  journal = {Journal of Chemical Physics},
  year = {2020},
  volume = {152},
  number = {18},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/5.0004997}
}
Bencherif H, Bègue N, Pinheiro DK, DuPreez DJ, Cadet J-M, Lopes FJdS, Shikwambana L, Landulfo E, Vescovini T, Labuschagne C, Silva JJ, Anabor V, Coheur P-F, Mbatha N, Hadji-Lazaro J, Sivakumar V and Clerbaux C (2020), "Investigating the long-range transport of aerosol plumes following the amazon fires (August 2019): A multi-instrumental approach from ground-based and satellite observations", Remote Sensing. Vol. 12(22), pp. 1 – 18.
Abstract: Despite a number of studies on biomass burning (BB) emissions in the atmosphere, observation of the associated aerosols and pollutants requires continuous efforts. Brazil, and more broadly Latin America, is one of the most important seasonal sources of BB, particularly in the Amazon region. Uncertainty about aerosol loading in the source regions is a limiting factor in terms of understanding the role of aerosols in climate modelling. In the present work, we investigated the Amazon BB episode that occurred during August 2019 and made the international headlines, especially when the smoke plumes plunged distant cities such as São Paulo into darkness. Here, we used satellite and ground-based observations at different locations to investigate the long-range transport of aerosol plumes generated by the Amazon fires during the study period. The monitoring of BB activity was carried out using fire related pixel count from the moderate resolution imaging spectroradiometer (MODIS) onboard the Aqua and Terra platforms, while the distribution of carbon monoxide (CO) concentrations and total columns were obtained from the infrared atmospheric sounding interferometer (IASI) onboard the METOP-A and METOP-B satellites. In addition, AERONET sun-photometers as well as the MODIS instrument made aerosol optical depth (AOD) measurements over the study region. Our datasets are consistent with each other and highlight AOD and CO variations and long-range transport of the fire plume from the source regions in the Amazon basin. We used the Lagrangian transport model FLEXPART (FLEXible PARTicle) to simulate backward dispersion, which showed good agreement with satellite and ground measurements observed over the study area. The increase in Rossby wave activity during the 2019 austral winter the Southern Hemisphere may have contributed to increasing the efficiency of large-scale transport of aerosol plumes generated by the Amazon fires during the study period. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
BibTeX:
@article{Bencherif2020,
  author = {Bencherif, Hassan and Bègue, Nelson and Pinheiro, Damaris Kirsch and DuPreez, David Jean and Cadet, Jean-Maurice and Lopes, Fábio Juliano da Silva and Shikwambana, Lerato and Landulfo, Eduardo and Vescovini, Thomas and Labuschagne, Casper and Silva, Jonatan João and Anabor, Vagner and Coheur, Pierre-François and Mbatha, Nkanyiso and Hadji-Lazaro, Juliette and Sivakumar, Venkataraman and Clerbaux, Cathy},
  title = {Investigating the long-range transport of aerosol plumes following the amazon fires (August 2019): A multi-instrumental approach from ground-based and satellite observations},
  journal = {Remote Sensing},
  year = {2020},
  volume = {12},
  number = {22},
  pages = {1 – 18},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/rs12223846}
}
Bouillon M, Safieddine S, Hadji-Lazaro J, Whitburn S, Clarisse L, Doutriaux-Boucher M, Coppens D, August T, Jacquette E and Clerbaux C (2020), "Ten-year assessment of IASI radiance and temperature", Remote Sensing. Vol. 12(15)
Abstract: The Infrared Atmospheric Sounding Interferometers (IASIs) are three instruments flying on board the Metop satellites, launched in 2006 (IASI-A), 2012 (IASI-B), and 2018 (IASI-C). They measure infrared radiance from the Earth and atmosphere system, from which the atmospheric composition and temperature can be retrieved using dedicated algorithms, forming the Level 2 (L2) product. The operational near real-time processing of IASI data is conducted by the EUropean organisation for the exploitation of METeorological SATellites (EUMETSAT). It has improved over time, but due to IASI's large data flow, the whole dataset has not yet been reprocessed backwards. A necessary step that must be completed before initiating this reprocessing is to uniformize the IASI radiance record (Level 1C), which has also changed with time due to various instrumental and software modifications. In 2019, EUMETSAT released a reprocessed IASI-A 2007-2017 radiance dataset that is consistent with both the L1C product generated after 2017 and with IASI-B. First, this study aimed to assess the changes in radiance associated with this update by comparing the operational and reprocessed datasets. The differences in the brightness temperature ranged from 0.02 K at 700 cm-1 to 0.1 K at 2200 cm-1. Additionally, two major updates in 2010 and 2013 were seen to have the largest impact. Then, we investigated the effects on the retrieved temperatures due to successive upgrades to the Level 2 processing chain. We compared IASI L2 with ERA5 reanalysis temperatures. We found differences of  5-10 K at the surface and between 1 and 5 K in the atmosphere. These differences decreased abruptly after the release of the IASI L2 processor version 6 in 2014. These results suggest that it is not recommended to use the IASI inhomogeneous temperature products for trend analysis, both for temperature and trace gas trends. © 2020 by the authors.
BibTeX:
@article{Bouillon2020,
  author = {Bouillon, Marie and Safieddine, Sarah and Hadji-Lazaro, Juliette and Whitburn, Simon and Clarisse, Lieven and Doutriaux-Boucher, Marie and Coppens, Dorothée and August, Thomas and Jacquette, Elsa and Clerbaux, Cathy},
  title = {Ten-year assessment of IASI radiance and temperature},
  journal = {Remote Sensing},
  year = {2020},
  volume = {12},
  number = {15},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/RS12152393}
}
Bowen K, Hillenbrand P-M, Liévin J, Urbain X and Savin D (2020), "Astrophysically motivated laboratory measurements of deuterium reacting with isotopologues of H+3", Proceedings of the International Astronomical Union. , pp. 114 – 115.
Abstract: H2D+ and D2H+ are important chemical tracers of prestellar cores due to their pure rotational spectra that can be excited at the ∼ 20 K temperature of these environments. The use of these molecules as probes of prestellar cores requires understanding the chemistry that forms and destroys these molecules. Of the eight key reactions that have been identified (Albertsson et al. 2013), five are thought to be well understood. The remaining three are the isotope exchange reactions of atomic D with H+ 3 , H2D+, and D2H+. Semi-classical results differ from the classical Langevin calculations by an order of magnitude (Moyano et al. 2004). To resolve this discrepancy, we have carried out laboratory measurements for these three reactions. Absolute cross sections were measured using a dual-source, merged fast-beams apparatus for relative collision energies between ∼ 10 meV to ∼ 10 eV (Hillenbrand et al. 2019). A semi-empirical model was developed incorporating high level quantum mechanical ab initio calculations for the zero-point-energycorrected potential energy barrier in order to generate thermal rate coefficients for astrochemical models. Based on our studies, we find that these three reactions proceed too slowly at prestellar core temperatures to play a significant role in the deuteration of H+ 3 isotopologues. © International Astronomical Union 2020.
BibTeX:
@article{Bowen2020,
  author = {Bowen, K.P. and Hillenbrand, P.-M. and Liévin, J. and Urbain, X. and Savin, D.W.},
  title = {Astrophysically motivated laboratory measurements of deuterium reacting with isotopologues of H+3},
  journal = {Proceedings of the International Astronomical Union},
  year = {2020},
  pages = {114 – 115},
  doi = {10.1017/S1743921319006471}
}
Brenot H, Theys N, Lerot C, VanGent J, vanRoozendael M, Wilson S, Clarkson R, Clarisse L, Hyman DM, Pavolonis MJ, Biondi R, Tournigand P-Y, Corradini S, Salerno G, Durant A, Bannister D and Sievers K (2020), "Volcanic SO2 +eight SWIM 6ervice OPAS KTN Engage Catalyst funded project", SESAR Innovation Days.
Abstract: Volcanic ash and related gas cause a major risk for air traffic. To mitigate this risk and to improve situational awareness for ATM, information about the height of SO2 plume is critical. This study presents a new SWIM Yellow Profile service, so called OPAS, with the aim of providing early warnings of volcanic SO2 height from three satellite instruments (TROPOMI, IASI-A and IASI-B) with an accuracy of 1-2 km. This study describes our TROPOMI SO2 height algorithm with a validation using synthetic data, a comparison with external observations, and highlights the potential impact of flying through an SO2 cloud from the point of view of an engine constructor (Rolls-Royce) directly in relation with airlines and ATM. The SO2 height alert from TROPOMI for the recent eruption of Nishinoshima volcano in June – July 2020, illustrates the interest of OPAS service in support of volcanic SO2 plume avoidance by commercial airplanes. © 2020 IADIS. All rights reserved.
BibTeX:
@conference{Brenot2020,
  author = {Brenot, Hugues and Theys, Nicolas and Lerot, Christophe and VanGent, Jeroen and vanRoozendael, Michel and Wilson, Scott and Clarkson, Rory and Clarisse, Lieven and Hyman, Dave M. and Pavolonis, Michael J. and Biondi, Riccardo and Tournigand, Pierre-Yves and Corradini, Stefano and Salerno, Giuseppe and Durant, Adam and Bannister, Daniel and Sievers, Klaus},
  title = {Volcanic SO2 +eight SWIM 6ervice OPAS KTN Engage Catalyst funded project},
  journal = {SESAR Innovation Days},
  year = {2020}
}
Chang Y, Clarisse L, VanDamme M, Tao Y, Zou Z, Dore AJ and Collett JL (2020), "Ammonia Emissions from Mudflats of River, Lake, and Sea", ACS Earth and Space Chemistry. Vol. 4(4), pp. 614 – 619.
Abstract: Whether mudflats are an important source of atmospheric ammonia (NH3) remains an open question, despite the fact that over half of the world's population live within 3 km of surface water bodies. Here, we established three sites (lake, river, and sea) that are representative of tide-influenced mudflats across the Yangtze Delta in eastern China. Online field measurements of NH3 and auxiliary hydrometeorological parameters were simultaneously performed over a 9 month period. Surprisingly, the average NH3 concentrations measured at these locations are as low as regional background levels. No pulses of increased NH3 were found at these sites when mudflats were exposed due to receding water levels. High atmospheric NH3 concentrations are persistently associated with high temperatures, but their geographical origins have no overlap with the locations of water bodies. The potential mechanism is also discussed. Collectively, we provide the first direct observational evidence concerning mudflat as a source of NH3 © 2020 American Chemical Society.
BibTeX:
@article{Chang2020,
  author = {Chang, Yunhua and Clarisse, Lieven and VanDamme, Martin and Tao, Ye and Zou, Zhong and Dore, Anthony J. and Collett, Jeffrey L.},
  title = {Ammonia Emissions from Mudflats of River, Lake, and Sea},
  journal = {ACS Earth and Space Chemistry},
  year = {2020},
  volume = {4},
  number = {4},
  pages = {614 – 619},
  doi = {10.1021/acsearthspacechem.0c00017}
}
Deguine A, Petitprez D, Clarisse L, Guđmundsson S, Outes V, Villarosa G and Herbin H (2020), "Complex refractive index of volcanic ash aerosol in the infrared, visible, and ultraviolet", Applied Optics. Vol. 59(4), pp. 884 – 895.
Abstract: Very fine silicate-rich volcanic ash, generated by explosive volcanic eruptions, can efficiently be traced downwind with infrared satellite sounders. Their measurements can also be used to derive physical parameters, such as optical depths and effective radii. However, one of the key requirements for accurate retrievals is a good knowledge of the complex refractive index (CRI) of the ash under investigation. In the past, the vast majority of the studies used the CRIs from Pollack et al. [Icarus 19, 372 (1973)], which are based on measurements of thin slices of volcanic rock, and therefore are not representative for airborne volcanic ash particles. Here, we report measurements of the CRI of volcanic ash in suspension, generated from samples collected from recent high-impact eruptions in Chile (Puyehue-Cordón Caulle, Calbuco, and Chaitén), Iceland (Eyjafjallajökull and Grímsvötn), and Italy (Etna). The samples cover a wide range of SiO2 content (46% to 76%) as confirmed by an X-ray fluorescence analysis. In the experimental setup, volcanic ash was suspended in nitrogen through mechanical agitation. Extinction spectra were recorded in the infrared, visible, and ultraviolet spectral regions. The particle size distribution within the airflow was also recorded. An iterative algorithm allowed us to obtain fully consistent CRIs for the six samples, compatible with the observed extinction spectra and the Kramers–Krönig relations. While a good agreement is found with other recently reported CRIs in the UV/Vis, larger differences are found in the longwave infrared spectral region. © 2020 Optical Society of America.
BibTeX:
@article{Deguine2020,
  author = {Deguine, Alexandre and Petitprez, Denis and Clarisse, Lieven and Guđmundsson, Snævarr and Outes, Valeria and Villarosa, Gustavo and Herbin, Hervé},
  title = {Complex refractive index of volcanic ash aerosol in the infrared, visible, and ultraviolet},
  journal = {Applied Optics},
  year = {2020},
  volume = {59},
  number = {4},
  pages = {884 – 895},
  doi = {10.1364/AO.59.000884}
}
DuPreez DJ, Bencherif H, Bègue N, Clarisse L, Hoffman RF and Wright CY (2020), "Investigating the large-scale transport of a volcanic plume and the impact on a secondary site", Atmosphere. Vol. 11(5)
Abstract: Volcanic plumes can be transported across vast distances and can have an impact on solar ultraviolet radiation (UVR) reaching the surface due to the scattering and absorption caused by aerosols. The dispersion of the volcanic plume from the Puyehue-Cordon Caulle volcanic complex (PCCVC) eruption was investigated to determine the effect on aerosol loading at Cape Point, South Africa. The eruption occurred on 4 June 2011 and resulted in a plume reaching a height of between 9 and 12 km and was dispersed across the Southern Hemisphere. Satellite sulphur dioxide (SO2) observations and a dispersion model showed low concentrations of SO2 at the secondary site. However, satellite observations of volcanic ash and ground-based aerosol measurements did show increases between 10 and 20 June 2011 at the secondary site. Furthermore, there was good agreement with the dispersion model results and observations from satellites with most of the plume located between latitudes 40°-60° South. © 2020 by the authors.
BibTeX:
@article{DuPreez2020,
  author = {DuPreez, David Jean and Bencherif, Hassan and Bègue, Nelson and Clarisse, Lieven and Hoffman, Rebecca F. and Wright, Caradee Yael},
  title = {Investigating the large-scale transport of a volcanic plume and the impact on a secondary site},
  journal = {Atmosphere},
  year = {2020},
  volume = {11},
  number = {5},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atmos11050548}
}
Elias B, Cerfontaine S, Troian-Gautier L, Wehlin SAM, Loiseau F and Cauët E (2020), "Tuning the excited-state deactivation pathways of dinuclear ruthenium(ii) 2,2′-bipyridine complexes through bridging ligand design", Dalton Transactions. Vol. 49(24), pp. 8096 – 8106.
Abstract: A detailed photophysical investigation of two dinuclear ruthenium(ii) complexes is reported. The two metallic centers were coordinated to a bis-2,2′-bipyridine bridging ligand, connected either through the para (Lp, Dp) or the meta position (Lm, Dm). The results obtained herein were compared to the prototypical [Ru(bpy)3]2+ parent compound. The formation of dinuclear complexes was accompanied by the expected increase in molar absorption coefficients, i.e. 12 000 M-1 cm-1, 17 000 M-1 cm-1, and 22 000 M-1 cm-1 at the lowest energy MLCTmax transition for [Ru(bpy)3]2+, Dm and Dp respectively. The Lp bridging ligand resulted in a ruthenium(ii) dinuclear complex that absorbed more visible light, and had a longer-lived and more delocalized excited-state compared to a complex with the Lm bridging ligand. Variable temperature measurements provided valuable information about activation energies to the uppermost 3MLCT state and the metal-centered (3MC) state, often accompanied by irreversible ligand-loss chemistry. At 298 K, 48% of [Ru(bpy)3]2+∗ excited-state underwent deactivation through the 3MC state, whereas this deactivation pathway remained practically unpopulated (<0.5%) in both dinuclear complexes. This journal is © The Royal Society of Chemistry.
BibTeX:
@article{Elias2020,
  author = {Elias, Benjamin and Cerfontaine, Simon and Troian-Gautier, Ludovic and Wehlin, Sara A. M. and Loiseau, Frédérique and Cauët, Emilie},
  title = {Tuning the excited-state deactivation pathways of dinuclear ruthenium(ii) 2,2′-bipyridine complexes through bridging ligand design},
  journal = {Dalton Transactions},
  year = {2020},
  volume = {49},
  number = {24},
  pages = {8096 – 8106},
  doi = {10.1039/d0dt01216e}
}
Fortems-Cheiney A, Dufour G, Dufossé K, Couvidat F, Gilliot J-M, Siour G, Beekmann M, Foret G, Meleux F, Clarisse L, Coheur P-F, VanDamme M, Clerbaux C and Génermont S (2020), "Do alternative inventories converge on the spatiotemporal representation of spring ammonia emissions in France", Atmospheric Chemistry and Physics. Vol. 20(21), pp. 13481 – 13495.
Abstract: Agriculture is the main source of ammonia (NH3) in France, an important gaseous precursor of atmospheric particulate matter (PM). National and global emission inventories are known to have difficulty representing the large spatial and temporal variability inherent to atmospheric NH3. In this study, we compare NH3 emissions in France during spring 2011 from one reference inventory, the TNO inventory, and two alternative inventories that account in different manners for both the spatial and temporal variabilities of the emissions: (i) the NH3SAT satellite-derived inventory based on IASI NH3 columns and (ii) the CADASTRE-CIT inventory that combines NH3 emissions due to nitrogen fertilization calculated with the mechanistic model VOLT'AIR on the database of the CADASTRE_NH3 framework and other source emissions from the CITEPA. The total spring budgets, from March to May 2011, at the national level are higher when calculated with both alternative inventories than with the reference, the difference being more marked with CADASTRE-CIT. NH3SAT and CADASTRE-CIT inventories both yield to large NH3 spring emissions due to fertilization on soils with high pH in the northeastern part of France (65 and 135 ktNH3, respectively, vs. 48 ktNH3 for TNO-GEN), while soil properties are not accounted for by the TNO-GEN methodology. For the other parts of France, the differences are smaller. The timing of fertilization and associated ammonia emissions is closely related to the nitrogen requirements and hence the phenological stage of the crops, and therefore to the crop year's specific weather conditions. Maximum emissions are observed in March for 2011 for some regions for both alternative inventories, while April is the period with maximum emissions for the reference inventory regardless of the region or the year. Comparing the inventories at finer temporal resolutions, typically at daily scale, large differences are found. The convergence of alternative, independent and complementary methods on the spatiotemporal representation of the spring NH3 emissions, particularly over areas where the contribution of mineral fertilizer spreading to the spring budget is strong, encourages further developments in both prospective complementary directions, as this will help improve national NH3 emission inventories. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
BibTeX:
@article{FortemsCheiney2020,
  author = {Fortems-Cheiney, Audrey and Dufour, Gaelle and Dufossé, Karine and Couvidat, Florian and Gilliot, Jean-Marc and Siour, Guillaume and Beekmann, Matthias and Foret, Gilles and Meleux, Frederik and Clarisse, Lieven and Coheur, Pierre-Francois and VanDamme, Martin and Clerbaux, Cathy and Génermont, Sophie},
  title = {Do alternative inventories converge on the spatiotemporal representation of spring ammonia emissions in France},
  journal = {Atmospheric Chemistry and Physics},
  year = {2020},
  volume = {20},
  number = {21},
  pages = {13481 – 13495},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-20-13481-2020}
}
Franco B, Clarisse L, Stavrakou T, Müller J-F, Taraborrelli D, Hadji-Lazaro J, Hannigan J, Hase F, Hurtmans D, Jones N, Lutsch E, Mahieu E, Ortega I, Schneider M, Strong K, Vigouroux C, Clerbaux C and Coheur P-F (2020), "Spaceborne Measurements of Formic and Acetic Acids: A Global View of the Regional Sources", Geophysical Research Letters. Vol. 47(4)
Abstract: Formic (HCOOH) and acetic acids (CH3COOH) are the most abundant carboxylic acids in the Earth's atmosphere and key compounds to aqueous-phase chemistry. Here we present the first distributions of CH3COOH retrieved from the 2007–2018 satellite observations of the nadir-looking infrared atmospheric sounding interferometer (IASI), using a neural network-based retrieval approach. A joint analysis with the IASI HCOOH product reveals that the two species exhibit similar distributions, seasonality, and atmospheric burden, pointing to major common sources. We show that their abundance is highly correlated to isoprene and monoterpenes emissions, as well as to biomass burning. Over Africa, evidence is provided that residual smoldering combustion might be a major driver of the HCOOH and CH3COOH seasonality. Earlier seasonal enhancement of HCOOH at Northern Hemisphere middle and high latitudes and late seasonal secondary peaks of CH3COOH in the tropics suggest that sources and production pathways specific to each species are also at play. ©2020. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Franco2020,
  author = {Franco, B. and Clarisse, L. and Stavrakou, T. and Müller, J.-F. and Taraborrelli, D. and Hadji-Lazaro, J. and Hannigan, J.W. and Hase, F. and Hurtmans, D. and Jones, N. and Lutsch, E. and Mahieu, E. and Ortega, I. and Schneider, M. and Strong, K. and Vigouroux, C. and Clerbaux, C. and Coheur, P.-F.},
  title = {Spaceborne Measurements of Formic and Acetic Acids: A Global View of the Regional Sources},
  journal = {Geophysical Research Letters},
  year = {2020},
  volume = {47},
  number = {4},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2019GL086239}
}
Friedrich M, Beutner E, Reuvers H, Smeekes S, Urbain J-P, Bader W, Franco B, Lejeune B and Mahieu E (2020), "A statistical analysis of time trends in atmospheric ethane", Climatic Change. Vol. 162(1), pp. 105 – 125.
Abstract: Ethane is the most abundant non-methane hydrocarbon in the Earth’s atmosphere and an important precursor of tropospheric ozone through various chemical pathways. Ethane is also an indirect greenhouse gas (global warming potential), influencing the atmospheric lifetime of methane through the consumption of the hydroxyl radical (OH). Understanding the development of trends and identifying trend reversals in atmospheric ethane is therefore crucial. Our dataset consists of four series of daily ethane columns. As with many other decadal time series, our data are characterized by autocorrelation, heteroskedasticity, and seasonal effects. Additionally, missing observations due to instrument failure or unfavorable measurement conditions are common in such series. The goal of this paper is therefore to analyze trends in atmospheric ethane with statistical tools that correctly address these data features. We present selected methods designed for the analysis of time trends and trend reversals. We consider bootstrap inference on broken linear trends and smoothly varying nonlinear trends. In particular, for the broken trend model, we propose a bootstrap method for inference on the break location and the corresponding changes in slope. For the smooth trend model, we construct simultaneous confidence bands around the nonparametrically estimated trend. Our autoregressive wild bootstrap approach, combined with a seasonal filter, is able to handle all issues mentioned above (we provide R code for all proposed methods on https://www.stephansmeekes.nl/code.). © 2020, The Author(s).
BibTeX:
@article{Friedrich2020,
  author = {Friedrich, Marina and Beutner, Eric and Reuvers, Hanno and Smeekes, Stephan and Urbain, Jean-Pierre and Bader, Whitney and Franco, Bruno and Lejeune, Bernard and Mahieu, Emmanuel},
  title = {A statistical analysis of time trends in atmospheric ethane},
  journal = {Climatic Change},
  year = {2020},
  volume = {162},
  number = {1},
  pages = {105 – 125},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1007/s10584-020-02806-2}
}
Gamrath S, Godefroid M, Palmeri P, Quinet P and Wang K (2020), "Spectral line list of potential cosmochronological interest deduced from new calculations of radiative transition rates in singly ionized thorium (Th II)", Monthly Notices of the Royal Astronomical Society. Vol. 496(4), pp. 4507 – 4516.
Abstract: In this work, we report a list of 91 strong Th II spectral lines in the visible wavelength region that could be used as cosmochronometers in future investigations to determine stellar ages from thorium radioactive decay. This list was established on the basis of a pseudo-relativistic Hartree-Fock model including core-polarization corrections (HFR+CPOL) allowing us to compute the corresponding radiative decay parameters, the latter being found to be in good overall agreement with the most accurate experimental data when available. Besides this semi-empirical approach, the fully relativistic ab initio multiconfiguration Dirac-Hartree-Fock (MCDHF) method was attempted, showing large discrepancies with both the present HFR+CPOL and the most recent experimental oscillator strengths, although the calculated wavelengths from theoretical energy levels agreed with observed spectral line wavelengths within 2.4 per cent. © 2020 The Author(s).
BibTeX:
@article{Gamrath2020,
  author = {Gamrath, S. and Godefroid, M.R. and Palmeri, P. and Quinet, P. and Wang, K.},
  title = {Spectral line list of potential cosmochronological interest deduced from new calculations of radiative transition rates in singly ionized thorium (Th II)},
  journal = {Monthly Notices of the Royal Astronomical Society},
  year = {2020},
  volume = {496},
  number = {4},
  pages = {4507 – 4516},
  doi = {10.1093/mnras/staa1740}
}
Jiang J, Du Z, Liévin J and Field RW (2020), "One-colour (∼220 nm) resonance-enhanced (S1 − S0) multi-photon dissociation of acetylene: probe of the C2 A 1 Π u − X 1 Σ+ g band by frequency-modulation spectroscopy", Molecular Physics. Vol. 118(15)
Abstract: In a recent paper, we demonstrated that one-colour (∼220 nm), resonance-enhanced (S (Formula presented.) S (Formula presented.)), photodissociation of acetylene generates strong (Formula presented.) Swan band ((Formula presented.)) and (Formula presented.) Deslandres-d'Azambuja band ((Formula presented.)) fluorescence, and long-lived (>3 µs) fluorescence from an electronically-excited (Formula presented.) H (Formula presented.) species. It was not known whether the (Formula presented.) and (Formula presented.) states are also directly populated in this process. In this work, multiple vibration-rotation transitions between the (Formula presented.) -state v = 2 and the X-state v = 0 level are examined by time-resolved frequency-modulation (FM) spectroscopy. The photolysis laser wavelength is tuned into resonance at the one-photon level with S (Formula presented.) S (Formula presented.) transitions that populate individual rotational levels of the S (Formula presented.) -conformer (Formula presented.), (Formula presented.), and (Formula presented.) vibrational states. By comparing the phase of the FM signals from the (Formula presented.) transitions with that from the Rb D (Formula presented.) -line absorption transition, we determine that, for all of the probed A−X transitions, the X-state level is more populated than the A-state level. We propose that the acetylene S (Formula presented.) level is excited by the second photon to an acetylene dissociation precursor state, which undergoes sequential C-H bond-breaking to produce the (Formula presented.) state. The dissociation precursor is assigned as the (Formula presented.) valence state, which correlates to a doubly-excited configuration, (Formula presented.), at linear geometry. Based on the rotational distributions of the (Formula presented.) -state fragments, we believe that at least one of the transition states involved in the photolysis via S (Formula presented.) has a larger CC-H bend-angle for the departing H-atom than that involved in the S (Formula presented.) and (Formula presented.) photolysis. © 2020 Informa UK Limited, trading as Taylor & Francis Group.
BibTeX:
@article{Jiang2020,
  author = {Jiang, Jun and Du, Zhenhui and Liévin, Jacques and Field, Robert W.},
  title = {One-colour (∼220 nm) resonance-enhanced (S1 − S0) multi-photon dissociation of acetylene: probe of the C2 A 1 Π u − X 1 Σ+ g band by frequency-modulation spectroscopy},
  journal = {Molecular Physics},
  year = {2020},
  volume = {118},
  number = {15},
  note = {All Open Access, Green Open Access},
  doi = {10.1080/00268976.2020.1724340}
}
Kas M, Liévin J, Vaeck N and Loreau J (2020), "Cold collisions of C2- with Li and Rb atoms in hybrid traps", Journal of Physics: Conference Series. Vol. 1412(6)
Abstract: We present a theoretical investigation of reactive and non-reactive collisions of Li and Rb atoms with C2- molecular anions at low temperatures in the context of sympathetic cooling in hybrid trap experiments. Based on accurate potential energy surfaces for the singlet and triplet states of the Li-C2- and Rb-C2- systems, we show that the associative electronic detachment reaction is inefficient but that it occurs with a large rate for collisions involving excited states of either Li/Rb or C2-. We also investigate rotationally inelastic collisions in order to explore the cooling of the translational and rotational degrees of freedom of C2- in hybrid ion-atom traps. The effect of micromotion is taken into account by considering Tsallis distributions of collision energies. We show that the translational cooling occurs much more rapidly than rotational cooling and that the presence of excited atoms leads to losses of anions on a timescale comparable to that of rotational cooling. © Published under licence by IOP Publishing Ltd.
BibTeX:
@conference{Kas2020,
  author = {Kas, Milaim and Liévin, Jacques and Vaeck, Nathalie and Loreau, Jérôme},
  title = {Cold collisions of C2- with Li and Rb atoms in hybrid traps},
  journal = {Journal of Physics: Conference Series},
  year = {2020},
  volume = {1412},
  number = {6},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1088/1742-6596/1412/6/062003}
}
Kuttippurath J, Singh A, Dash S, Mallick N, Clerbaux C, VanDamme M, Clarisse L, Coheur P-F, Raj S, Abbhishek K and Varikoden H (2020), "Record high levels of atmospheric ammonia over India: Spatial and temporal analyses", Science of the Total Environment. Vol. 740
Abstract: Atmospheric ammonia (NH3) is an alkaline gas and a prominent constituent of the nitrogen cycle that adversely affects ecosystems at higher concentrations. It is a pollutant, which influences all three spheres such as haze formation in the atmosphere, soil acidification in the lithosphere, and eutrophication in water bodies. Atmospheric NH3 reacts with sulfur (SOx) and nitrogen (NOx) oxides to form aerosols, which eventually affect human health and climate. Here, we present the seasonal and inter-annual variability of atmospheric NH3 over India in 2008–2016 using the IASI (Infrared Atmospheric Sounding Interferometer) satellite observations. We find that Indo-Gangetic Plains (IGP) is one of the largest and rapidly growing NH3 hotspots of the world, with a growth rate of +1.2% yr−1 in summer (June–August: Kharif season), due to intense agricultural activities and presence of many fertilizer industries there. However, our analyses show insignificant decreasing trends in annual NH3 of about −0.8% yr−1 in all India, about −0.4% yr−1 in IGP, and −1.0% yr−1 in the rest of India. Ammonia is positively correlated with total fertilizer consumption (r = 0.75) and temperature (r = 0.5) since high temperature favors volatilization, and is anti-correlated with total precipitation (r = from −0.2, but −0.8 in the Rabi season: October–February) as wet deposition helps removal of atmospheric NH3. This study, henceforth, suggests the need for better fertilization practices and viable strategies to curb emissions, to alleviate the adverse health effects and negative impacts on the ecosystem in the region. On the other hand, the overall decreasing trend in atmospheric NH3 over India shows the positive actions, and commitment to the national missions and action plans to reduce atmospheric pollution and changes in climate. © 2020 Elsevier B.V.
BibTeX:
@article{Kuttippurath2020,
  author = {Kuttippurath, J. and Singh, A. and Dash, S.P. and Mallick, N. and Clerbaux, C. and VanDamme, M. and Clarisse, L. and Coheur, P.-F. and Raj, S. and Abbhishek, K. and Varikoden, H.},
  title = {Record high levels of atmospheric ammonia over India: Spatial and temporal analyses},
  journal = {Science of the Total Environment},
  year = {2020},
  volume = {740},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.scitotenv.2020.139986}
}
Lauzin C, Imbreckx A, Foldes T, Vanfleteren T, Moazzen-Ahmadi N and Herman M (2020), "High-resolution spectroscopic study of the H2O–CO2 van der Waals complex in the 2OH overtone range", Molecular Physics. Vol. 118(11)
Abstract: The jet-cooled spectrum ((Formula presented.) K) of the H (Formula presented.) O–CO (Formula presented.) van der Waals complex has been recorded in the 1.4 μm region by cavity ring-down spectroscopy. Two b-type vibrational bands have been observed and analysed. The rotational assignment has been achieved using a different asymmetric rotor Hamiltonian for each nuclear spin species, accounting for the internal rotation of the H (Formula presented.) O and CO (Formula presented.) units. The band at 7247 cm (Formula presented.) is assigned to (101) in terms of the ((Formula presented.)) vibrational quantum number of the H (Formula presented.) O monomer. The band at 7238 cm (Formula presented.) is assigned to (200) + an intermolecular mode ((Formula presented.)) excited in the complex. Vibration-rotation constants are provided for the excited states. The symmetry of the wavefunction, the effect of vibrational excitation on the tunnelling dynamics and the vibrational assignment are discussed. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.
BibTeX:
@article{Lauzin2020,
  author = {Lauzin, C. and Imbreckx, A.C. and Foldes, T. and Vanfleteren, T. and Moazzen-Ahmadi, N. and Herman, M.},
  title = {High-resolution spectroscopic study of the H2O–CO2 van der Waals complex in the 2OH overtone range},
  journal = {Molecular Physics},
  year = {2020},
  volume = {118},
  number = {11},
  doi = {10.1080/00268976.2019.1706776}
}
Leifer I, Melton C, Tratt DM, Buckland KN, Chang CS, Clarisse L, Franklin M, Hall JL, Brian Leen J, Lundquist T, VanDamme M, Vigil S and Whitburn S (2020), "Estimating exposure to hydrogen sulfide from animal husbandry operations using satellite ammonia as a proxy: Methodology demonstration", Science of the Total Environment. Vol. 709
Abstract: Husbandry trace gases that have climate change implications such as carbon dioxide (CO2), methane (CH4) and ammonia (NH3) can be quantified through remote sensing; however, many husbandry gases with health implications such as hydrogen sulfide (H2S), cannot. This pilot study demonstrates an approach to derive H2S concentrations by coupling in situ and remote sensing data. Using AMOG (AutoMObile trace Gas) Surveyor, a mobile air quality and meteorology laboratory, we measured in situ concentrations of CH4, CO2, NH3, H2S, and wind at a southern California university research dairy. Emissions were 0.13, 1.93, 0.022 and 0.0064 Gg yr−1; emission factors (EF) were 422, 6333, 74, and 21 kg cow−1 yr−1, respectively, for the 306 head herd. Contributing to these strong EF were spillway emissions from a grate between the main cowshed and the waste lagoon identified in airborne remote sensing data acquired by the hyperspectral thermal infrared imager, Mako. NH3 emissions from the Chino Dairy Complex, also in southern California, were calculated from Infrared Atmospheric Sounding Interferometer (IASI) satellite data for 2008–2017 using average morning winds, yielding a flushing time of 2.7 h, and 8.9 Gg yr−1. The ratio of EF(H2S) to EF(NH3) for the research dairy from AMOG data were applied to IASI NH3 emissions to derive H2S exposure concentration maps for the Chino area, which ranged to 10–30 ppb H2S for many populated areas. Combining remote sensing with in situ concentrations of multiple emitted gases can allow derivation of emissions at the sub-facility, facility, and larger scales, providing spatial and temporal coverage that can translate into exposure estimates for use in epidemiology studies and regulation development. Furthermore, with high fidelity information at the sub-facility level we can identify best practices and opportunities to sustainably and holistically reduce husbandry emissions. © 2019 Elsevier B.V.
BibTeX:
@article{Leifer2020,
  author = {Leifer, Ira and Melton, Christopher and Tratt, David M. and Buckland, Kerry N. and Chang, Clement S. and Clarisse, Lieven and Franklin, Meredith and Hall, Jeffrey L. and Brian Leen, J. and Lundquist, Tryg and VanDamme, Martin and Vigil, Sam and Whitburn, Simon},
  title = {Estimating exposure to hydrogen sulfide from animal husbandry operations using satellite ammonia as a proxy: Methodology demonstration},
  journal = {Science of the Total Environment},
  year = {2020},
  volume = {709},
  note = {All Open Access, Bronze Open Access},
  doi = {10.1016/j.scitotenv.2019.134508}
}
Lopez T, Clarisse L, Schwaiger H, Van Eaton A, Loewen M, Fee D, Lyons J, Wallace K, Searcy C, Wech A, Haney M, Schneider D and Graham N (2020), "Constraints on eruption processes and event masses for the 2016–2017 eruption of Bogoslof volcano, Alaska, through evaluation of IASI satellite SO2 masses and complementary datasets", Bulletin of Volcanology. Vol. 82(2)
Abstract: Bogoslof volcano, Alaska, experienced at least 70 explosive eruptions between 12 December 2016 and 31 August 2017. Due to its remote location and limited local monitoring network, this eruption was monitored and characterized primarily using remote geophysical and satellite techniques. SO2 emissions from Bogoslof were persistently detected by the Infrared Atmospheric Sounding Interferometer (IASI) satellite sensors. Of Bogoslof’s 70 explosive events, 50% produced measurable SO2 masses ranging from 0.1 to 21.5 kt, with a median and standard deviation of 0.7 ± 4.0 kt SO2, respectively. Here, we compare IASI-derived SO2 masses from Bogoslof events to complementary geophysical datasets to provide insights into eruption source processes, namely the degree of seawater scrubbing of water-soluble SO2 and variations in magma flux. Correlations with the number of lightning strokes and infrasound energy are expected to indicate magma-flux as a controlling process, while correlations with infrasound frequency index are expected to indicate variations in vent-water content as a controlling factor. These comparisons suggest that the measured SO2 masses are primarily a function of eruption magnitude (degassed magma mass) and that scrubbing of SO2 emissions by vent seawater may have exerted a minor effect on the observed SO2 masses. SO2 masses were combined with petrologic constraints on melt inclusion and matrix glass S concentrations to calculate degassed magma masses and volumes. The cumulative SO2-derived degassed magma mass and estimated volume (dense-rock equivalent) for the full Bogoslof eruption were found to be 2.8 × 1010 kg and 9.3 × 106 m3, respectively. When individual event masses are compared against event masses calculated using an empirical plume-height method, a strong correlation is found (R2 = 0.83), with better than order-of-magnitude agreement in most cases. These estimates of eruption masses provide useful information on the magnitude, behavior, and associated hazards of the 2016–2017 eruption, and potentially future unrest at Bogoslof volcano. © 2020, International Association of Volcanology & Chemistry of the Earth's Interior.
BibTeX:
@article{Lopez2020,
  author = {Lopez, Taryn and Clarisse, Lieven and Schwaiger, Hans and Van Eaton, Alexa and Loewen, Matthew and Fee, David and Lyons, John and Wallace, Kristi and Searcy, Cheryl and Wech, Aaron and Haney, Matthew and Schneider, David and Graham, Nathan},
  title = {Constraints on eruption processes and event masses for the 2016–2017 eruption of Bogoslof volcano, Alaska, through evaluation of IASI satellite SO2 masses and complementary datasets},
  journal = {Bulletin of Volcanology},
  year = {2020},
  volume = {82},
  number = {2},
  doi = {10.1007/s00445-019-1348-z}
}
Mukai M, Hirayama Y, Watanabe Y, Schiffmann S, Ekman J, Godefroid M, Schury P, Kakiguchi Y, Oyaizu M, Wada M, Jeong S, Moon J, Park J, Ishiyama H, Kimura S, Ueno H, Ahmed M, Ozawa A, Watanabe H, Kanaya S and Miyatake H (2020), "In-gas-cell laser resonance ionization spectroscopy of Ir 196,197,198", Physical Review C. Vol. 102(5)
Abstract: Hyperfine structure (HFS) measurements of neutron-rich iridium isotopes Ir196,197,198 (Z=77,N=119-121) were performed via in-gas-cell laser resonance ionization spectroscopy at the KEK Isotope Separation System. Magnetic dipole moments μ and isotope shifts were determined from the HFS spectra. The variation of mean-square charge radii and quadrupole deformation parameters of these isotopes were evaluated from the isotope shifts. The μ value of Ir197 agreed with a theoretical value based on the strong coupling model, and the Ir nucleus was interpreted as prolately deformed by the theoretical calculations. The μ values of Ir196,198 were also compared with semiempirical values calculated based on the strong coupling model. From the comparison, we can suggest the possible spin values of Iπ=1,2- for Ir196 and Iπ=1- for Ir198. © 2020 American Physical Society.
BibTeX:
@article{Mukai2020,
  author = {Mukai, M. and Hirayama, Y. and Watanabe, Y.X. and Schiffmann, S. and Ekman, J. and Godefroid, M. and Schury, P. and Kakiguchi, Y. and Oyaizu, M. and Wada, M. and Jeong, S.C. and Moon, J.Y. and Park, J.H. and Ishiyama, H. and Kimura, S. and Ueno, H. and Ahmed, M. and Ozawa, A. and Watanabe, H. and Kanaya, S. and Miyatake, H.},
  title = {In-gas-cell laser resonance ionization spectroscopy of Ir 196,197,198},
  journal = {Physical Review C},
  year = {2020},
  volume = {102},
  number = {5},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevC.102.054307}
}
Safieddine S, Bouillon M, Paracho A-C, Jumelet J, Tencé F, Pazmino A, Goutail F, Wespes C, Bekki S, Boynard A, Hadji-Lazaro J, Coheur P-F, Hurtmans D and Clerbaux C (2020), "Antarctic Ozone Enhancement During the 2019 Sudden Stratospheric Warming Event", Geophysical Research Letters. Vol. 47(14)
Abstract: We analyze the 2019 sudden stratospheric warming event that occurred in the Southern Hemisphere through its impact on the Antarctic ozone. Using temperature, ozone, and nitric acid data from the Infrared Atmospheric Sounding Interferometer (IASI), our results show that the average increase in stratospheric temperature reached a maximum of 34.4° on 20 September in the [60–90]°S latitude range when compared to the past 3 years. Dynamical parameters suggest a locally reversed and weakened zonal winds and a shift in the location of the polar jet vortex. This led to air masses mixing, to a reduced polar stratospheric clouds formation detected at a ground station, and as such to lower ozone and nitric acid depletion. 2019 total ozone columns for the months of September, October, and November were on average higher by 29%, 28%, and 26%, respectively, when compared to the 11-year average of the same months. ©2020. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Safieddine2020a,
  author = {Safieddine, Sarah and Bouillon, Marie and Paracho, Ana-Claudia and Jumelet, Julien and Tencé, Florent and Pazmino, Andrea and Goutail, Florence and Wespes, Catherine and Bekki, Slimane and Boynard, Anne and Hadji-Lazaro, Juliette and Coheur, Pierre-François and Hurtmans, Daniel and Clerbaux, Cathy},
  title = {Antarctic Ozone Enhancement During the 2019 Sudden Stratospheric Warming Event},
  journal = {Geophysical Research Letters},
  year = {2020},
  volume = {47},
  number = {14},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2020GL087810}
}
Safieddine S, Parracho AC, George M, Aires F, Pellet V, Clarisse L, Whitburn S, Lezeaux O, Thépaut J-N, Hersbach H, Radnoti G, Goettsche F, Martin M, Doutriaux-Boucher M, Coppens D, August T, Zhou DK and Clerbaux C (2020), "Artificial neural networks to retrieve land and sea skin temperature from IASI", Remote Sensing. Vol. 12(17)
Abstract: Surface skin temperature (Tskin) derived from infrared remote sensors mounted on board satellites provides a continuous observation of Earth's surface and allows the monitoring of global temperature change relevant to climate trends. In this study, we present a fast retrieval method for retrieving Tskin based on an artificial neural network (ANN) from a set of spectral channels selected from the Infrared Atmospheric Sounding Interferometer (IASI) using the information theory/entropy reduction technique. Our IASI Tskin product (i.e., TANN) is evaluated against Tskin from EUMETSAT Level 2 product, ECMWF Reanalysis (ERA5), SEVIRI observations, and ground in situ measurements. Good correlations between IASI TANN and the Tskin from other datasets are shown by their statistic data, such as a mean bias and standard deviation (i.e., [bias, STDE]) of [0.55, 1.86 °C], [0.19, 2.10 °C], [-1.5, 3.56 °C], from EUMETSAT IASI L-2 product, ERA5, and SEVIRI. When compared to ground station data, we found that all datasets did not achieve the needed accuracy at several months of the year, and better results were achieved at nighttime. Therefore, comparison with ground-based measurements should be done with care to achieve the ±2 °C accuracy needed, by choosing, for example, a validation site near the station location. On average, this accuracy is achieved, in particular at night, leading to the ability to construct a robust Tskin dataset suitable for Tskin long-term spatio-temporal variability and trend analysis. © 2020 by the authors.
BibTeX:
@article{Safieddine2020,
  author = {Safieddine, Sarah and Parracho, Ana Claudia and George, Maya and Aires, Filipe and Pellet, Victor and Clarisse, Lieven and Whitburn, Simon and Lezeaux, Olivier and Thépaut, Jean-Noël and Hersbach, Hans and Radnoti, Gabor and Goettsche, Frank and Martin, Maria and Doutriaux-Boucher, Marie and Coppens, Dorothée and August, Thomas and Zhou, Daniel K. and Clerbaux, Cathy},
  title = {Artificial neural networks to retrieve land and sea skin temperature from IASI},
  journal = {Remote Sensing},
  year = {2020},
  volume = {12},
  number = {17},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/RS12172777}
}
Schiffmann S, Filippin L, Baye D and Godefroid M (2020), "POLALMM: A program to compute polarizabilities for nominal one-electron systems using the Lagrange-mesh method", Computer Physics Communications. Vol. 256
Abstract: We present a program to compute polarizabilities of nominal one-electron systems using the Lagrange-mesh method (LMM) (Baye, 2015), that was used by Filippin et al., (2018). A semiempirical-core-potential approach is implemented, ultimately solving a Dirac-like equation by diagonalizing the corresponding Hamiltonian matrix. In order to build the core potential, the core orbitals are obtained from independent calculations using the GRASP2018 package (Fischer et al., 2019). Therefore we provide an easy-to-use interface between the GRASP2018 package and the LMM complete finite basis, allowing to switch easily from one one-electron basis to the other. Program summary: Program Title: POLALMM CPC Library link to program files: http://dx.doi.org/10.17632/6mw5gdwfkt.1 Licensing provisions: MIT license Programming language: Fortran90 Nature of problem: Determination of the dipole and quadrupole polarizabilities. Solution method: We combine a semiempirical-core-potential approach with the numerical Lagrange-mesh method to solve a Dirac-like one-electron equation [2]. The building of the core potential requires the prior knowledge of core orbitals provided by GRASP [3]. Two free parameters are optimized by fitting the computed single-electron valence energies to their experimental reference value. References: [1] The Lagrange-mesh method, D. Baye, Phys. Rep. 565 (2015) 1-107 [2] Relativistic semiempirical-core-potential calculations in Ca+, Ba+ and Sr+ ions on Lagrange meshes, L. Filippin, S. Schiffmann, J. Dohet-Eraly, D. Baye and M. Godefroid, Phys. Rev. A 97 (2018) 012506 [3] GRASP2018 - A Fortran 95 version of the General Relativistic Atomic Structure Package, C. FroeseFischer, G. Gaigalas, P. Jönsson and J. Bieroń, Comput. Phys. Commun. 237 (2019) 184-187 © 2020 Elsevier B.V.
BibTeX:
@article{Schiffmann2020,
  author = {Schiffmann, Sacha and Filippin, Livio and Baye, Daniel and Godefroid, Michel},
  title = {POLALMM: A program to compute polarizabilities for nominal one-electron systems using the Lagrange-mesh method},
  journal = {Computer Physics Communications},
  year = {2020},
  volume = {256},
  doi = {10.1016/j.cpc.2020.107452}
}
Schiffmann S, Godefroid M, Ekman J, Jönsson P and Fischer CF (2020), "Natural orbitals in multiconfiguration calculations of hyperfine-structure parameters", Physical Review A. Vol. 101(6)
Abstract: We are reinvestigating the hyperfine structure of sodium using a fully relativistic multiconfiguration approach. In the fully relativistic approach, the computational strategy somewhat differs from the original nonrelativistic counterpart used by P. Jönsson, Phys. Rev. A 53, 4021 (1996)PLRAAN1050-294710.1103/PhysRevA.53.4021. Numerical instabilities force us to use a layer-by-layer approach that has some broad unexpected effects. Core correlation is found to be significant and therefore should be described in an adequate orbital basis. The natural-orbital basis provides an interesting alternative to the orbital basis from the layer-by-layer approach, allowing us to overcome some deficits of the latter, giving rise to magnetic dipole hyperfine structure constant values, in excellent agreement with observations. Effort is made to assess the reliability of the natural-orbital bases and to illustrate their efficiency. © 2020 American Physical Society
BibTeX:
@article{Schiffmann2020a,
  author = {Schiffmann, Sacha and Godefroid, Michel and Ekman, Jörgen and Jönsson, Per and Fischer, Charlotte Froese},
  title = {Natural orbitals in multiconfiguration calculations of hyperfine-structure parameters},
  journal = {Physical Review A},
  year = {2020},
  volume = {101},
  number = {6},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.101.062510}
}
Song C, Wang K, Wang K, Del Zanna G, Jönsson P, Si R, Godefroid M, Gaigalas G, Radžiūtė L, Rynkun P, Zhao X, Yan J and Chen C (2020), "Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: N = 4 Levels in P-like Ions from Mn Xi to Ni XIV", Astrophysical Journal, Supplement Series. Vol. 247(2)
Abstract: Using the multiconfiguration Dirac-Hartree-Fock and the relativistic configuration interaction methods, a consistent set of transition energies and radiative transition data for the lowest 546 (623, 701, and 745) states of the 3p43, 3s3p23d2, 3s3p33, 3s3p4, 3s23d33, 3s23p23d, 3s23p24d, 3s23p24s, 3p33d2, 3p5, 3s3p3d3, 3s3p33d, 3s3p34s, 3s23p3d2, 3s23p24p, and 3s23p3 configurations in Mn xi (Fe xii, Co xiii, and Ni xiv) is provided. The comparison between calculated excitation energies for the n = 4 states and available experimental values for Fe xii indicate that the calculations are highly accurate, with uncertainties of only a few hundred cm-1. Lines from these states are prominent in the soft X-rays. With the present calculations, several recent new identifications are confirmed. Other identifications involving 3p24d levels in Fe xii that were found to be questionable are discussed and a few new assignments are recommended. As some n = 4 states of the other ions also show large discrepancies between experimental and calculated energies, we reassess their identification. The present study provides highly accurate atomic data for the n = 4 states of P-like ions of astrophysical interest, for which experimental data are scarce. © 2020. The American Astronomical Society. All rights reserved.
BibTeX:
@article{Song2020,
  author = {Song, C.X. and Wang, K. and Wang, K. and Del Zanna, G. and Jönsson, P. and Si, R. and Godefroid, M. and Gaigalas, G. and Radžiūtė, L. and Rynkun, P. and Zhao, X.H. and Yan, J. and Chen, C.Y.},
  title = {Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: N = 4 Levels in P-like Ions from Mn Xi to Ni XIV},
  journal = {Astrophysical Journal, Supplement Series},
  year = {2020},
  volume = {247},
  number = {2},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.3847/1538-4365/ab7cc6}
}
Theys N, Volkamer R, Müller J-F, Zarzana K, Kille N, Clarisse L, De Smedt I, Lerot C, Finkenzeller H, Hendrick F, Koenig T, Lee C, Knote C, Yu H and vanRoozendael M (2020), "Global nitrous acid emissions and levels of regional oxidants enhanced by wildfires", Nature Geoscience. Vol. 13(10), pp. 681 – 686.
Abstract: Nitrous acid (HONO) is a precursor of the hydroxyl radical in the atmosphere, which controls the degradation of greenhouse gases, contributes to photochemical smog and ozone production, and influences air quality. Although biomass burning is known to contribute substantially to global aerosols and reactive gas emissions, pyrogenic contributions to HONO emissions are poorly constrained and often omitted in models. Here we present a global survey of TROPOMI/Sentinel-5 Precursor satellite sounder observations and show that HONO emissions are consistently enhanced in fresh wildfire plumes. Comparing major ecosystems (savanna, grassland, shrubland and tropical and extratropical forests), we found that the enhancement ratios of HONO to nitrogen dioxide varied systematically with biome type, with the lowest in savannas and grasslands and highest in extratropical evergreen forests. Supported by airborne measurements, we demonstrate that previous assessments underestimate pyrogenic HONO emissions by a factor of 2–4 across all ecosystem types. We estimate that HONO emissions are responsible for two-thirds of the hydroxyl radical production in fresh wildfire plumes worldwide and act to accelerate oxidative plume chemistry and ozone production. Our findings suggest that pyrogenic HONO emissions have a substantial impact on atmospheric composition, which enhances regional ozone levels by up to 7 ppbv. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.
BibTeX:
@article{Theys2020,
  author = {Theys, N. and Volkamer, R. and Müller, J.-F. and Zarzana, K.J. and Kille, N. and Clarisse, L. and De Smedt, I. and Lerot, C. and Finkenzeller, H. and Hendrick, F. and Koenig, T.K. and Lee, C.F. and Knote, C. and Yu, H. and vanRoozendael, M.},
  title = {Global nitrous acid emissions and levels of regional oxidants enhanced by wildfires},
  journal = {Nature Geoscience},
  year = {2020},
  volume = {13},
  number = {10},
  pages = {681 – 686},
  note = {All Open Access, Green Open Access},
  doi = {10.1038/s41561-020-0637-7}
}
Tournigand P-Y, Cigala V, Lasota E, Hammouti M, Clarisse L, Brenot H, Prata F, Kirchengast G, Steiner AK and Biondi R (2020), "A multi-sensor satellite-based archive of the largest SO2volcanic eruptions since 2006", Earth System Science Data. Vol. 12(4), pp. 3139 – 3159.
Abstract: We present a multi-sensor archive collecting spatial and temporal information about volcanic SO2 clouds generated by the 11 largest eruptions of this century. The detection and monitoring of volcanic clouds are an important topic for aviation management, climate issues and weather forecasts. Several studies focusing on single eruptive events exist, but no archive available at the moment combines quantitative data from as many instruments. We archived and collocated the SO2 vertical column density estimations from three different satellite instruments (AIRS, IASI and GOME-2), atmospheric parameters as vertical profiles from the Global Navigation Satellite Systems (GNSS) Radio Occultations (RO), and the cloud-top height and aerosol type from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). Additionally, we provide information about the cloud-top height from three different algorithms and the atmospheric anomaly due to the presence of the cloud. The dataset is gathering 206 d of SO2 data, collocated with 44 180 backscatter profiles and 64 764 radio occultation profiles. The modular structure of the archive allows an easy collocation of the datasets according to the users' needs, and the cross-comparison of the datasets shows different consistency of the parameters estimated with different sensors and algorithms, according to the sensitivity and resolution of the instruments. The data described here are published with a DOI at https://doi.org/10.5880/fidgeo.2020.016 (Tournigand et al., 2020a). © 2020 Author(s).
BibTeX:
@article{Tournigand2020a,
  author = {Tournigand, Pierre-Yves and Cigala, Valeria and Lasota, Elzbieta and Hammouti, Mohammed and Clarisse, Lieven and Brenot, Hugues and Prata, Fred and Kirchengast, Gottfried and Steiner, Andrea K. and Biondi, Riccardo},
  title = {A multi-sensor satellite-based archive of the largest SO2volcanic eruptions since 2006},
  journal = {Earth System Science Data},
  year = {2020},
  volume = {12},
  number = {4},
  pages = {3139 – 3159},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/essd-12-3139-2020}
}
Tournigand P-Y, Cigala V, Prata AJ, Steiner AK, Kirchengast G, Brenot H, Clarisse L and Biondi R (2020), "The 2015 Calbuco Volcanic Cloud Detection Using GNSS Radio Occultation and Satellite Lidar", International Geoscience and Remote Sensing Symposium (IGARSS). , pp. 6834 – 6837.
Abstract: Explosive volcanic eruptions can generate ash and gas clouds rising to the stratosphere and dispersing on a global scale. Such volcanic features are at the origin of many hazards including aircraft engine damages, ash fallouts and health threats. It is thus crucial, to mitigate such hazards, to monitor volcanic clouds dispersion and altitude. In this study, we use the Global Navigation Satellite System (GNSS) Radio Occultation (RO) technique to assess the volcanic cloud altitude resulting from the 2015 Calbuco's eruption. We find volcanic cloud altitude estimations based on RO data in good agreement with the collocated Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) and the Infrared Atmospheric Sounding Interferometer (IASI). The preliminary results of this study confirm that automatized RO profiles processing has great potential in the field of volcanic clouds monitoring. © 2020 IEEE.
BibTeX:
@conference{Tournigand2020,
  author = {Tournigand, Pierre-Yves and Cigala, Valeria and Prata, Alfredo J. and Steiner, Andrea K. and Kirchengast, Gottfried and Brenot, Hugues and Clarisse, Lieven and Biondi, Riccardo},
  title = {The 2015 Calbuco Volcanic Cloud Detection Using GNSS Radio Occultation and Satellite Lidar},
  journal = {International Geoscience and Remote Sensing Symposium (IGARSS)},
  year = {2020},
  pages = {6834 – 6837},
  doi = {10.1109/IGARSS39084.2020.9323356}
}
Turquety S, Menut L, Siour G, Mailler S, Hadji-Lazaro J, George M, Clerbaux C, Hurtmans D and Coheur P-F (2020), "APIFLAME v2.0 biomass burning emissions model: Impact of refined input parameters on atmospheric concentration in Portugal in summer 2016", Geoscientific Model Development. Vol. 13(7), pp. 2981 – 3009.
Abstract: Biomass burning emissions are a major source of trace gases and aerosols. Wildfires being highly variable in time and space, calculating emissions requires a numerical tool able to estimate fluxes at the kilometer scale and with an hourly time step. Here, the APIFLAME model version 2.0 is presented. It is structured to be modular in terms of input databases and processing methods. The main evolution compared to version 1.0 is the possibility of merging burned area and fire radiative power (FRP) satellite observations to modulate the temporal variations of fire emissions and to integrate small fires that may not be detected in the burned area product. Accounting for possible missed detection due to small fire results in an increase in burned area ranging from ∼5% in Africa and Australia to ∼30% in North America on average over the 2013-2017 time period based on the Moderate-Resolution Imaging Spectroradiometer (MODIS) Collection 6 fire products. An illustration for the case of southwestern Europe during the summer of 2016, marked by large wildfires in Portugal, is presented. Emissions calculated using different possible configurations of APIFLAME show a dispersion of 80% on average over the domain during the largest wildfires (8-14 August 2016), which can be considered as an estimate of uncertainty of emissions. The main sources of uncertainty studied, by order of importance, are the emission factors, the calculation of the burned area, and the vegetation attribution. The aerosol (PM10) and carbon monoxide (CO) concentrations simulated with the CHIMERE regional chemistry transport model (CTM) are consistent with observations (good timing for the beginning and end of the events, ±1d for the timing of the peak values) but tend to be overestimated compared to observations at surface stations. On the contrary, vertically integrated concentrations tend to be underestimated compared to satellite observations of total column CO by the Infrared Atmospheric Sounding Interferometer (IASI) instrument and aerosol optical depth (AOD) by MODIS. This underestimate is lower close to the fire region (5%-40% for AOD depending on the configuration and 8%-18% for total CO) but rapidly increases downwind. For all comparisons, better agreement is achieved when emissions are injected higher into the free troposphere using a vertical profile as estimated from observations of aerosol plume height by the Multi-angle Imaging SpectroRadiometer (MISR) satellite instrument (injection up to 4km). Comparisons of aerosol layer heights to observations by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) show that some parts of the plume may still be transported at too low an altitude. The comparisons of the different CTM simulations to observations point to uncertainties not only on emissions (total mass and daily variability) but also on the simulation of their transport with the CTM and mixing with other sources. Considering the uncertainty of the emission injection profile and of the modeling of the transport of these dense plumes, it is difficult to fully validate emissions through comparisons between model simulations and atmospheric observations. © Author(s) 2020.
BibTeX:
@article{Turquety2020,
  author = {Turquety, Solène and Menut, Laurent and Siour, Guillaume and Mailler, Sylvain and Hadji-Lazaro, Juliette and George, Maya and Clerbaux, Cathy and Hurtmans, Daniel and Coheur, Pierre-François},
  title = {APIFLAME v2.0 biomass burning emissions model: Impact of refined input parameters on atmospheric concentration in Portugal in summer 2016},
  journal = {Geoscientific Model Development},
  year = {2020},
  volume = {13},
  number = {7},
  pages = {2981 – 3009},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/gmd-13-2981-2020}
}
Urbain X, DeRuette N, Dochain A, Launoy T, Nascimento R, Kaminska M, Stockett M, Loreau J, Liévin J, Vaeck N, Thomas R, Schmidt H and Cederquist H (2020), "Merged beam studies of mutual neutralization at subthermal collision energies", Journal of Physics: Conference Series. Vol. 1412(6)
Abstract: We have measured the kinetic energy distributions for the mutual neutralization of a large ensemble of atomic anions and cations. Ions are accelerated to equal velocities in a merged beam setup, enabling measurements at collision energies as low as 5 meV. Three-dimensional momentum imaging is performed with two position sensitive detectors located several meters downstream from the few centimeter long region where the beams overlap. An unprecedented resolution in the kinetic energy release (KER) spectra allows us to identify the states of both reactants and products down to their fine structure. Knowing the angular distribution of the products in the laboratory and center-of-mass frame, allows for total, partial, and differential cross sections to be retrieved. © Published under licence by IOP Publishing Ltd.
BibTeX:
@conference{Urbain2020,
  author = {Urbain, X. and DeRuette, N. and Dochain, A. and Launoy, T. and Nascimento, R.F. and Kaminska, M. and Stockett, M.H. and Loreau, J. and Liévin, J. and Vaeck, N. and Thomas, R.D. and Schmidt, H.T. and Cederquist, H.},
  title = {Merged beam studies of mutual neutralization at subthermal collision energies},
  journal = {Journal of Physics: Conference Series},
  year = {2020},
  volume = {1412},
  number = {6},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1088/1742-6596/1412/6/062009}
}
VanGent J, Brenot H, Theys N, Clarisse L, Wilson S, Clarkson R and vanRoozendael M (2020), "Prototyping of a Multi-Hazard Early Warning System for Aviation and Development of NRT Alert Products within the EUNADICS-AV and OPAS Projects", International Geoscience and Remote Sensing Symposium (IGARSS). , pp. 6859 – 6862.
Abstract: The eruption of the Eyjafjöll volcano in 2010 has shown that aviation can be very vulnerable to natural disasters. Although such events are rare, the consequences for aviation can be enormous, on both the economic and human scale. Nowadays many techniques are available to measure hazards to aviation, yet there is still no Europe wide warning system for this kind of disasters. The EUNADICS-AV project aimed at filling this gap, by providing fast information to the aviation community. In addition, the ongoing Engage-KTN OPAS projects involves the development of an algorithm for the retrieval of the height of sulfur dioxide (SO2) plumes, a proxy for the presence of volcanic ash. This paper reports on the major contributions to these two projects: the development of an early warning system, the SO2 layer height developments, and the creation of standardized alert products. © 2020 IEEE.
BibTeX:
@conference{VanGent2020,
  author = {VanGent, Jeroen and Brenot, Hugues and Theys, Nicolas and Clarisse, Lieven and Wilson, Scott and Clarkson, Rory and vanRoozendael, Michel},
  title = {Prototyping of a Multi-Hazard Early Warning System for Aviation and Development of NRT Alert Products within the EUNADICS-AV and OPAS Projects},
  journal = {International Geoscience and Remote Sensing Symposium (IGARSS)},
  year = {2020},
  pages = {6859 – 6862},
  doi = {10.1109/IGARSS39084.2020.9324335}
}
Viatte C, Clerbaux C, Maes C, Daniel P, Garello R, Safieddine S and Ardhuin F (2020), "Air Pollution and Sea Pollution Seen from Space", Surveys in Geophysics. Vol. 41(6), pp. 1583 – 1609.
Abstract: Air pollution and sea pollution are both impacting human health and all the natural environments on Earth. These complex interactions in the biosphere are becoming better known and understood. Major progress has been made in recent past years for understanding their societal and environmental impacts, thanks to remote sensors placed aboard satellites. This paper describes the state of the art of what is known about air pollution and focuses on specific aspects of marine pollution, which all benefit from the improved knowledge of the small-scale eddy field in the oceans. Examples of recent findings are shown, based on the global observing system (both remote and in situ) with standardized protocols for monitoring emerging environmental threats at the global scale. © 2020, The Author(s).
BibTeX:
@article{Viatte2020,
  author = {Viatte, Camille and Clerbaux, Cathy and Maes, Christophe and Daniel, Pierre and Garello, René and Safieddine, Sarah and Ardhuin, Fabrice},
  title = {Air Pollution and Sea Pollution Seen from Space},
  journal = {Surveys in Geophysics},
  year = {2020},
  volume = {41},
  number = {6},
  pages = {1583 – 1609},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1007/s10712-020-09599-0}
}
Viatte C, Wang T, VanDamme M, Dammers E, Meleux F, Clarisse L, Shephard MW, Whitburn S, François Coheur P, Cady-Pereira KE and Clerbaux C (2020), "Atmospheric ammonia variability and link with particulate matter formation: A case study over the Paris area", Atmospheric Chemistry and Physics. Vol. 20(1), pp. 577 – 596.
Abstract: The Paris megacity experiences frequent particulate matter (i.e.PM2:5, particulate matter with a diameter less than 2.5 μm) pollution episodes in spring (March.April). At this time of the year, large numbers of the particles consist of ammonium sulfate and nitrate which are formed from ammonia (NH3) released during fertilizer spreading practices and transported from the surrounding areas to Paris. There is still limited knowledge of the emission sources around Paris, their magnitude, and their seasonality. Using space-borne NH3 observation records of 10 years (2008.2017) and 5 years (2013.2017) provided by the Infrared Atmospheric Sounding Interferometer (IASI) and the Cross-Track Infrared Sounder (CrIS) instrument, regional patterns of NH3 variabilities (seasonal and interannual) are derived. Observations reveal identical high seasonal variability with three major NH3 hotspots found from March to August. The high interannual variability is discussed with respect to atmospheric total precipitation and temperature. A detailed analysis of the seasonal cycle is performed using both IASI and CrIS instrument data, together with outputs from the CHIMERE atmospheric model. For 2014 and 2015, the CHIMERE model shows coefficients of determination of 0.58 and 0.18 when compared to IASI and CrIS, respectively. With respect to spatial variability, the CHIMERE monthly NH3 concentrations in spring show a slight underrepresentation over Belgium and the United Kingdom and an overrepresentation in agricultural areas in the French Brittany.Pays de la Loire and Plateau du Jura region, as well as in northern Switzerland. In addition, PM2.5 concentrations derived from the CHIMERE model have been evaluated against surface measurements from the Airparif network over Paris, with which agreement was found (r2 = 0.56) with however an underestimation during spring pollution events. Using HYSPLIT cluster analysis of back trajectories, we show that NH3 total columns measured in spring over Paris are enhanced when air masses originate from the north-east (e.g. the Netherlands and Belgium), highlighting the importance of long-range transport in the NH3 budget over Paris. Variability in NH3 in the north-east region is likely to impact NH3 concentrations in the Parisian region since the crosscorrelation function is above 0.3 (at lag=0 and 1 d). Finally, we quantify the key meteorological parameters driving the specific conditions important for the formation of PM2.5 from NH3 in the Ile-de-France region in spring. Datadriven results based on surface PM2.5 measurements from the Airparif network and IASI NH3 measurements show that a combination of the factors such as a low boundary layer of ∼ 500 m, a relatively low temperature of 5 °C, a high relative humidity of 70 %, and wind from the north-east contributes to a positive PM2.5 and NH3 correlation. © 2020 Author(s).
BibTeX:
@article{Viatte2020a,
  author = {Viatte, Camille and Wang, Tianze and VanDamme, Martin and Dammers, Enrico and Meleux, Frederik and Clarisse, Lieven and Shephard, Mark W. and Whitburn, Simon and François Coheur, Pierre and Cady-Pereira, Karen E. and Clerbaux, Cathy},
  title = {Atmospheric ammonia variability and link with particulate matter formation: A case study over the Paris area},
  journal = {Atmospheric Chemistry and Physics},
  year = {2020},
  volume = {20},
  number = {1},
  pages = {577 – 596},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-20-577-2020}
}
Wang K, Wang K, Wang K, Jönsson P, Del Zanna G, Godefroid M, Chen Z, Chen C and Yan J (2020), "Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: Cl-like Ions from Cr viii to Zn xiv", Astrophysical Journal, Supplement Series. Vol. 246(1)
Abstract: We use the multiconfiguration Dirac-Hartree-Fock (MCDHF) method combined with the relativistic configuration interaction approach (GRASP2K) to provide a consistent set of transition energies and radiative transition data for the lower n = 3 states in all Cl-like ions of astrophysical importance, from Cr viii to Zn xiv. We also provide excitation energies calculated for Fe x using the many-body perturbation theory (MBPT, implemented within FAC). The comparison of the present MCDHF results with MBPT and with the available experimental energies indicates that the theoretical excitation energies are highly accurate, with uncertainties of only a few hundred cm-1. Detailed comparisons for Fe x and Ni xii highlight discrepancies in the experimental energies found in the literature. Several new identifications are proposed. © 2019. The American Astronomical Society. All rights reserved.
BibTeX:
@article{Wang2020,
  author = {Wang, K. and Wang, K. and Wang, K. and Jönsson, P. and Del Zanna, G. and Godefroid, M. and Chen, Z.B. and Chen, C.Y. and Yan, J.},
  title = {Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: Cl-like Ions from Cr viii to Zn xiv},
  journal = {Astrophysical Journal, Supplement Series},
  year = {2020},
  volume = {246},
  number = {1},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.3847/1538-4365/ab5530}
}
Whitburn S, Clarisse L, Bauduin S, George M, Hurtmans D, Safieddine S, Coheur PF and Clerbaux C (2020), "Spectrally resolved fluxes from IASI data: Retrieval algorithm for clear-sky measurements", Journal of Climate. Vol. 33(16), pp. 6971 – 6988.
Abstract: Space-based measurements of the outgoing longwave radiation (OLR) are essential for the study of Earth's climate system. While the CERES instrument provides accurate measurements of this quantity, its measurements are not spectrally resolved. Here we present a high-resolution OLR product (sampled at 0.25 cm21), derived from measurements of the IASI satellite sounder. The applied methodology relies on precalculated angular distribution models (ADMs). These are usually calculated for tens to hundreds of different scene types (characterized by surface and atmosphere parameters). To guarantee accurate results in the range 645-2300 cm21 covered by IASI, we constructed ADMs for over 140 000 scenes. These were selected from one year of CAMS reanalysis data. A dissimilarity-based selection algorithm was applied to choose scenes as different from each other as possible, thereby maximizing the performance on real data, while keeping the number of scenes manageable. A comparison of the IASI OLR integrated over the 645-2300 cm21 range was performed with the longwave broadband OLR products from CERES and the AIRS instrument. The latter are systematically higher due to the contribution of the far infrared to the total IR spectral range, but as expected exhibit generally high spatial correlations with the IASI OLR, except for some areas in the tropical region. We also compared the IASI OLR against the spectrally resolved OLR derived from AIRS. A good agreement was found above 1200 cm21 while AIRS OLR appeared to be systematically higher in the atmospheric window region, likely related to differences in overpass time or to the use of a different cloud detection algorithm. © 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
BibTeX:
@article{Whitburn2020,
  author = {Whitburn, Simon and Clarisse, Lieven and Bauduin, Sophie and George, Maya and Hurtmans, Daniel and Safieddine, Sarah and Coheur, Pierre François and Clerbaux, Cathy},
  title = {Spectrally resolved fluxes from IASI data: Retrieval algorithm for clear-sky measurements},
  journal = {Journal of Climate},
  year = {2020},
  volume = {33},
  number = {16},
  pages = {6971 – 6988},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1175/JCLI-D-19-0523.1}
}
Yordanov DT, Rodríguez LV, Balabanski DL, Bieroń J, Bissell ML, Blaum K, Cheal B, Ekman J, Gaigalas G, Garcia Ruiz RF, Georgiev G, Gins W, Godefroid MR, Gorges C, Harman Z, Heylen H, Jönsson P, Kanellakopoulos A, Kaufmann S, Keitel CH, Lagaki V, Lechner S, Maaß B, Malbrunot-Ettenauer S, Nazarewicz W, Neugart R, Neyens G, Nörtershäuser W, Oreshkina NS, Papoulia A, Pyykkö P, Reinhard P-G, Sailer S, Sánchez R, Schiffmann S, Schmidt S, Wehner L, Wraith C, Xie L, Xu Z and Yang X (2020), "Structural trends in atomic nuclei from laser spectroscopy of tin", Communications Physics. Vol. 3(1)
Abstract: Tin is the chemical element with the largest number of stable isotopes. Its complete proton shell, comparable with the closed electron shells in the chemically inert noble gases, is not a mere precursor to extended stability; since the protons carry the nuclear charge, their spatial arrangement also drives the nuclear electromagnetism. We report high-precision measurements of the electromagnetic moments and isomeric differences in charge radii between the lowest 1/2+, 3/2+, and 11/2− states in 117–131Sn, obtained by collinear laser spectroscopy. Supported by state-of-the-art atomic-structure calculations, the data accurately show a considerable attenuation of the quadrupole moments in the closed-shell tin isotopes relative to those of cadmium, with two protons less. Linear and quadratic mass-dependent trends are observed. While microscopic density functional theory explains the global behaviour of the measured quantities, interpretation of the local patterns demands higher-fidelity modelling. © 2020, The Author(s).
BibTeX:
@article{Yordanov2020,
  author = {Yordanov, Deyan T. and Rodríguez, Liss V. and Balabanski, Dimiter L. and Bieroń, Jacek and Bissell, Mark L. and Blaum, Klaus and Cheal, Bradley and Ekman, Jörgen and Gaigalas, Gediminas and Garcia Ruiz, Ronald F. and Georgiev, Georgi and Gins, Wouter and Godefroid, Michel R. and Gorges, Christian and Harman, Zoltán and Heylen, Hanne and Jönsson, Per and Kanellakopoulos, Anastasios and Kaufmann, Simon and Keitel, Christoph H. and Lagaki, Varvara and Lechner, Simon and Maaß, Bernhard and Malbrunot-Ettenauer, Stephan and Nazarewicz, Witold and Neugart, Rainer and Neyens, Gerda and Nörtershäuser, Wilfried and Oreshkina, Natalia S. and Papoulia, Asimina and Pyykkö, Pekka and Reinhard, Paul-Gerhard and Sailer, Stefan and Sánchez, Rodolfo and Schiffmann, Sacha and Schmidt, Stefan and Wehner, Laura and Wraith, Calvin and Xie, Liang and Xu, Zhengyu and Yang, Xiaofei},
  title = {Structural trends in atomic nuclei from laser spectroscopy of tin},
  journal = {Communications Physics},
  year = {2020},
  volume = {3},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1038/s42005-020-0348-9}
}
Zhang CY, Wang K, Godefroid M, Jönsson P, Si R and Chen CY (2020), "Benchmarking calculations with spectroscopic accuracy of excitation energies and wavelengths in sulfur-like tungsten", Physical Review A. Vol. 101(3)
Abstract: Atomic properties of S-like W are evaluated through a state-of-the-art method, namely, the multiconfiguration Dirac-Hartree-Fock method combined with the relativistic configuration-interaction approach. The level energies, wavelengths, and transition parameters involving the 88 lowest levels of W58+ (W lix) are calculated. We discuss in detail the relative importance of the valence-and core-valence electron correlation effects, the Breit interaction, the higher-order retardation correction beyond the Breit interaction through the transverse photon interaction, and the quantum electrodynamical corrections. The present level energies are highly accurate, with uncertainties close to what can be achieved from spectroscopy. As such, they provide benchmark tests for other theoretical calculations of S-like W and should assist the spectroscopists in their assignment and identification of observed lines in complex spectra. © 2020 American Physical Society.
BibTeX:
@article{Zhang2020,
  author = {Zhang, Chun Yu and Wang, Kai and Godefroid, Michel and Jönsson, Per and Si, Ran and Chen, Chong Yang},
  title = {Benchmarking calculations with spectroscopic accuracy of excitation energies and wavelengths in sulfur-like tungsten},
  journal = {Physical Review A},
  year = {2020},
  volume = {101},
  number = {3},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.101.032509}
}
Zhang X, Jones D, Keller M, Jiang Z, Bourassa AE, Degenstein D and Clerbaux C (2020), "Global CO Emission Estimates Inferred from Assimilation of MOPITT CO, Together with Observations of O3, NO2, HNO3, and HCHO", Springer Proceedings in Complexity. , pp. 219 – 224.
Abstract: Atmospheric carbon monoxide (CO) emissions estimated from inverse modeling analyses exhibit large uncertainties, due, in part, to discrepancies in the tropospheric chemistry in atmospheric models. We attempt to reduce the uncertainties in CO emission estimates by constraining the modeled abundance of ozone (O3), nitrogen dioxide (NO2), nitric acid (HNO3), and formaldehyde (HCHO), which are constituents that play a key role in tropospheric chemistry. Using the GEOS-Chem four-dimensional variational (4D-Var) data assimilation system, we estimate CO emissions by assimilating observations of CO from the Measurement of Pollution In the Troposphere (MOPITT) and the Infrared Atmospheric Sounding Interferometer (IASI), together with observations of O3 from the Optical Spectrograph and InfraRed Imager System (OSIRIS) and IASI, NO2 and HCHO from the Ozone Monitoring Instrument (OMI), and HNO3 from the Microwave Limb Sounder (MLS). Although our focus is on quantifying CO emission estimates, we also infer surface emissions of nitrogen oxides (NOx = NO + NO2) and isoprene. Our results reveal that this multiple species chemical data assimilation produces a chemical consistent state that effectively adjusts the CO–O3–OH coupling in the model. The O3-induced changes in OH are particularly large in the tropics. We show that the analysis results in a tropospheric chemical state that is better constrained. Our experiments also evaluate the inferred CO emission estimates from major anthropogenic, biomass burning and biogenic sources. © Springer Nature Switzerland AG 2020.
BibTeX:
@conference{Zhang2020a,
  author = {Zhang, Xuesong and Jones, Dylan and Keller, Martin and Jiang, Zhe and Bourassa, Adam E. and Degenstein, D.A. and Clerbaux, Cathy},
  title = {Global CO Emission Estimates Inferred from Assimilation of MOPITT CO, Together with Observations of O3, NO2, HNO3, and HCHO},
  journal = {Springer Proceedings in Complexity},
  year = {2020},
  pages = {219 – 224},
  doi = {10.1007/978-3-030-22055-6_34}
}
Aoki S, Vandaele AC, Daerden F, Villanueva G, Liuzzi G, Thomas I, Erwin J, Trompet L, Robert S, Neary L, Viscardy S, Clancy R, Smith M, Lopez-Valverde M, Hill B, Ristic B, Patel M, Bellucci G, López-Moreno J-J, Alonso-Rodrigo G, Altieri F, Bauduin S, Bolsée D, Carrozzo G, Cloutis E, Crismani M, Da Pieve F, D’aversa E, Depiesse C, Etiope G, Fedorova AA, Funke B, Fussen D, Garcia-Comas M, Geminale A, Gérard J-C, Giuranna M, Gkouvelis L, Gonzalez-Galindo F, Holmes J, Hubert B, Ignatiev NI, Kaminski J, Karatekin O, Kasaba Y, Kass D, Kleinböhl A, Lanciano O, Lefèvre F, Lewis S, López-Puertas M, Mahieux A, Mason J, Mege D, Mumma MJ, Nakagawa H, Neefs E, Novak RE, Oliva F, Piccialli A, Renotte E, Ritter B, Schmidt F, Schneider N, Sindoni G, Teanby NA, Thiemann E, Trokhimovskiy A, Auwera JV, Whiteway J, Wilquet V, Willame Y, Wolff MJ, Wolkenberg P, Yelle R, Del Moral Beatriz A, Barzin P, Beeckman B, Benmoussa A, Berkenbosch S, Biondi D, Bonnewijn S, Candini GP, Clairquin R, Cubas J, Giordanengo B, Gissot S, Gomez A, Hathi B, Jeronimo Zafra J, Leese M, Maes J, Mazy E, Mazzoli A, Meseguer J, Morales R, Orban A, Pastor-Morales M, Perez-Grande I, Queirolo C, Rodriguez Gomez J, Saggin B, Samain V, Sanz Andres A, Sanz R, Simar J-F and Thibert T (2019), "Water Vapor Vertical Profiles on Mars in Dust Storms Observed by TGO/NOMAD", Journal of Geophysical Research: Planets. Vol. 124(12), pp. 3482 – 3497.
Abstract: It has been suggested that dust storms efficiently transport water vapor from the near-surface to the middle atmosphere on Mars. Knowledge of the water vapor vertical profile during dust storms is important to understand water escape. During Martian Year 34, two dust storms occurred on Mars: a global dust storm (June to mid-September 2018) and a regional storm (January 2019). Here we present water vapor vertical profiles in the periods of the two dust storms (Ls = 162–260° and Ls = 298–345°) from the solar occultation measurements by Nadir and Occultation for Mars Discovery (NOMAD) onboard ExoMars Trace Gas Orbiter (TGO). We show a significant increase of water vapor abundance in the middle atmosphere (40–100 km) during the global dust storm. The water enhancement rapidly occurs following the onset of the storm (Ls 190°) and has a peak at the most active period (Ls 200°). Water vapor reaches very high altitudes (up to 100 km) with a volume mixing ratio of  50 ppm. The water vapor abundance in the middle atmosphere shows high values consistently at 60°S-60°N at the growth phase of the dust storm (Ls = 195°–220°), and peaks at latitudes greater than 60°S at the decay phase (Ls = 220°–260°). This is explained by the seasonal change of meridional circulation: from equinoctial Hadley circulation (two cells) to the solstitial one (a single pole-to-pole cell). We also find a conspicuous increase of water vapor density in the middle atmosphere at the period of the regional dust storm (Ls = 322–327°), in particular at latitudes greater than 60°S. ©2019. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Aoki2019,
  author = {Aoki, S. and Vandaele, Ann Carine and Daerden, F. and Villanueva, G.L. and Liuzzi, G. and Thomas, I.R. and Erwin, J.T. and Trompet, L. and Robert, S. and Neary, L. and Viscardy, S. and Clancy, R.T. and Smith, M.D. and Lopez-Valverde, M.A. and Hill, B. and Ristic, B. and Patel, M.R. and Bellucci, G. and López-Moreno, J.-J. and Alonso-Rodrigo, Gustavo and Altieri, Francesca and Bauduin, Sophie and Bolsée, David and Carrozzo, Giacomo and Cloutis, Edward and Crismani, Matteo and Da Pieve, Fabiana and D’aversa, Emiliano and Depiesse, Cédric and Etiope, Giuseppe and Fedorova, Anna A. and Funke, Bernd and Fussen, Didier and Garcia-Comas, Maia and Geminale, Anna and Gérard, Jean-Claude and Giuranna, Marco and Gkouvelis, Leo and Gonzalez-Galindo, Francisco and Holmes, James and Hubert, Benoît and Ignatiev, Nicolay I. and Kaminski, Jacek and Karatekin, Ozgur and Kasaba, Yasumasa and Kass, David and Kleinböhl, Armin and Lanciano, Orietta and Lefèvre, Franck and Lewis, Stephen and López-Puertas, Manuel and Mahieux, Arnaud and Mason, Jon and Mege, Daniel and Mumma, Michael J. and Nakagawa, Hiromu and Neefs, Eddy and Novak, Robert E. and Oliva, Fabrizio and Piccialli, Arianna and Renotte, Etienne and Ritter, Birgit and Schmidt, Frédéric and Schneider, Nick and Sindoni, Giuseppe and Teanby, Nicholas A. and Thiemann, Ed and Trokhimovskiy, Alexander and Auwera, Jean Vander and Whiteway, James and Wilquet, Valerie and Willame, Yannick and Wolff, Michael J. and Wolkenberg, Paulina and Yelle, Roger and Del Moral Beatriz, Aparicio and Barzin, Pascal and Beeckman, Bram and Benmoussa, Ali and Berkenbosch, Sophie and Biondi, David and Bonnewijn, Sabrina and Candini, Gian Paolo and Clairquin, Roland and Cubas, Javier and Giordanengo, Boris and Gissot, Samuel and Gomez, Alejandro and Hathi, Brijen and Jeronimo Zafra, Jose and Leese, Mark and Maes, Jeroen and Mazy, Emmanuel and Mazzoli, Alexandra and Meseguer, Jose and Morales, Rafael and Orban, Anne and Pastor-Morales, M. and Perez-Grande, Isabel and Queirolo, Claudio and Rodriguez Gomez, Julio and Saggin, Bortolino and Samain, Valérie and Sanz Andres, Angel and Sanz, Rosario and Simar, Juan-Felipe and Thibert, Tanguy},
  title = {Water Vapor Vertical Profiles on Mars in Dust Storms Observed by TGO/NOMAD},
  journal = {Journal of Geophysical Research: Planets},
  year = {2019},
  volume = {124},
  number = {12},
  pages = {3482 – 3497},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2019JE006109}
}
Attafi Y, Galalou S, Kwabia Tchana F, VanderAuwera J, Ben Hassen A, Aroui H, Perrin A, Manceron L and Doizi D (2019), "Oxygen broadening and shift coefficients in the ν6 band of methyl iodide (12CH3I) at room temperature", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 239
Abstract: In this study we report the high-resolution measurements of oxygen pressure- broadening and pressure-induced shift coefficients for rovibrational transitions in the ν6 band of methyl iodide (12CH3I), centered at 892.918 cm–1. The results were obtained by analyzing fourteen high-resolution room temperature laboratory absorption spectra with a mono-spectrum non-linear least squares fitting of Voigt profiles. The data were recorded with the Bruker IF125HR Fourier transform spectrometer located at the LISA facility in Créteil, using a White type cell with a path length of 564.9 cm and total pressures up to 295 hPa. The measured oxygen-broadening coefficients range from 0.0648 to 0.1207 cm–1atm–1 at 295 K. The measured shift coefficients were all negative and varied between −0.00044 and −0.04984 cm–1atm–1. The average accuracy on the measured O2-broadening coefficients and pressure shift coefficients was estimated to about 4% and 11%, respectively. The O2-broadening coefficients obtained in the present work are compared with values reported in the literature for the ν5 band of CH3I, showing a satisfactory agreement with an average difference of about 8%. The shift coefficients are compared with values reported in the literature for the ν6 band of CH3F-Ar system, exhibiting the same order of magnitude and trend. The J and K rotational dependences of the O2-broadening coefficients have been observed and the latter modeled using empirical polynomial expansions. On average, the empirical expression reproduces the measured O2-broadening coefficients to within 3%. Using the measured broadening coefficients of the CH3I-O2 and CH3I-N2 [Attafi et al., J Quant Spectrosc Radiat Transf 231 (2019) 1–8] systems, we produced CH3I-air broadening coefficients, ranging from 0.0783 to 0.1385 cm–1atm–1 at 295 K. The present results and the data already available should be valuable not only for predicting the CH3I infrared spectrum in the atmosphere, but also for verifying theoretical calculations of pressure-broadening and pressure-shift coefficients in the ν6 region of methyl iodide spectra. © 2019
BibTeX:
@article{Attafi2019,
  author = {Attafi, Y. and Galalou, S. and Kwabia Tchana, F. and VanderAuwera, J. and Ben Hassen, A. and Aroui, H. and Perrin, A. and Manceron, L. and Doizi, D.},
  title = {Oxygen broadening and shift coefficients in the ν6 band of methyl iodide (12CH3I) at room temperature},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2019},
  volume = {239},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2019.106679}
}
Boichu M, Favez O, Riffault V, Petit J-E, Zhang Y, Brogniez C, Sciare J, Chiapello I, Clarisse L, Zhang S, Pujol-Söhne N, Tison E, Delbarre H and Goloub P (2019), "Large-scale particulate air pollution and chemical fingerprint of volcanic sulfate aerosols from the 2014-2015 Holuhraun flood lava eruption of Bárdarbunga volcano (Iceland)", Atmospheric Chemistry and Physics. Vol. 19(22), pp. 14253 – 14287.
Abstract: Volcanic sulfate aerosols play a key role in air quality and climate. However, the rate of oxidation of sulfur dioxide (SO2) precursor gas to sulfate aerosols (SO2-4 ) in volcanic plumes is poorly known, especially in the troposphere. Here we determine the chemical speciation as well as the intensity and temporal persistence of the impact on air quality of sulfate aerosols from the 2014-2015 Holuhraun flood lava eruption of Icelandic volcano Bárdarbunga. To do so, we jointly analyse a set of SO2 observations from satellite (OMPS and IASI) and ground-level measurements from air quality monitoring stations together with high temporal resolution mass spectrometry measurements of an Aerosol Chemical Speciation Monitor (ACSM) performed far from the volcanic source. We explore month/year long ACSM data in France from stations in contrasting environments, close and far from industrial sulfur-rich activities. We demonstrate that volcanic sulfate aerosols exhibit a distinct chemical signature in urban/rural conditions, with NO3 : SO4 mass concentration ratios lower than for non-volcanic background aerosols. These results are supported by thermodynamic simulations of aerosol composition, using the ISORROPIA II model, which show that ammonium sulfate aerosols are preferentially formed at a high concentration of sulfate, leading to a decrease in the production of particulate ammonium nitrate. Such a chemical signature is however more difficult to identify at heavily polluted industrial sites due to a high level of background noise in sulfur. Nevertheless, aged volcanic sulfates can be distinguished from freshly emitted industrial sulfates according to their contrasting degree of anion neutralization. Combining AERONET (AErosol RObotic NETwork) sunphotometric data with ACSM observations, we also show a long persistence over weeks of pollution in volcanic sulfate aerosols, while SO2 pollution disappears in a few days at most. Finally, gathering 6-month long datasets from 27 sulfur monitoring stations of the EMEP (European Monitoring and Evaluation Programme) network allows us to demonstrate a much broader large-scale European pollution, in both SO2 and SO4, associated with the Holuhraun eruption, from Scandinavia to France. While widespread SO2 anomalies, with ground-level mass concentrations far exceeding background values, almost entirely result from the volcanic source, the origin of sulfate aerosols is more complex. Using a multi-site concentration-weighted trajectory analysis, emissions from the Holuhraun eruption are shown to be one of the main sources of SO4 at all EMEP sites across Europe and can be distinguished from anthropogenic emissions from eastern Europe but also from Great Britain. A wide variability in SO2 : SO4 mass concentration ratios, ranging from 0.8 to 8.0, is shown at several stations geographically dispersed at thousands of kilometres from the eruption site. Despite this apparent spatial complexity, we demonstrate that these mass oxidation ratios can be explained by a simple linear dependency on the age of the plume, with a SO2-to-SO4 oxidation rate of 0.23 h-1. Most current studies generally focus on SO2, an unambiguous and more readily measured marker of the volcanic plume. However, the long persistence of the chemical fingerprint of volcanic sulfate aerosols at continental scale, as shown for the Holuhraun eruption here, casts light on the impact of tropospheric eruptions and passive degassing activities on air quality, health, atmospheric chemistry and climate. © 2019 Author(s).
BibTeX:
@article{Boichu2019,
  author = {Boichu, Marie and Favez, Olivier and Riffault, Véronique and Petit, Jean-Eudes and Zhang, Yunjiang and Brogniez, Colette and Sciare, Jean and Chiapello, Isabelle and Clarisse, Lieven and Zhang, Shouwen and Pujol-Söhne, Nathalie and Tison, Emmanuel and Delbarre, Hervé and Goloub, Philippe},
  title = {Large-scale particulate air pollution and chemical fingerprint of volcanic sulfate aerosols from the 2014-2015 Holuhraun flood lava eruption of Bárdarbunga volcano (Iceland)},
  journal = {Atmospheric Chemistry and Physics},
  year = {2019},
  volume = {19},
  number = {22},
  pages = {14253 – 14287},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-19-14253-2019}
}
Bouche J, Bauduin S, Giuranna M, Robert S, Aoki S, Vandaele AC, Erwin JT, Daerden F, Wolkenberg P and Coheur P-F (2019), "Retrieval and characterization of carbon monoxide (CO) vertical profiles in the Martian atmosphere from observations of PFS/MEX", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 238
Abstract: The knowledge of the carbon monoxide (CO) abundance on Mars is essential in order to assess the processes driving the carbon cycle on the planet. Solar occultation measurements provide vertically-resolved measurements of CO from a few kilometers to higher altitudes and can be complemented by nadir measurements to enhance the spatial coverage of observations and the monitoring of the near-surface layer. Up to now, in the shortwave, CO retrievals from nadir observations have, however, mostly been performed on mean spectra and only total column abundances have been obtained. In this work we explore the possibility of exploiting nadir measurements from the Planetary Fourier Spectrometer (PFS) in the 1–0 band of CO (centered at 2143 cm−1) to retrieve vertical profiles of that species on individual measurement. The retrievals are performed for a set of 16 selected PFS spectra with reasonable signal-to-noise ratios by applying the Optimal Estimation Method (OEM) with appropriate constraints, built from model simulations of the Martian atmosphere. The retrieved profiles are characterized in terms of vertical sensitivity and errors. We demonstrate, in particular, that the PFS nadir measurements carry information mostly on the CO column below 15 km, with a maximum sensitivity to the near-surface atmosphere. These measurements allow to substantially reduce the prior uncertainty on the CO abundance in this altitude range, with an estimated total retrieval error on the column-averaged volume mixing ratio (VMR) around 10%. We show that the set of retrieved VMRs are in the range of values reported from other instruments. The retrieved VMRs also capture well the known spatial and seasonal CO variability, which is promising in the perspective of better exploiting the exceptional set of PFS observations on Mars. © 2019 Elsevier Ltd
BibTeX:
@article{Bouche2019,
  author = {Bouche, Jimmy and Bauduin, Sophie and Giuranna, Marco and Robert, Séverine and Aoki, Shohei and Vandaele, Ann Carine and Erwin, Justin T. and Daerden, Frank and Wolkenberg, Paulina and Coheur, Pierre-François},
  title = {Retrieval and characterization of carbon monoxide (CO) vertical profiles in the Martian atmosphere from observations of PFS/MEX},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2019},
  volume = {238},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2019.05.009}
}
Clarisse L, Clerbaux C, Franco B, Hadji-Lazaro J, Whitburn S, Kopp A, Hurtmans D and Coheur P-F (2019), "A Decadal Data Set of Global Atmospheric Dust Retrieved From IASI Satellite Measurements", Journal of Geophysical Research: Atmospheres. Vol. 124(3), pp. 1618 – 1647.
Abstract: Aerosol is an important component of the Earth's atmosphere, affecting weather, climate, and diverse elements of the biosphere. Satellite sounders are an essential tool for measuring the highly variable distributions of atmospheric aerosol. Here we present a new algorithm for estimating atmospheric dust optical depths and associated retrieval uncertainties from spectral radiance measurements of the Infrared Atmospheric Sounding Interferometer (IASI). The retrieval is based on the calculation of a dust index and on a neural network trained with synthetic IASI spectra. It has an inherent high sensitivity to dust and efficiently discriminates dust from other aerosols. In particular, over remote dust-free areas, the retrieved levels of optical depth have a low bias. Over sea, noise levels are markedly lower than over land. Performance over deserts is comparable to that of other land surfaces. We use ground-based coarse mode aerosol measurements from the AErosol RObotic NETwork to validate the new product. The overall assessment is favorable, with standard deviations in line with estimated uncertainties, low biases, and high correlation coefficients. However, a systematic relative bias occurs between sites dominated by African and Asian dust sources respectively, likely linked to differences in mineralogy. The retrieval has been performed on over a decade of IASI data, and the resulting data set is now publicly available. We present a global seasonal dust climatology based on this record and compare it with those obtained from independent satellite measurements (Moderate Resolution Imaging Spectroradiometer and a third-party IASI product) and dust optical depth from the ECMWF model. ©2019. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Clarisse2019b,
  author = {Clarisse, L. and Clerbaux, C. and Franco, B. and Hadji-Lazaro, J. and Whitburn, S. and Kopp, A.K. and Hurtmans, D. and Coheur, P.-F.},
  title = {A Decadal Data Set of Global Atmospheric Dust Retrieved From IASI Satellite Measurements},
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2019},
  volume = {124},
  number = {3},
  pages = {1618 – 1647},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2018JD029701}
}
Clarisse L, VanDamme M, Clerbaux C and Coheur P-F (2019), "Tracking down global NH3 point sources with wind-adjusted superresolution", Atmospheric Measurement Techniques. Vol. 12(10), pp. 5457 – 5473.
Abstract: As a precursor of atmospheric aerosols, ammonia (NH3) is one of the primary gaseous air pollutants. Given its short atmospheric lifetime, ambient NH3 concentrations are dominated by local sources. In a recent study, VanDamme et al. (2018) have highlighted the importance of NH3 point sources, especially those associated with feedlots and industrial ammonia production. Their emissions were shown to be largely underestimated in bottom-up emission inventories. The discovery was made possible thanks to the use of oversampling techniques applied to 9 years of global daily IASI NH3 satellite measurements. Oversampling allows one to increase the spatial resolution of averaged satellite data beyond what the satellites natively offer. Here we apply for the first time superresolution techniques, which are commonplace in many fields that rely on imaging, to measurements of an atmospheric sounder, whose images consist of just single pixels. We demonstrate the principle on synthetic data and on IASI measurements of a surface parameter. Superresolution is a priori less suitable to be applied on measurements of variable atmospheric constituents, in particular those affected by transport. However, by first applying the wind-rotation technique, which was introduced in the study of other primary pollutants, superresolution becomes highly effective in mapping NH3 at a very high spatial resolution. We show that plume transport can be revealed in greater detail than what was previously thought to be possible. Next, using this wind-adjusted superresolution technique, we introduce a new type of NH3 map that allows tracking down point sources more easily than the regular oversampled average. On a subset of known emitters, the source could be located within a median distance of 1.5&thinsp;km. We subsequently present a new global point-source catalog consisting of more than 500 localized and categorized point sources. Compared to our previous catalog, the number of identified sources more than doubled. In addition, we refined the classification of industries into five categories - fertilizer, coking, soda ash, geothermal and explosives industries - and introduced a new urban category for isolated NH3 hotspots over cities. The latter mainly consists of African megacities, as clear isolation of such urban hotspots is almost never possible elsewhere due to the presence of a diffuse background with higher concentrations. The techniques presented in this paper can most likely be exploited in the study of point sources of other short-lived atmospheric pollutants such as SO2 and NO2. © 2019. This work is distributed under the Creative Commons Attribution 4.0 License.
BibTeX:
@article{Clarisse2019a,
  author = {Clarisse, Lieven and VanDamme, Martin and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Tracking down global NH3 point sources with wind-adjusted superresolution},
  journal = {Atmospheric Measurement Techniques},
  year = {2019},
  volume = {12},
  number = {10},
  pages = {5457 – 5473},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-12-5457-2019}
}
Clarisse L, VanDamme M, Gardner W, Coheur P-F, Clerbaux C, Whitburn S, Hadji-Lazaro J and Hurtmans D (2019), " Atmospheric ammonia (NH 3 ) emanations from Lake Natron’s saline mudflats ", Scientific Reports. Vol. 9(1)
Abstract: In a recent global analysis of satellite-derived atmospheric NH 3 data, a hotspot was observed in the vicinity of Lake Natron, Tanzania. The lake is in the centre of an endorheic (limited drainage) basin and has shallow, saline-alkaline waters. Its remote location and the absence of nearby large anthropogenic sources suggest that the observed NH 3 is mainly of natural origin. Here we explore 10 years of IASI NH 3 satellite data and other publicly available datasets over the area to characterize the natural NH 3 emissions in this unique ecosystem. Temporal analysis reveals that the emissions are episodic and linked with the lake’s surface area. The largest NH 3 column loadings generally occur at the end of the dry season in September–November over Lake Natron’s largest mudflat, that is exposed with receding water levels. The timing is different from the agricultural dominated NH 3 emissions in the wider Natron area, which peak early in the year, after the first wet season. The likely source of NH 3 at Lake Natron is decomposition of organic material, either from rivers and springs or produced in the lake (plankton, bird excreta). High temperatures and alkalinity are known to promote NH 3 losses from soda lakes. We formulate six processes that may explain why the largest losses are observed specifically over concentrated brines and/or exposed sediments. As a by-product, we also show that hyperspectral infrared sounders such as IASI are capable of mapping different types of evaporative minerals such as trona and thermonatrite. © 2019, The Author(s).
BibTeX:
@article{Clarisse2019,
  author = {Clarisse, L. and VanDamme, M. and Gardner, W. and Coheur, P.-F. and Clerbaux, C. and Whitburn, S. and Hadji-Lazaro, J. and Hurtmans, D.},
  title = { Atmospheric ammonia (NH 3 ) emanations from Lake Natron’s saline mudflats },
  journal = {Scientific Reports},
  year = {2019},
  volume = {9},
  number = {1},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1038/s41598-019-39935-3}
}
Dammers E, McLinden CA, Griffin D, Shephard MW, Van Der Graaf S, Lutsch E, Schaap M, Gainairu-Matz Y, Fioletov V, VanDamme M, Whitburn S, Clarisse L, Cady-Pereira K, Clerbaux C, Francois Coheur P and Erisman JW (2019), "NH3 emissions from large point sources derived from CrIS and IASI satellite observations", Atmospheric Chemistry and Physics. Vol. 19(19), pp. 12261 – 12293.
Abstract: Ammonia (NH3) is an essential reactive nitrogen species in the biosphere and through its use in agriculture in the form of fertilizer (important for sustaining humankind). The current emission levels, however, are up to 4 times higher than in the previous century and continue to grow with uncertain consequences to human health and the environment. While NH3 at its current levels is a hazard to environmental and human health, the atmospheric budget is still highly uncertain, which is a product of an overall lack of measurements. The capability to measure NH3 with satellites has opened up new ways to study the atmospheric NH3 budget. In this study, we present the first estimates of NH3 emissions, lifetimes and plume widths from large (>∼ 5 kt yr-1) agricultural and industrial point sources from Cross-Track Infrared Sounder (CrIS) satellite observations across the globe with a consistent methodology. The same methodology is also applied to the Infrared Atmospheric Sounding Interferometer (IASI) (A and B) satellite observations, and we show that the satellites typically provide comparable results that are within the uncertainty of the estimates. The computed NH3 lifetime for large point sources is on average 2:35±1:16 h. For the 249 sources with emission levels detectable by the CrIS satellite, there are currently 55 locations missing (or underestimated by more than an order of magnitude) from the current Hemispheric Transport Atmospheric Pollution version 2 (HTAPv2) emission inventory and only 72 locations with emissions within a factor of 2 compared to the inventories. The CrIS emission estimates give a total of 5622 kt yr-1, for the sources analyzed in this study, which is around a factor of ∼ 2:5 higher than the emissions reported in HTAPv2. Furthermore, the study shows that it is possible to accurately detect short-and long-Term changes in emissions, demonstrating the possibility of using satellite-observed NH3 to constrain emission inventories. © 2019 Author(s).
BibTeX:
@article{Dammers2019,
  author = {Dammers, Enrico and McLinden, Chris A. and Griffin, Debora and Shephard, Mark W. and Van Der Graaf, Shelley and Lutsch, Erik and Schaap, Martijn and Gainairu-Matz, Yonatan and Fioletov, Vitali and VanDamme, Martin and Whitburn, Simon and Clarisse, Lieven and Cady-Pereira, Karen and Clerbaux, Cathy and Francois Coheur, Pierre and Erisman, Jan Willem},
  title = {NH3 emissions from large point sources derived from CrIS and IASI satellite observations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2019},
  volume = {19},
  number = {19},
  pages = {12261 – 12293},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-19-12261-2019}
}
Ekman J, Jönsson P, Godefroid M, Nazé C, Gaigalas G and Bieroń J (2019), "RIS 4: A program for relativistic isotope shift calculations", Computer Physics Communications. Vol. 235, pp. 433 – 446.
Abstract: Spectral lines from different isotopes display a small separation in energy, commonly referred to as the line isotope shift. The program RIS 4 (Relativistic Isotope Shift) calculates normal and specific mass shift parameters as well as field shift electronic factors from relativistic multiconfiguration Dirac–Hartree–Fock wave functions. These quantities, together with available nuclear data, determine isotope-dependent energy shifts. Using a reformulation of the field shift, it is possible to study, in a model-independent way, the atomic energy shifts arising from changes in nuclear charge distributions, e.g. deformations. Program summary: Program title: RIS 4 Program Files doi: http://dx.doi.org/10.17632/8vjpf69zch.1 Licensing provisions: MIT Programming language: Fortran 77 and Fortran 90 Journal reference of previous version: Comput. Phys. Comm. 184 (2013) 2187 Does the new version supersede the previous version?: Yes Subprograms used: GRASP 2K VERSION 1_1 Nature of problem: Prediction of level and transition isotope shifts in atoms using four-component relativistic wave functions. Solution method: The nuclear mass shifts and field shifts are treated using first order perturbation theory. The electron density and the normal and specific mass shift parameters can be expressed as [Formula presented], where [Formula presented] is the relevant operator and [Formula presented] is the configuration state expansion, where P, J and MJ are the parity and angular quantum numbers, respectively. The matrix elements, in turn, can be decomposed as sums over radial integrals multiplied by angular coefficients. The angular coefficients are calculated using routines from the GRASP2K VERSION 1_1 package [1]. Reasons for new version: This new version calculates field shift electronic factors resulting from non-constant (varying) electron densities inside the nucleus. Summary of revisions: This new version uses an expression of the field shift that through a polynomial expansion of the electron density contains higher order radial moments and thus takes the varying electron density within the nuclear volume into account. Restrictions: The complexity of the cases that can be handled is entirely determined by the GRASP2K package [1] used for the generation of the electronic wave functions. Unusual features: Using a reformulation of the field shift, it is possible to study the atomic energy shifts arising from changes in nuclear charge distributions, e.g. deformations. References: [1] P. Jönsson, G. Gaigalas, J. Bieroń, C. FroeseFischer, I.P. Grant, New version: Grasp2K relativistic atomic structure package, Comput. Phys. Commun. 184 (9) (2013) 2197–2203. © 2018
BibTeX:
@article{Ekman2019,
  author = {Ekman, J. and Jönsson, P. and Godefroid, M. and Nazé, C. and Gaigalas, G. and Bieroń, J.},
  title = {RIS 4: A program for relativistic isotope shift calculations},
  journal = {Computer Physics Communications},
  year = {2019},
  volume = {235},
  pages = {433 – 446},
  doi = {10.1016/j.cpc.2018.08.017}
}
Franco B, Clarisse L, Stavrakou T, Müller J-F, Pozzer A, Hadji-Lazaro J, Hurtmans D, Clerbaux C and Coheur P-F (2019), "Acetone Atmospheric Distribution Retrieved From Space", Geophysical Research Letters. Vol. 46(5), pp. 2884 – 2893.
Abstract: As one of the most abundant oxygenated volatile organic compounds in the atmosphere, acetone (CH3C[O]CH3) influences atmospheric oxidants levels and ozone formation. Here we report the first unambiguous identification of acetone from the nadir-viewing satellite sounder Infrared Atmospheric Sounding Interferometer (IASI). Via a neural network-based retrieval approach that was previously applied to the retrieval of other weak absorbers, we obtain daily global acetone retrievals. A first intercomparison with independent measurements is conducted. As the retrieval method is computationally fast, it allowed the full reprocessing of the 2007–2018 IASI time series. Analysis of the retrieved global product and its seasonality suggests that emissions of acetone and precursors from the terrestrial biosphere at Northern Hemisphere middle and high latitudes are the main contributors to the atmospheric acetone abundance, more than year-round oxidation of anthropogenic isoalkanes. Remarkably, biomass burning does not appear to be a strong global source of acetone. ©2019. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Franco2019,
  author = {Franco, B. and Clarisse, L. and Stavrakou, T. and Müller, J.-F. and Pozzer, A. and Hadji-Lazaro, J. and Hurtmans, D. and Clerbaux, C. and Coheur, P.-F.},
  title = {Acetone Atmospheric Distribution Retrieved From Space},
  journal = {Geophysical Research Letters},
  year = {2019},
  volume = {46},
  number = {5},
  pages = {2884 – 2893},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2019GL082052}
}
FroeseFischer C and Godefroid MR (2019), "Electron correlation in the lanthanides: 4f2 spectrum of Ce2+", Physical Review A. Vol. 99(3)
Abstract: Atoms and ions of lanthanides have multiple opens shells along with an open 4fk subshell. This paper studies the effect of electron correlation in such systems and how wave functions can be determined for the accurate prediction of atomic properties in the case of Ce2+ where k=2, using the multireference single- and double-excitation method. An efficient higher-order method is recommended for more reliable results. © 2019 American Physical Society.
BibTeX:
@article{FroeseFischer2019,
  author = {FroeseFischer, Charlotte and Godefroid, Michel R.},
  title = {Electron correlation in the lanthanides: 4f2 spectrum of Ce2+},
  journal = {Physical Review A},
  year = {2019},
  volume = {99},
  number = {3},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.99.032511}
}
Gans B, Boyé-Péronne S and Liévin J (2019), "Vibronic structure of the cyanobutadiyne cation. II. Theoretical exploration of the complex energy landscape of HC5N+", Journal of Chemical Physics. Vol. 150(24)
Abstract: The results of an extensive ab initio study of the cyanobutadiyne cation, initially motivated by threshold-photoelectron spectroscopy experiments [see the study by Gans et al., J. Chem. Phys. 150, 244304 (2019)], are reported in the present paper. Calculations at the internally contracted multireference configuration interaction level of theory have been performed to derive the rovibronic properties of the seven lowest electronic states of HC5N+. Equilibrium geometries, rotational constants, vibrational frequencies, electric dipole moments, and spin-orbit constants have been calculated and compared with experimental data when available. Adiabatic and vertical ionization energies from the neutral ground state as well as transition energies within the cation electronic manifold are predicted, using the convergence to the complete basis set limit. The accurate description of the complex energy landscape up to 32 000 cm-1 above the ionization potential allows us to perform Franck-Condon simulations of the photoionization spectrum to the X+ 2Π, A+ 2Π, B+ 2ς+, and C+ 2Π states and allows us to simulate the A+ 2Π → X+ 2Π emission spectrum. The vibronic perturbations occurring on the excited potential energy surfaces are revealed and discussed, in particular, for the 3 2Π surface, which presents a double-well topography. © 2019 Author(s).
BibTeX:
@article{Gans2019a,
  author = {Gans, Bérenger and Boyé-Péronne, Séverine and Liévin, Jacques},
  title = {Vibronic structure of the cyanobutadiyne cation. II. Theoretical exploration of the complex energy landscape of HC5N+},
  journal = {Journal of Chemical Physics},
  year = {2019},
  volume = {150},
  number = {24},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/1.5097691}
}
Gans B, Lamarre N, Guillemin J-C, Douin S, Alcaraz C, Romanzin C, Garcia GA, Liévin J and Boyé-Péronne S (2019), "Vibronic structure of the cyanobutadiyne cation. I. VUV photoionization study of HC5N", Journal of Chemical Physics. Vol. 150(24)
Abstract: We report the vacuum-ultraviolet threshold-photoelectron spectrum of HC5N recorded over a wide spectral range, from 84 000 to 120 000 cm-1, with a 120 cm-1 spectral resolution, better than what was achieved in previous photoelectron studies, and with mass selectivity. The adiabatic ionization potential of cyanobutadiyne is measured at 85 366 (±40) cm-1. Assignment of the vibrational bands of the four lowest electronic states X+2Π, A+2Π, B+2ς+, and C+2Π are performed, supported by high level ab initio calculations which are fully detailed in Paper II [B. Gans et al., J. Chem. Phys. 150, 244303 (2019)] and by Franck-Condon simulations. Only vibrational stretching modes are observed in the threshold-photoelectron spectra. The ground state of HC5N+ exhibits a vibrational progression in the ν2 stretching mode involving mainly the elongation of the CC triple bonds, whereas the A+ and C+ excited electronic states show a progression in the stretching mode mainly associated with the elongation of the CN bond, i.e., ν4 and ν3, respectively. The B+ state appears almost as a vibrationless structure in close vicinity to the A+ state. © 2019 Author(s).
BibTeX:
@article{Gans2019,
  author = {Gans, Bérenger and Lamarre, Nicolas and Guillemin, Jean-Claude and Douin, Stéphane and Alcaraz, Christian and Romanzin, Claire and Garcia, Gustavo A. and Liévin, Jacques and Boyé-Péronne, Séverine},
  title = {Vibronic structure of the cyanobutadiyne cation. I. VUV photoionization study of HC5N},
  journal = {Journal of Chemical Physics},
  year = {2019},
  volume = {150},
  number = {24},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/1.5097688}
}
Georges R, Thiévin J, Benidar A, Carles S, Amyay B, Louviot M, Boudon V and VanderAuwera J (2019), "High enthalpy source dedicated to quantitative infrared emission spectroscopy of gas flows at elevated temperatures", Review of Scientific Instruments. Vol. 90(9)
Abstract: The High Enthalpy Source (HES) is a novel high temperature source developed to measure infrared line-by-line integrated absorption cross sections of flowing gases up to 2000 K. The HES relies on a porous graphite furnace designed to uniformly heat a constant flow of gas. The flow compensates thermal dissociation by renewing continuously the gas sample and eliminating dissociation products. The flowing characteristics have been investigated using computational fluid dynamics simulation confirming good temperature uniformity. The HES has been coupled to a high-resolution Fourier transform spectrometer to record emission spectra of methane at temperatures ranging between 700 and 1400 K. A radiative model has been developed to extract absolute line intensities from the recorded spectra. © 2019 Author(s).
BibTeX:
@article{Georges2019,
  author = {Georges, R. and Thiévin, J. and Benidar, A. and Carles, S. and Amyay, B. and Louviot, M. and Boudon, V. and VanderAuwera, J.},
  title = {High enthalpy source dedicated to quantitative infrared emission spectroscopy of gas flows at elevated temperatures},
  journal = {Review of Scientific Instruments},
  year = {2019},
  volume = {90},
  number = {9},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/1.5097696}
}
Hedelt P, Efremenko DS, Loyola DG, Spurr R and Clarisse L (2019), "Sulfur dioxide layer height retrieval from Sentinel-5 Precursor/TROPOMI using FP_ILM", Atmospheric Measurement Techniques. Vol. 12(10), pp. 5503 – 5517.
Abstract: The accurate determination of the location, height, and loading of sulfur dioxide (SO2) plumes emitted by volcanic eruptions is essential for aviation safety. The SO2 layer height is also one of the most critical parameters with respect to determining the impact on the climate. Retrievals of SO2 plume height have been carried out using satellite UV backscatter measurements, but, until now, such algorithms are very time-consuming. We have developed an extremely fast yet accurate SO2 layer height retrieval using the Full-Physics Inverse Learning Machine (FP_ILM) algorithm. This is the first time the algorithm has been applied to measurements from the TROPOMI instrument onboard the Sentinel-5 Precursor platform. In this paper, we demonstrate the ability of the FP_ILM algorithm to retrieve SO2 plume layer heights in near-real-time applications with an accuracy of better than 2&thinsp;km for SO2 total columns larger than 20&thinsp;DU. We present SO2 layer height results for the volcanic eruptions of Sinabung in February 2018, Sierra Negra in June 2018, and Raikoke in June 2019, observed by TROPOMI. © 2019 BMJ Publishing Group. All rights reserved.
BibTeX:
@article{Hedelt2019,
  author = {Hedelt, Pascal and Efremenko, Dmitry S. and Loyola, Diego G. and Spurr, Robert and Clarisse, Lieven},
  title = {Sulfur dioxide layer height retrieval from Sentinel-5 Precursor/TROPOMI using FP_ILM},
  journal = {Atmospheric Measurement Techniques},
  year = {2019},
  volume = {12},
  number = {10},
  pages = {5503 – 5517},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-12-5503-2019}
}
Hillenbrand P-M, Bowen K, Liévin J, Urbain X and Savin D (2019), "Experimental and Theoretical Studies of the Isotope Exchange Reaction D + H3 + → H2D+ + H", Astrophysical Journal. Vol. 877(1)
Abstract: Deuterated molecules are important chemical tracers of prestellar and protostellar cores. Up to now, the titular reaction has been assumed to contribute to the generation of these deuterated molecules. We have measured the merged-beams rate coefficient for this reaction as a function of the relative collision energy in the range of about 10meV-10 eV. By varying the internal temperature of the reacting H+ 3 molecules, we found indications for the existence of a reaction barrier. We have performed detailed theoretical calculations for the zero-point-corrected energy profile of the reaction and determined a new value for the barrier height of ≈68 meV. Furthermore, we have calculated the tunneling probability through the barrier. Our experimental and theoretical results show that the reaction is essentially closed at astrochemically relevant temperatures. We derive a thermal rate coefficient of <1 × 10-12 cm3 s-1 for temperatures below 75 K with tunneling effects included and below 155 K without tunneling. © 2019. The American Astronomical Society. All rights reserved.
BibTeX:
@article{Hillenbrand2019,
  author = {Hillenbrand, P.-M. and Bowen, K.P. and Liévin, J. and Urbain, X. and Savin, D.W.},
  title = {Experimental and Theoretical Studies of the Isotope Exchange Reaction D + H3 + → H2D+ + H},
  journal = {Astrophysical Journal},
  year = {2019},
  volume = {877},
  number = {1},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.3847/1538-4357/ab16dc}
}
Kas M, Loreau J, Liévin J and Vaeck N (2019), "Cold reactive and nonreactive collisions of Li and Rb with C2-: Implications for hybrid-trap experiments", Physical Review A. Vol. 99(4)
Abstract: We present a theoretical investigation of cold reactive and nonreactive collisions of Li and Rb atoms with C2-. The potential energy surfaces for the singlet and triplet states of the Li-C2- and Rb-C2- systems have been obtained using the CASSCF followed by ic-MRCI approach with extended basis sets. The potential energy surfaces are then used to investigate the associative detachment reaction and to calculate rotationally inelastic cross sections at low collision energies by means of the close-coupling method. The results are compared to those obtained for other anionic systems such as Rb-OH-, and the implications for hybrid-trap experiments and sympathetic cooling experiments are explored. Furthermore, we discuss the possibility to perform Doppler thermometry on the C2- anion and investigate the collision process involving excited electronic states. © 2019 American Physical Society.
BibTeX:
@article{Kas2019,
  author = {Kas, Milaim and Loreau, Jérôme and Liévin, Jacques and Vaeck, Nathalie},
  title = {Cold reactive and nonreactive collisions of Li and Rb with C2-: Implications for hybrid-trap experiments},
  journal = {Physical Review A},
  year = {2019},
  volume = {99},
  number = {4},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.99.042702}
}
Kas M, Loreau J, Liévin J and Vaeck N (2019), "Reactivity of Hydrated Hydroxide Anion Clusters with H and Rb: An ab Initio Study", Journal of Physical Chemistry A. Vol. 123(41), pp. 8893 – 8906.
Abstract: We present a theoretical investigation of the hydrated hydroxide anion clusters, OH(H2O)n-, and of the collisional complexes, H-OH(H2O)n- and Rb-OH(H2O)n- (with n = 1-4). The MP2 and CCSD(T) methods are used to calculate interaction energies, optimized geometries, and vertical detachment energies. Parts of the potential energy surfaces are explored with a focus on the autodetachment region. We point out the importance of diffuse functions to correctly describe the latter. We use our results to discuss the different water loss and electronic detachment channels, which are the main reaction routes at room temperature and below. In particular, we have considered a direct and an indirect process for the electronic detachment, depending on whether water loss follows or precedes the detachment of the excess electron. We use our results to discuss the implications for astrochemistry and hybrid trap experiments in the context of cold chemistry. © 2019 American Chemical Society.
BibTeX:
@article{Kas2019a,
  author = {Kas, Milaim and Loreau, Jérôme and Liévin, Jacques and Vaeck, Nathalie},
  title = {Reactivity of Hydrated Hydroxide Anion Clusters with H and Rb: An ab Initio Study},
  journal = {Journal of Physical Chemistry A},
  year = {2019},
  volume = {123},
  number = {41},
  pages = {8893 – 8906},
  note = {All Open Access, Green Open Access},
  doi = {10.1021/acs.jpca.9b05971}
}
Korablev O, Vandaele AC, Montmessin F, Fedorova AA, Trokhimovskiy A, Forget F, Lefèvre F, Daerden F, Thomas IR, Trompet L, Erwin JT, Aoki S, Robert S, Neary L, Viscardy S, Grigoriev AV, Ignatiev NI, Shakun A, Patrakeev A, Belyaev DA, Bertaux J-L, Olsen KS, Baggio L, Alday J, Ivanov YS, Ristic B, Mason J, Willame Y, Depiesse C, Hetey L, Berkenbosch S, Clairquin R, Queirolo C, Beeckman B, Neefs E, Patel MR, Bellucci G, López-Moreno J-J, Wilson CF, Etiope G, Zelenyi L, Svedhem H, Vago JL, Alonso-Rodrigo G, Altieri F, Anufreychik K, Arnold G, Bauduin S, Bolsée D, Carrozzo G, Clancy RT, Cloutis E, Crismani M, Da Pieve F, D’Aversa E, Duxbury N, Encrenaz T, Fouchet T, Funke B, Fussen D, Garcia-Comas M, Gérard J-C, Giuranna M, Gkouvelis L, Gonzalez-Galindo F, Grassi D, Guerlet S, Hartogh P, Holmes J, Hubert B, Kaminski J, Karatekin O, Kasaba Y, Kass D, Khatuntsev I, Kleinböhl A, Kokonkov N, Krasnopolsky V, Kuzmin R, Lacombe G, Lanciano O, Lellouch E, Lewis S, Luginin M, Liuzzi G, López-Puertas M, López-Valverde M, Määttänen A, Mahieux A, Marcq E, Martin-Torres J, Maslov I, Medvedev A, Millour E, Moshkin B, Mumma M, Nakagawa H, Novak RE, Oliva F, Patsaev D, Piccialli A, Quantin-Nataf C, Renotte E, Ritter B, Rodin A, Schmidt F, Schneider N, Shematovich V, Smith M, Teanby NA, Thiemann E, Thomas N, VanderAuwera J, Vazquez L, Villanueva G, Vincendon M, Whiteway J, Wilquet V, Wolff MJ, Wolkenberg P, Yelle R, Young R, Zasova L and Zorzano MP (2019), "No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations", Nature. Vol. 568(7753), pp. 517 – 520.
Abstract: The detection of methane on Mars has been interpreted as indicating that geochemical or biotic activities could persist on Mars today1. A number of different measurements of methane show evidence of transient, locally elevated methane concentrations and seasonal variations in background methane concentrations2–5. These measurements, however, are difficult to reconcile with our current understanding of the chemistry and physics of the Martian atmosphere6,7, which—given methane’s lifetime of several centuries—predicts an even, well mixed distribution of methane1,6,8. Here we report highly sensitive measurements of the atmosphere of Mars in an attempt to detect methane, using the ACS and NOMAD instruments onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter from April to August 2018. We did not detect any methane over a range of latitudes in both hemispheres, obtaining an upper limit for methane of about 0.05 parts per billion by volume, which is 10 to 100 times lower than previously reported positive detections2,4. We suggest that reconciliation between the present findings and the background methane concentrations found in the Gale crater4 would require an unknown process that can rapidly remove or sequester methane from the lower atmosphere before it spreads globally. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
BibTeX:
@article{Korablev2019a,
  author = {Korablev, Oleg and Vandaele, Ann Carine and Montmessin, Franck and Fedorova, Anna A. and Trokhimovskiy, Alexander and Forget, François and Lefèvre, Franck and Daerden, Frank and Thomas, Ian R. and Trompet, Loïc and Erwin, Justin T. and Aoki, Shohei and Robert, Séverine and Neary, Lori and Viscardy, Sébastien and Grigoriev, Alexey V. and Ignatiev, Nikolay I. and Shakun, Alexey and Patrakeev, Andrey and Belyaev, Denis A. and Bertaux, Jean-Loup and Olsen, Kevin S. and Baggio, Lucio and Alday, Juan and Ivanov, Yuriy S. and Ristic, Bojan and Mason, Jon and Willame, Yannick and Depiesse, Cédric and Hetey, Laszlo and Berkenbosch, Sophie and Clairquin, Roland and Queirolo, Claudio and Beeckman, Bram and Neefs, Eddy and Patel, Manish R. and Bellucci, Giancarlo and López-Moreno, Jose-Juan and Wilson, Colin F. and Etiope, Giuseppe and Zelenyi, Lev and Svedhem, Håkan and Vago, Jorge L. and Alonso-Rodrigo, Gustavo and Altieri, Francesca and Anufreychik, Konstantin and Arnold, Gabriele and Bauduin, Sophie and Bolsée, David and Carrozzo, Giacomo and Clancy, R. Todd and Cloutis, Edward and Crismani, Matteo and Da Pieve, Fabiana and D’Aversa, Emiliano and Duxbury, Natalia and Encrenaz, Therese and Fouchet, Thierry and Funke, Bernd and Fussen, Didier and Garcia-Comas, Maia and Gérard, Jean-Claude and Giuranna, Marco and Gkouvelis, Leo and Gonzalez-Galindo, Francisco and Grassi, Davide and Guerlet, Sandrine and Hartogh, Paul and Holmes, James and Hubert, Benoît and Kaminski, Jacek and Karatekin, Ozgur and Kasaba, Yasumasa and Kass, David and Khatuntsev, Igor and Kleinböhl, Armin and Kokonkov, Nikita and Krasnopolsky, Vladimir and Kuzmin, Ruslan and Lacombe, Gaétan and Lanciano, Orietta and Lellouch, Emmanuel and Lewis, Stephen and Luginin, Mikhail and Liuzzi, Giuliano and López-Puertas, Manuel and López-Valverde, Miguel and Määttänen, Anni and Mahieux, Arnaud and Marcq, Emmanuel and Martin-Torres, Javier and Maslov, Igor and Medvedev, Alexander and Millour, Ehouarn and Moshkin, Boris and Mumma, Michael J. and Nakagawa, Hiromu and Novak, Robert E. and Oliva, Fabrizio and Patsaev, Dmitry and Piccialli, Arianna and Quantin-Nataf, Cathy and Renotte, Etienne and Ritter, Birgit and Rodin, Alexander and Schmidt, Frédéric and Schneider, Nick and Shematovich, Valery and Smith, Michael D. and Teanby, Nicholas A. and Thiemann, Ed and Thomas, Nicolas and VanderAuwera, Jean and Vazquez, Luis and Villanueva, Geronimo and Vincendon, Matthieu and Whiteway, James and Wilquet, Valérie and Wolff, Michael J. and Wolkenberg, Paulina and Yelle, Roger and Young, Roland and Zasova, Ludmila and Zorzano, Maria Paz},
  title = {No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations},
  journal = {Nature},
  year = {2019},
  volume = {568},
  number = {7753},
  pages = {517 – 520},
  note = {All Open Access, Green Open Access},
  doi = {10.1038/s41586-019-1096-4}
}
Korablev O, Vandaele AC, Montmessin F, Fedorova AA, Trokhimovskiy A, Forget F, Lefèvre F, Daerden F, Thomas IR, Trompet L, Erwin JT, Aoki S, Robert S, Neary L, Viscardy S, Grigoriev AV, Ignatiev NI, Shakun A, Patrakeev A, Belyaev DA, Bertaux J-L, Olsen KS, Baggio L, Alday J, Ivanov YS, Ristic B, Mason J, Willame Y, Depiesse C, Hetey L, Berkenbosch S, Clairquin R, Queirolo C, Beeckman B, Neefs E, Patel MR, Bellucci G, López-Moreno J-J, Wilson CF, Etiope G, Zelenyi L, Svedhem H, Vago JL, Alonso-Rodrigo G, Altieri F, Anufreychik K, Arnold G, Bauduin S, Bolsée D, Carrozzo G, Clancy RT, Cloutis E, Crismani M, Da Pieve F, D’Aversa E, Duxbury N, Encrenaz T, Fouchet T, Funke B, Fussen D, Garcia-Comas M, Gérard J-C, Giuranna M, Gkouvelis L, Gonzalez-Galindo F, Grassi D, Guerlet S, Hartogh P, Holmes J, Hubert B, Kaminski J, Karatekin O, Kasaba Y, Kass D, Khatuntsev I, Kleinböhl A, Kokonkov N, Krasnopolsky V, Kuzmin R, Lacombe G, Lanciano O, Lellouch E, Lewis S, Luginin M, Liuzzi G, López-Puertas M, López-Valverde M, Määttänen A, Mahieux A, Marcq E, Martin-Torres J, Maslov I, Medvedev A, Millour E, Moshkin B, Mumma MJ, Nakagawa H, Novak RE, Oliva F, Patsaev D, Piccialli A, Quantin-Nataf C, Renotte E, Ritter B, Rodin A, Schmidt F, Schneider N, Shematovich V, Smith MD, Teanby NA, Thiemann E, Thomas N, VanderAuwera J, Vazquez L, Villanueva G, Vincendon M, Whiteway J, Wilquet V, Wolff MJ, Wolkenberg P, Yelle R, Young R, Zasova L and Zorzano MP (2019), "Publisher Correction: No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations (Nature, (2019), 568, 7753, (517-520), 10.1038/s41586-019-1096-4)", Nature. Vol. 569(7754), pp. E2.
Abstract: The surname of author Cathy Quantin-Nataf was misspelled ‘Quantin-Nata’, authors Ehouarn Millour and Roland Young were missing from the ACS and NOMAD Science Teams list, and minor changes have been made to the author and affiliation lists; see accompanying Amendment. These errors have been corrected online. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
BibTeX:
@article{Korablev2019,
  author = {Korablev, Oleg and Vandaele, Ann Carine and Montmessin, Franck and Fedorova, Anna A. and Trokhimovskiy, Alexander and Forget, François and Lefèvre, Franck and Daerden, Frank and Thomas, Ian R. and Trompet, Loïc and Erwin, Justin T. and Aoki, Shohei and Robert, Séverine and Neary, Lori and Viscardy, Sébastien and Grigoriev, Alexey V. and Ignatiev, Nikolay I. and Shakun, Alexey and Patrakeev, Andrey and Belyaev, Denis A. and Bertaux, Jean-Loup and Olsen, Kevin S. and Baggio, Lucio and Alday, Juan and Ivanov, Yuriy S. and Ristic, Bojan and Mason, Jon and Willame, Yannick and Depiesse, Cédric and Hetey, Laszlo and Berkenbosch, Sophie and Clairquin, Roland and Queirolo, Claudio and Beeckman, Bram and Neefs, Eddy and Patel, Manish R. and Bellucci, Giancarlo and López-Moreno, Jose-Juan and Wilson, Colin F. and Etiope, Giuseppe and Zelenyi, Lev and Svedhem, Håkan and Vago, Jorge L. and Alonso-Rodrigo, Gustavo and Altieri, Francesca and Anufreychik, Konstantin and Arnold, Gabriele and Bauduin, Sophie and Bolsée, David and Carrozzo, Giacomo and Clancy, R. Todd and Cloutis, Edward and Crismani, Matteo and Da Pieve, Fabiana and D’Aversa, Emiliano and Duxbury, Natalia and Encrenaz, Therese and Fouchet, Thierry and Funke, Bernd and Fussen, Didier and Garcia-Comas, Maia and Gérard, Jean-Claude and Giuranna, Marco and Gkouvelis, Leo and Gonzalez-Galindo, Francisco and Grassi, Davide and Guerlet, Sandrine and Hartogh, Paul and Holmes, James and Hubert, Benoît and Kaminski, Jacek and Karatekin, Ozgur and Kasaba, Yasumasa and Kass, David and Khatuntsev, Igor and Kleinböhl, Armin and Kokonkov, Nikita and Krasnopolsky, Vladimir and Kuzmin, Ruslan and Lacombe, Gaétan and Lanciano, Orietta and Lellouch, Emmanuel and Lewis, Stephen and Luginin, Mikhail and Liuzzi, Giuliano and López-Puertas, Manuel and López-Valverde, Miguel and Määttänen, Anni and Mahieux, Arnaud and Marcq, Emmanuel and Martin-Torres, Javier and Maslov, Igor and Medvedev, Alexander and Millour, Ehouarn and Moshkin, Boris and Mumma, Michael J. and Nakagawa, Hiromu and Novak, Robert E. and Oliva, Fabrizio and Patsaev, Dmitry and Piccialli, Arianna and Quantin-Nataf, Cathy and Renotte, Etienne and Ritter, Birgit and Rodin, Alexander and Schmidt, Frédéric and Schneider, Nick and Shematovich, Valery and Smith, Michael D. and Teanby, Nicholas A. and Thiemann, Ed and Thomas, Nicolas and VanderAuwera, Jean and Vazquez, Luis and Villanueva, Geronimo and Vincendon, Matthieu and Whiteway, James and Wilquet, Valérie and Wolff, Michael J. and Wolkenberg, Paulina and Yelle, Roger and Young, Roland and Zasova, Ludmila and Zorzano, Maria Paz},
  title = {Publisher Correction: No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations (Nature, (2019), 568, 7753, (517-520), 10.1038/s41586-019-1096-4)},
  journal = {Nature},
  year = {2019},
  volume = {569},
  number = {7754},
  pages = {E2},
  note = {All Open Access, Bronze Open Access},
  doi = {10.1038/s41586-019-1164-9}
}
Kwabia-Tchana F, Attafi Y, Manceron L, Doizi D, VanderAuwera J and Perrin A (2019), "Line intensities for the ν6 and 2ν3 bands of methyl iodide (12CH3I)", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 222-223, pp. 130 – 137.
Abstract: The goal of this study is to measure for the first time absolute line intensities for the ν6 band of methyl iodide (CH3I) centered at 892.918 cm–1. High-resolution Fourier transform spectra were recorded at various pressures for the whole 500–1450 cm–1 spectral range. Using these spectra, a large set of CH3I individual line intensities was measured for the ν6 band. These experimental intensities were least squares fitted to derive the expansion of the ν6 transition moment operator. The theoretical model used to describe the line positions and intensities accounts for the hyperfine structure in the 61 and ground states and for the vibration-rotation resonances that couple the 61 energy levels with those of the 32 and 21 vibrational states [Perrin et al., J. Mol. Spectrosc. 324 (2016) 28–35]. As the 2ν3 band is extremely weak, its associated transition moment operator was estimated from band strength available in the literature. A comprehensive list of line positions and intensities was generated for the ν6 and 2ν3 bands of CH3I at 11 µm, which should be useful for the possible detection of this species by the future IASI-NG satellite instrument (Infrared Atmospheric Sounding Interferometer New Generation), now under preparation (https://iasi-ng.cnes.fr/en/IASI-NG/index.htm). © 2018
BibTeX:
@article{KwabiaTchana2019,
  author = {Kwabia-Tchana, F. and Attafi, Y. and Manceron, L. and Doizi, D. and VanderAuwera, J. and Perrin, A.},
  title = {Line intensities for the ν6 and 2ν3 bands of methyl iodide (12CH3I)},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2019},
  volume = {222-223},
  pages = {130 – 137},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2018.10.001}
}
Lachatre M, Fortems-Cheiney A, Foret G, Siour G, Dufour G, Clarisse L, Clerbaux C, Coheur P-F, VanDamme M and Beekmann M (2019), "The unintended consequence of SO2 and NO2 regulations over China: Increase of ammonia levels and impact on PM2.5 concentrations", Atmospheric Chemistry and Physics. Vol. 19(10), pp. 6701 – 6716.
Abstract: Air pollution reaching hazardous levels in many Chinese cities has been a major concern in China over the past decades. New policies have been applied to regulate anthropogenic pollutant emissions, leading to changes in atmospheric composition and in particulate matter (PM) production. Increasing levels of atmospheric ammonia columns have been observed by satellite during recent years. In particular, observations from the Infrared Atmospheric Sounding Interferometer (IASI) reveal an increase of these columns by 15% and 65% from 2011 to 2013 and 2015, respectively, over eastern China. In this paper we performed model simulations for 2011, 2013 and 2015 in order to understand the origin of this increase and to quantify the link between ammonia and the inorganic components of particles: NHC+4(p)/SO2-4(p)/NO-3(p). Interannual change of meteorology can be excluded as a reason: year 2015 meteorology leads to enhanced sulfate production over eastern China, which increases the ammonium and decreases the ammonia content, which is contrary to satellite observations. Reductions in SO2 and NOx emissions from 2011 to 2015 of 37.5% and 21% respectively, as constrained from satellite data, lead to decreased inorganic matter (by 14% for NH+4(p) +SO2-4(p) + NO-3(p)). This in turn leads to increased gaseous NH3(g) tropospheric columns by as much as 24% and 49% (sampled corresponding to IASI data availability) from 2011 to 2013 and 2015 respectively and thus can explain most of the observed increase. © Author(s) 2019.
BibTeX:
@article{Lachatre2019,
  author = {Lachatre, Mathieu and Fortems-Cheiney, Audrey and Foret, Gilles and Siour, Guillaume and Dufour, Gaëlle and Clarisse, Lieven and Clerbaux, Cathy and Coheur, Pierre-François and VanDamme, Martin and Beekmann, Matthias},
  title = {The unintended consequence of SO2 and NO2 regulations over China: Increase of ammonia levels and impact on PM2.5 concentrations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2019},
  volume = {19},
  number = {10},
  pages = {6701 – 6716},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-19-6701-2019}
}
Launoy T, Loreau J, Dochain A, Liévin J, Vaeck N and Urbain X (2019), "Mutual Neutralization in Li+-D- Collisions: A Combined Experimental and Theoretical Study", Astrophysical Journal. Vol. 883(1)
Abstract: We present a combined experimental and theoretical study of the mutual neutralization (MN) process in collisions of lithium ions (Li+) with deuterium anions (D-) at collision energies below 1 eV. We employ a merged-beam apparatus to determine total and state-to-state MN cross sections. We perform nuclear dynamics calculations using the multichannel Landau-Zener model based on accurate ab initio molecular data. We obtain an excellent agreement between the experimental and theoretical results over the energy range covered in this work. We show that the basis sets used in the ab initio calculations have a limited influence on the total cross section, but strongly impacts the results obtained for the partial cross sections or the reaction branching ratios. This demonstrates the important role of high-precision measurements to validate the theoretical approaches used to study gas-phase reactive processes. Finally, we compute MN rate coefficients for Li+ + H- and Li+ + D-, and discuss their significance for astrochemistry models. © 2019. The American Astronomical Society. All rights reserved.
BibTeX:
@article{Launoy2019,
  author = {Launoy, Thibaut and Loreau, Jérôme and Dochain, Arnaud and Liévin, Jacques and Vaeck, Nathalie and Urbain, Xavier},
  title = {Mutual Neutralization in Li+-D- Collisions: A Combined Experimental and Theoretical Study},
  journal = {Astrophysical Journal},
  year = {2019},
  volume = {883},
  number = {1},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.3847/1538-4357/ab3346}
}
Liuzzi G, Villanueva GL, Mumma MJ, Smith MD, Daerden F, Ristic B, Thomas I, Vandaele AC, Patel MR, Lopez-Moreno J-J, Bellucci G, Allen M, Alonso-Rodrigo G, Altieri F, Aoki S, Bauduin S, Bolsée D, Clancy T, Cloutis E, D'Aversa E, Depiesse C, Erwin J, Fedorova A, Formisano V, Funke B, Fussen D, Garcia-Comas M, Geminale A, Gérard J-C, Gillotay D, Giuranna M, Gonzalez-Galindo F, Hewson W, Homes J, Ignatiev N, Kaminski J, Karatekin O, Kasaba Y, Lanciano O, Lefèvre F, Lewis S, López-Puertas M, López-Valverde M, Mahieux A, Mason J, Mc Connell J, Hiromu Neary Nakagawa L, Neefs E, Novak R, Oliva F, Piccialli A, Renotte E, Robert S, Sindoni G, Stiepen A, Trokhimovskiy A, VanderAuwera J, Viscardy S, Whiteway J, Willame Y, Wilquet V, Wolff M, Wolkenberg P, Aparicio del Moral B, Barzin P, Beeckman B, BenMoussa A, Berkenbosch S, Biondi D, Bonnewijn S, Candini GP, Clairquin R, Cubas J, Giordanengo B, Gissot S, Gomez A, Hathi B, Jeronimo Zafra J, Leese M, Maes J, Mazy E, Mazzoli A, Meseguer J, Morales R, Orban A, Pastor-Morales M, Perez-grande I, Queirolo C, Rodriguez Gomez J, Saggin B, Samain V, Sanz Andres A, Sanz R, Simar J-F and Thibert T (2019), "Methane on Mars: New insights into the sensitivity of CH4 with the NOMAD/ExoMars spectrometer through its first in-flight calibration", Icarus. Vol. 321, pp. 671 – 690.
Abstract: The Nadir and Occultation for MArs Discovery instrument (NOMAD), onboard the ExoMars Trace Gas Orbiter (TGO) spacecraft was conceived to observe Mars in solar occultation, nadir, and limb geometries, and will be able to produce an outstanding amount of diverse data, mostly focused on properties of the atmosphere. The infrared channels of the instrument operate by combining an echelle grating spectrometer with an Acousto-Optical Tunable Filter (AOTF). Using in-flight data, we characterized the instrument performance and parameterized its calibration. In particular: an accurate frequency calibration was achieved, together with its variability due to thermal effects on the grating. The AOTF properties and transfer function were also quantified, and we developed and tested a realistic method to compute the spectral continuum transmitted through the coupled grating and AOTF system. The calibration results enabled unprecedented insights into the important problem of the sensitivity of NOMAD to methane abundances in the atmosphere. We also deeply characterized its performance under realistic conditions of varying aerosol abundances, diverse albedos and changing illumination conditions as foreseen over the nominal mission. The results show that, in low aerosol conditions, NOMAD single spectrum, 1σ sensitivity to CH4 is around 0.33 ppbv at 20 km of altitude when performing solar occultations, and better than 1 ppbv below 30 km. In dusty conditions, we show that the sensitivity drops to 0 below 10 km. In Nadir geometry, results demonstrate that NOMAD will be able to produce seasonal maps of CH4 with a sensitivity around 5 ppbv over most of planet's surface with spatial integration over 5 × 5° bins. Results show also that such numbers can be improved by a factor of  10 to  30 by data binning. Overall, our results quantify NOMAD's capability to address the variable aspects of Martian climate. © 2018 Elsevier Inc.
BibTeX:
@article{Liuzzi2019,
  author = {Liuzzi, Giuliano and Villanueva, Geronimo L. and Mumma, Michael J. and Smith, Michael D. and Daerden, Frank and Ristic, Bojan and Thomas, Ian and Vandaele, Ann Carine and Patel, Manish R. and Lopez-Moreno, José-Juan and Bellucci, Giancarlo and Allen, Mark and Alonso-Rodrigo, Gustavo and Altieri, Francesca and Aoki, Shohei and Bauduin, Sophie and Bolsée, David and Clancy, Todd and Cloutis, Edward and D'Aversa, Emiliano and Depiesse, Cédric and Erwin, Justin and Fedorova, Anna and Formisano, Vittorio and Funke, Bernd and Fussen, Didier and Garcia-Comas, Maia and Geminale, Anna and Gérard, Jean-Claude and Gillotay, Didier and Giuranna, Marco and Gonzalez-Galindo, Francisco and Hewson, Will and Homes, James and Ignatiev, Nicolai and Kaminski, Jacek and Karatekin, Ozgur and Kasaba, Yasumasa and Lanciano, Orietta and Lefèvre, Franck and Lewis, Stephen and López- Puertas, Manuel and López-Valverde, Miguel and Mahieux, Arnaud and Mason, Jon and Mc Connell, Jack and Hiromu Neary Nakagawa, Lori and Neefs, Eddy and Novak, R. and Oliva, Fabrizio and Piccialli, Arianna and Renotte, Etienne and Robert, Severine and Sindoni, Giuseppe and Stiepen, Arnaud and Trokhimovskiy, Alexander and VanderAuwera, Jean and Viscardy, Sébastien and Whiteway, Jim and Willame, Yannick and Wilquet, Valérie and Wolff, Michael and Wolkenberg, Paulina and Aparicio del Moral, Beatriz and Barzin, Pascal and Beeckman, Bram and BenMoussa, Ali and Berkenbosch, Sophie and Biondi, David and Bonnewijn, Sabrina and Candini, Gian Paolo and Clairquin, Roland and Cubas, Javier and Giordanengo, Boris and Gissot, Samuel and Gomez, Alejandro and Hathi, Brijen and Jeronimo Zafra, Jose and Leese, Mark and Maes, Jeroen and Mazy, Emmanuel and Mazzoli, Alexandra and Meseguer, Jose and Morales, Rafael and Orban, Anne and Pastor-Morales, M. and Perez-grande, Isabel and Queirolo, Claudio and Rodriguez Gomez, Julio and Saggin, Bortolino and Samain, Valérie and Sanz Andres, Angel and Sanz, Rosario and Simar, Juan-Felipe and Thibert, Tanguy},
  title = {Methane on Mars: New insights into the sensitivity of CH4 with the NOMAD/ExoMars spectrometer through its first in-flight calibration},
  journal = {Icarus},
  year = {2019},
  volume = {321},
  pages = {671 – 690},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.icarus.2018.09.021}
}
Lutsch E, Strong K, Jones DBA, Ortega I, Hannigan JW, Dammers E, Shephard MW, Morris E, Murphy K, Evans MJ, Parrington M, Whitburn S, VanDamme M, Clarisse L, Coheur P-F, Clerbaux C, Croft B, Martin RV, Pierce JR and Fisher JA (2019), "Unprecedented Atmospheric Ammonia Concentrations Detected in the High Arctic From the 2017 Canadian Wildfires", Journal of Geophysical Research: Atmospheres. Vol. 124(14), pp. 8178 – 8202.
Abstract: From 17–22 August 2017 simultaneous enhancements of ammonia (NH3), carbon monoxide (CO), hydrogen cyanide (HCN), and ethane (C2H6) were detected from ground-based solar absorption Fourier transform infrared (FTIR) spectroscopic measurements at two high-Arctic sites: Eureka (80.05°N, 86.42°W) Nunavut, Canada, and Thule (76.53°N, 68.74°W), Greenland. These enhancements were attributed to wildfires in British Columbia and the Northwest Territories of Canada using FLEXPART back-trajectories and fire locations from Moderate Resolution Imaging Spectroradiometer (MODIS) and found to be the greatest observed enhancements in more than a decade of measurements at Eureka (2006–2017) and Thule (1999–2017). Observations of gas-phase NH3 from these wildfires illustrate that boreal wildfires may be a considerable episodic source of NH3 in the summertime high Arctic. Comparisons of GEOS-Chem model simulations using the Global Fire Assimilation System (GFASv1.2) biomass burning emissions to FTIR measurements and Infrared Atmospheric Sounding Interferometer (IASI) measurements showed that the transport of wildfire emissions to the Arctic was underestimated in GEOS-Chem. However, GEOS-Chem simulations showed that these wildfires contributed to surface layer NH3 and NH4 + enhancements of 0.01–0.11 ppbv and 0.05–1.07 ppbv, respectively, over the Canadian Archipelago from 15–23 August 2017. ©2019. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Lutsch2019,
  author = {Lutsch, Erik and Strong, Kimberly and Jones, Dylan B. A. and Ortega, Ivan and Hannigan, James W. and Dammers, Enrico and Shephard, Mark W. and Morris, Eleanor and Murphy, Killian and Evans, Mathew J. and Parrington, Mark and Whitburn, Simon and VanDamme, Martin and Clarisse, Lieven and Coheur, Pierre-Francois and Clerbaux, Cathy and Croft, Betty and Martin, Randall V. and Pierce, Jeffrey R. and Fisher, Jenny A.},
  title = {Unprecedented Atmospheric Ammonia Concentrations Detected in the High Arctic From the 2017 Canadian Wildfires},
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2019},
  volume = {124},
  number = {14},
  pages = {8178 – 8202},
  note = {All Open Access, Green Open Access},
  doi = {10.1029/2019JD030419}
}
Maggiolo R, Gibbons A, Cessateur G, Keyser JD, Dhooghe F, Gunell H, Loreau J, Mousis O and Vaeck N (2019), "Effect of the Surface Roughness of Icy Grains on Molecular Oxygen Chemistry in Molecular Clouds", Astrophysical Journal. Vol. 882(2)
Abstract: Molecular cloud and protosolar nebula chemistry involves a strong interaction between the gas phase and the surface of icy grains. The exchanges between the gas phase and the solid phase depend not only on the adsorption and desorption rates but also on the geometry of the surface of the grains. Indeed, for sufficient levels of surface roughness, atoms and molecules have a significant probability to collide with the grain icy mantle several times before being potentially captured. In consequence, their net sticking probability may differ from their sticking probability for a single collision with the grain surface. We estimate the effectiveness of the recapture on uneven surfaces for the various desorption processes at play in astrophysical environments. We show that surface roughness has a significant effect on the desorption rates. We focus in particular on the production of O2 since unexpectedly large amounts of it, probably incorporated in the comet when it formed, have been detected in the coma of comet 67P by the Rosetta probe. Our results suggest that the higher escape probability of hydrogen compared to heavier species on rough surfaces can contribute to enhancing the production of O2 in the icy mantles of grains while keeping its abundance low in the gas phase and may significantly decrease the desorption probability of molecules involved in the O2 chemical network. © 2019. The American Astronomical Society. All rights reserved..
BibTeX:
@article{Maggiolo2019,
  author = {Maggiolo, R. and Gibbons, A. and Cessateur, G. and Keyser, J. De and Dhooghe, F. and Gunell, H. and Loreau, J. and Mousis, O. and Vaeck, N.},
  title = {Effect of the Surface Roughness of Icy Grains on Molecular Oxygen Chemistry in Molecular Clouds},
  journal = {Astrophysical Journal},
  year = {2019},
  volume = {882},
  number = {2},
  note = {All Open Access, Bronze Open Access},
  doi = {10.3847/1538-4357/ab3400}
}
Papoulia A, Ekman J, Gaigalas G, Godefroid M, Gustafsson S, Hartman H, Li W, Radžiute L, Rynku P, Schiffmann S, Wang K and Jönsson P (2019), "Coulomb (Velocity) Gauge Recommended in Multiconfiguration Calculations of Transition Data Involving Rydberg Series", Atoms. Vol. 7(4)
Abstract: Astronomical spectroscopy has recently expanded into the near-infrared (nIR) wavelength region, raising the demands on atomic transition data. The interpretation of the observed spectra largely relies on theoretical results, and progress towards the production of accurate theoretical data must continuously be made. Spectrum calculations that target multiple atomic states at the same time are by nomeans trivial. Further, numerous atomic systems involve Rydberg series,which are associated with additional difficulties. In this work, we demonstrate how the challenges in the computations of Rydberg series can be handled in large-scale multiconfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction (RCI) calculations. By paying special attention to the construction of the radial orbital basis that builds the atomic state functions, transition data that are weakly sensitive to the choice of gauge can be obtained. Additionally, we show that the Babushkin gauge should not always be considered as the preferred gauge, and that, in the computations of transition data involving Rydberg series, the Coulomb gauge could be more appropriate for the analysis of astrophysical spectra. To illustrate the above, results from computations of transitions involving Rydberg series in the astrophysically important C IV and C III ions are presented and analyzed. © 2019 by the authors.
BibTeX:
@article{Papoulia2019,
  author = {Papoulia, Asimina and Ekman, Jörgen and Gaigalas, Gediminas and Godefroid, Michel and Gustafsson, Stefan and Hartman, Henrik and Li, Wenxian and Radžiute, Laima and Rynku, Pavel and Schiffmann, Sacha and Wang, Kai and Jönsson, Per},
  title = {Coulomb (Velocity) Gauge Recommended in Multiconfiguration Calculations of Transition Data Involving Rydberg Series},
  journal = {Atoms},
  year = {2019},
  volume = {7},
  number = {4},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atoms7040106}
}
Pardini F, Queißer M, Naismith A, Watson I, Clarisse L and Burton M (2019), "Initial constraints on triggering mechanisms of the eruption of Fuego volcano (Guatemala) from 3 June 2018 using IASI satellite data", Journal of Volcanology and Geothermal Research. Vol. 376, pp. 54 – 61.
Abstract: On 3 June 2018 Volcán de Fuego (Guatemala) erupted explosively with unusual intensity, producing wide-spread ash dispersal and pyroclastic flows of >11 km length, which destroyed a community on Fuego's flanks, causing hundreds of fatalities. Here, we analyze satellite measurements of the SO 2 plume emitted during the most intense eruptive phase. Key eruption parameters including the injection height and SO 2 flux time-series indicate a degassing intensity at least three orders of magnitude above baseline levels. Our results suggest a steady  2.5 hour climactic paroxysmal phase of the eruption with a mass eruption rate of  1.4kg s −1 based on the combination of plume height estimates and an eruption column model, producing 0.03 ± 0.004 km 3 of tephra. We detect at least 130 kt of emitted SO 2 from satellite images, producing a minimum dissolved magmatic sulfur concentration of 500 ppm. Possible source mechanisms are discussed, which may be useful in assessing the risks posed by future large-magnitude eruptions to the large populations that live on Fuego's flanks. This study shows that even under challenging conditions of a tropical atmosphere during the rainy season, vital eruption parameters to constrain source mechanisms of eruptions can be retrieved from satellite remote sensing data. © 2019 The Authors
BibTeX:
@article{Pardini2019,
  author = {Pardini, F. and Queißer, M. and Naismith, A. and Watson, I.M. and Clarisse, L. and Burton, M.R.},
  title = {Initial constraints on triggering mechanisms of the eruption of Fuego volcano (Guatemala) from 3 June 2018 using IASI satellite data},
  journal = {Journal of Volcanology and Geothermal Research},
  year = {2019},
  volume = {376},
  pages = {54 – 61},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.jvolgeores.2019.03.014}
}
Tzompa-Sosa Z, Henderson B, Keller C, Travis K, Mahieu E, Franco B, Estes M, Helmig D, Fried A, Richter D, Weibring P, Walega J, Blake D, Hannigan J, Ortega I, Conway S, Strong K and Fischer E (2019), " Atmospheric Implications of Large C 2 -C 5 Alkane Emissions From the U.S. Oil and Gas Industry ", Journal of Geophysical Research: Atmospheres. Vol. 124(2), pp. 1148 – 1169.
Abstract: Emissions of C 2 -C 5 alkanes from the U.S. oil and gas sector have changed rapidly over the last decade. We use a nested GEOS-Chem simulation driven by updated 2011NEI emissions with aircraft, surface, and column observations to (1) examine spatial patterns in the emissions and observed atmospheric abundances of C 2 -C 5 alkanes over the United States and (2) estimate the contribution of emissions from the U.S. oil and gas industry to these patterns. The oil and gas sector in the updated 2011NEI contributes over 80% of the total U.S. emissions of ethane (C 2 H 6 ) and propane (C 3 H 8 ), and emissions of these species are largest in the central United States. Observed mixing ratios of C 2 -C 5 alkanes show enhancements over the central United States below 2 km. A nested GEOS-Chem simulation underpredicts observed C 3 H 8 mixing ratios in the boundary layer over several U.S. regions, and the relative underprediction is not consistent, suggesting C 3 H 8 emissions should receive more attention moving forward. Our decision to consider only C 4 -C 5 alkane emissions as a single lumped species produces a geographic distribution similar to observations. Due to the increasing importance of oil and gas emissions in the United States, we recommend continued support of existing long-term measurements of C 2 -C 5 alkanes. We suggest additional monitoring of C 2 -C 5 alkanes downwind of northeastern Colorado, Wyoming, and western North Dakota to capture changes in these regions. The atmospheric chemistry modeling community should also evaluate whether chemical mechanisms that lump larger alkanes are sufficient to understand air quality issues in regions with large emissions of these species. ©2018. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{TzompaSosa2019,
  author = {Tzompa-Sosa, Z.A. and Henderson, B.H. and Keller, C.A. and Travis, K. and Mahieu, E. and Franco, B. and Estes, M. and Helmig, D. and Fried, A. and Richter, D. and Weibring, P. and Walega, J. and Blake, D.R. and Hannigan, J.W. and Ortega, I. and Conway, S. and Strong, K. and Fischer, E.V.},
  title = { Atmospheric Implications of Large C 2 -C 5 Alkane Emissions From the U.S. Oil and Gas Industry },
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2019},
  volume = {124},
  number = {2},
  pages = {1148 – 1169},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1029/2018JD028955}
}
Vandaele AC, Korablev O, Daerden F, Aoki S, Thomas IR, Altieri F, López-Valverde M, Villanueva G, Liuzzi G, Smith MD, Erwin JT, Trompet L, Fedorova AA, Montmessin F, Trokhimovskiy A, Belyaev DA, Ignatiev NI, Luginin M, Olsen KS, Baggio L, Alday J, Bertaux J-L, Betsis D, Bolsée D, Clancy RT, Cloutis E, Depiesse C, Funke B, Garcia-Comas M, Gérard J-C, Giuranna M, Gonzalez-Galindo F, Grigoriev AV, Ivanov YS, Kaminski J, Karatekin O, Lefèvre F, Lewis S, López-Puertas M, Mahieux A, Maslov I, Mason J, Mumma MJ, Neary L, Neefs E, Patrakeev A, Patsaev D, Ristic B, Robert S, Schmidt F, Shakun A, Teanby NA, Viscardy S, Willame Y, Whiteway J, Wilquet V, Wolff MJ, Bellucci G, Patel MR, López-Moreno J-J, Forget F, Wilson CF, Svedhem H, Vago JL, Rodionov D, Alonso-Rodrigo G, Bauduin S, Carrozzo G, Crismani M, Da Pieve F, D’Aversa E, Etiope G, Fussen D, Geminale A, Gkouvelis L, Holmes J, Hubert B, Kasaba Y, Kass D, Kleinböhl A, Lanciano O, Nakagawa H, Novak RE, Oliva F, Piccialli A, Renotte E, Ritter B, Schneider N, Sindoni G, Thiemann E, VanderAuwera J, Wolkenberg P, Yelle R, Anufreychik K, Arnold G, Duxbury N, Fouchet T, Grassi D, Guerlet S, Hartogh P, Khatuntsev I, Kokonkov N, Krasnopolsky V, Kuzmin R, Lacombe G, Lellouch E, Määttänen A, Marcq E, Martin-Torres J, Medvedev A, Millour E, Moshkin B, Patel M, Quantin-Nataf C, Rodin A, Shematovich V, Thomas N, Trokhimovsky A, Vazquez L, Vincendon M, Young R, Zasova L, Zelenyi L and Zorzano MP (2019), "Martian dust storm impact on atmospheric H2O and D/H observed by ExoMars Trace Gas Orbiter", Nature. Vol. 568(7753), pp. 521 – 525.
Abstract: Global dust storms on Mars are rare1,2 but can affect the Martian atmosphere for several months. They can cause changes in atmospheric dynamics and inflation of the atmosphere3, primarily owing to solar heating of the dust3. In turn, changes in atmospheric dynamics can affect the distribution of atmospheric water vapour, with potential implications for the atmospheric photochemistry and climate on Mars4. Recent observations of the water vapour abundance in the Martian atmosphere during dust storm conditions revealed a high-altitude increase in atmospheric water vapour that was more pronounced at high northern latitudes5,6, as well as a decrease in the water column at low latitudes7,8. Here we present concurrent, high-resolution measurements of dust, water and semiheavy water (HDO) at the onset of a global dust storm, obtained by the NOMAD and ACS instruments onboard the ExoMars Trace Gas Orbiter. We report the vertical distribution of the HDO/H2O ratio (D/H) from the planetary boundary layer up to an altitude of 80 kilometres. Our findings suggest that before the onset of the dust storm, HDO abundances were reduced to levels below detectability at altitudes above 40 kilometres. This decrease in HDO coincided with the presence of water-ice clouds. During the storm, an increase in the abundance of H2O and HDO was observed at altitudes between 40 and 80 kilometres. We propose that these increased abundances may be the result of warmer temperatures during the dust storm causing stronger atmospheric circulation and preventing ice cloud formation, which may confine water vapour to lower altitudes through gravitational fall and subsequent sublimation of ice crystals3. The observed changes in H2O and HDO abundance occurred within a few days during the development of the dust storm, suggesting a fast impact of dust storms on the Martian atmosphere. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
BibTeX:
@article{Vandaele2019a,
  author = {Vandaele, Ann Carine and Korablev, Oleg and Daerden, Frank and Aoki, Shohei and Thomas, Ian R. and Altieri, Francesca and López-Valverde, Miguel and Villanueva, Geronimo and Liuzzi, Giuliano and Smith, Michael D. and Erwin, Justin T. and Trompet, Loïc and Fedorova, Anna A. and Montmessin, Franck and Trokhimovskiy, Alexander and Belyaev, Denis A. and Ignatiev, Nikolay I. and Luginin, Mikhail and Olsen, Kevin S. and Baggio, Lucio and Alday, Juan and Bertaux, Jean-Loup and Betsis, Daria and Bolsée, David and Clancy, R. Todd and Cloutis, Edward and Depiesse, Cédric and Funke, Bernd and Garcia-Comas, Maia and Gérard, Jean-Claude and Giuranna, Marco and Gonzalez-Galindo, Francisco and Grigoriev, Alexey V. and Ivanov, Yuriy S. and Kaminski, Jacek and Karatekin, Ozgur and Lefèvre, Franck and Lewis, Stephen and López-Puertas, Manuel and Mahieux, Arnaud and Maslov, Igor and Mason, Jon and Mumma, Michael J. and Neary, Lori and Neefs, Eddy and Patrakeev, Andrey and Patsaev, Dmitry and Ristic, Bojan and Robert, Séverine and Schmidt, Frédéric and Shakun, Alexey and Teanby, Nicholas A. and Viscardy, Sébastien and Willame, Yannick and Whiteway, James and Wilquet, Valérie and Wolff, Michael J. and Bellucci, Giancarlo and Patel, Manish R. and López-Moreno, Jose-Juan and Forget, François and Wilson, Colin F. and Svedhem, Håkan and Vago, Jorge L. and Rodionov, Daniel and Alonso-Rodrigo, Gustavo and Bauduin, Sophie and Carrozzo, Giacomo and Crismani, Matteo and Da Pieve, Fabiana and D’Aversa, Emiliano and Etiope, Giuseppe and Fussen, Didier and Geminale, Anna and Gkouvelis, Leo and Holmes, James and Hubert, Benoît and Kasaba, Yasumasa and Kass, David and Kleinböhl, Armin and Lanciano, Orietta and Nakagawa, Hiromu and Novak, Robert E. and Oliva, Fabrizio and Piccialli, Arianna and Renotte, Etienne and Ritter, Birgit and Schneider, Nick and Sindoni, Giuseppe and Thiemann, Ed and VanderAuwera, Jean and Wolkenberg, Paulina and Yelle, Roger and Anufreychik, Konstantin and Arnold, Gabriele and Duxbury, Natalia and Fouchet, Thierry and Grassi, Davide and Guerlet, Sandrine and Hartogh, Paul and Khatuntsev, Igor and Kokonkov, Nikita and Krasnopolsky, Vladimir and Kuzmin, Ruslan and Lacombe, Gaétan and Lellouch, Emmanuel and Määttänen, Anni and Marcq, Emmanuel and Martin-Torres, Javier and Medvedev, Alexander and Millour, Ehouarn and Moshkin, Boris and Patel, Manish R. and Quantin-Nataf, Cathy and Rodin, Alexander and Shematovich, Valery and Thomas, Nicolas and Trokhimovsky, Alexander and Vazquez, Luis and Vincendon, Matthieu and Young, Roland and Zasova, Ludmila and Zelenyi, Lev and Zorzano, Maria Paz},
  title = {Martian dust storm impact on atmospheric H2O and D/H observed by ExoMars Trace Gas Orbiter},
  journal = {Nature},
  year = {2019},
  volume = {568},
  number = {7753},
  pages = {521 – 525},
  note = {All Open Access, Green Open Access},
  doi = {10.1038/s41586-019-1097-3}
}
Vandaele AC, Korablev O, Daerden F, Aoki S, Thomas IR, Altieri F, López-Valverde M, Villanueva G, Liuzzi G, Smith MD, Erwin JT, Trompet L, Fedorova AA, Montmessin F, Trokhimovskiy A, Belyaev DA, Ignatiev NI, Luginin M, Olsen KS, Baggio L, Alday J, Bertaux J-L, Betsis D, Bolsée D, Clancy RT, Cloutis E, Depiesse C, Funke B, Garcia-Comas M, Gérard J-C, Giuranna M, Gonzalez-Galindo F, Grigoriev AV, Ivanov YS, Kaminski J, Karatekin O, Lefèvre F, Lewis S, López-Puertas M, Mahieux A, Maslov I, Mason J, Mumma MJ, Neary L, Neefs E, Patrakeev A, Patsaev D, Ristic B, Robert S, Schmidt F, Shakun A, Teanby NA, Viscardy S, Willame Y, Whiteway J, Wilquet V, Wolff MJ, Bellucci G, Patel MR, López-Moreno J-J, Forget F, Wilson CF, Young R, Svedhem H, Vago JL, Rodionov D, Alonso-Rodrigo G, Bauduin S, Carrozzo G, Crismani M, Da Pieve F, D’Aversa E, Etiope G, Fussen D, Geminale A, Gkouvelis L, Holmes J, Hubert B, Kasaba Y, Kass D, Kleinböhl A, Lanciano O, Nakagawa H, Novak RE, Oliva F, Piccialli A, Renotte E, Ritter B, Schneider N, Sindoni G, Thiemann E, VanderAuwera J, Wolkenberg P, Yelle R, Anufreychik K, Arnold G, Duxbury N, Fouchet T, Grassi D, Guerlet S, Hartogh P, Khatuntsev I, Kokonkov N, Krasnopolsky V, Kuzmin R, Lacombe G, Lellouch E, Määttänen A, Marcq E, Martin-Torres J, Medvedev A, Millour E, Moshkin B, Quantin-Nataf C, Rodin A, Shematovich V, Thomas N, Trokhimovsky A, Vazquez L, Vincendon M, Zasova L, Zelenyi L and Zorzano MP (2019), "Publisher Correction: Martian dust storm impact on atmospheric H2O and D/H observed by ExoMars Trace Gas Orbiter (Nature, (2019), 568, 7753, (521-525), 10.1038/s41586-019-1097-3)", Nature. Vol. 569(7754), pp. E1.
Abstract: The surname of author Cathy Quantin-Nataf was misspelled ‘Quantin-Nata’ , authors Ehouarn Millour and Roland Young were missing from the ACS Science Team list, and minor changes have been made to the author and affiliation lists; see accompanying Amendment. These errors have been corrected online. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
BibTeX:
@article{Vandaele2019,
  author = {Vandaele, Ann Carine and Korablev, Oleg and Daerden, Frank and Aoki, Shohei and Thomas, Ian R. and Altieri, Francesca and López-Valverde, Miguel and Villanueva, Geronimo and Liuzzi, Giuliano and Smith, Michael D. and Erwin, Justin T. and Trompet, Loïc and Fedorova, Anna A. and Montmessin, Franck and Trokhimovskiy, Alexander and Belyaev, Denis A. and Ignatiev, Nikolay I. and Luginin, Mikhail and Olsen, Kevin S. and Baggio, Lucio and Alday, Juan and Bertaux, Jean-Loup and Betsis, Daria and Bolsée, David and Clancy, R. Todd and Cloutis, Edward and Depiesse, Cédric and Funke, Bernd and Garcia-Comas, Maia and Gérard, Jean-Claude and Giuranna, Marco and Gonzalez-Galindo, Francisco and Grigoriev, Alexey V. and Ivanov, Yuriy S. and Kaminski, Jacek and Karatekin, Ozgur and Lefèvre, Franck and Lewis, Stephen and López-Puertas, Manuel and Mahieux, Arnaud and Maslov, Igor and Mason, Jon and Mumma, Michael J. and Neary, Lori and Neefs, Eddy and Patrakeev, Andrey and Patsaev, Dmitry and Ristic, Bojan and Robert, Séverine and Schmidt, Frédéric and Shakun, Alexey and Teanby, Nicholas A. and Viscardy, Sébastien and Willame, Yannick and Whiteway, James and Wilquet, Valérie and Wolff, Michael J. and Bellucci, Giancarlo and Patel, Manish R. and López-Moreno, Jose-Juan and Forget, François and Wilson, Colin F. and Young, Roland and Svedhem, Håkan and Vago, Jorge L. and Rodionov, Daniel and Alonso-Rodrigo, Gustavo and Bauduin, Sophie and Carrozzo, Giacomo and Crismani, Matteo and Da Pieve, Fabiana and D’Aversa, Emiliano and Etiope, Giuseppe and Fussen, Didier and Geminale, Anna and Gkouvelis, Leo and Holmes, James and Hubert, Benoît and Kasaba, Yasumasa and Kass, David and Kleinböhl, Armin and Lanciano, Orietta and Nakagawa, Hiromu and Novak, Robert E. and Oliva, Fabrizio and Piccialli, Arianna and Renotte, Etienne and Ritter, Birgit and Schneider, Nick and Sindoni, Giuseppe and Thiemann, Ed and VanderAuwera, Jean and Wolkenberg, Paulina and Yelle, Roger and Anufreychik, Konstantin and Arnold, Gabriele and Duxbury, Natalia and Fouchet, Thierry and Grassi, Davide and Guerlet, Sandrine and Hartogh, Paul and Khatuntsev, Igor and Kokonkov, Nikita and Krasnopolsky, Vladimir and Kuzmin, Ruslan and Lacombe, Gaétan and Lellouch, Emmanuel and Määttänen, Anni and Marcq, Emmanuel and Martin-Torres, Javier and Medvedev, Alexander and Millour, Ehouarn and Moshkin, Boris and Quantin-Nataf, Cathy and Rodin, Alexander and Shematovich, Valery and Thomas, Nicolas and Trokhimovsky, Alexander and Vazquez, Luis and Vincendon, Matthieu and Zasova, Ludmila and Zelenyi, Lev and Zorzano, Maria Paz},
  title = {Publisher Correction: Martian dust storm impact on atmospheric H2O and D/H observed by ExoMars Trace Gas Orbiter (Nature, (2019), 568, 7753, (521-525), 10.1038/s41586-019-1097-3)},
  journal = {Nature},
  year = {2019},
  volume = {569},
  number = {7754},
  pages = {E1},
  note = {All Open Access, Bronze Open Access},
  doi = {10.1038/s41586-019-1163-x}
}
Wespes C, Hurtmans D, Chabrillat S, Ronsmans G, Clerbaux C and Coheur P-F (2019), "Is the recovery of stratospheric O3 speeding up in the Southern Hemisphere? An evaluation from the first IASI decadal record (2008-2017)", Atmospheric Chemistry and Physics. Vol. 19(22), pp. 14031 – 14056.
Abstract: In this paper, we present the global fingerprint of recent changes in middle-upper stratosphere (MUSt; 25 hPa) ozone (O3) in comparison with lower stratosphere (LSt; 150-25 hPa) O3 derived from the first 10 years of the IASI/Metop-A satellite measurements (January 2008-December 2017). The IASI instrument provides vertically resolved O3 profiles with very high spatial and temporal (twice daily) samplings, allowing O3 changes to be monitored in these two regions of the stratosphere. By applying multivariate regression models with adapted geophysical proxies on daily mean O3 time series, we discriminate anthropogenic trends from various modes of natural variability, such as the El Niño-Southern Oscillation (ENSO). The representativeness of the O3 response to its natural drivers is first examined. One important finding relies on a pronounced contrast between a positive LSt O3 response to ENSO in the extratropics and a negative one in the tropics, with a delay of 3 months, which supports a stratospheric pathway for the ENSO influence on lower stratospheric and tropospheric O3. In terms of trends, we find an unequivocal O3 recovery from the available period of measurements in winter-spring at middle to high latitudes for the two stratospheric layers sounded by IASI ( 35 N-S in the MUSt and 45 S in the LSt) as well as in the total columns at southern latitudes (45 S) where the increase reaches its maximum. These results confirm the effectiveness of the Montreal Protocol and its amendments and represent the first detection of a significant recovery of O3 concurrently in the lower, in the middle-upper stratosphere and in the total column from one single satellite dataset. A significant decline in O3 at northern mid-latitudes in the LSt is also detected, especially in winter-spring of the Northern Hemisphere. Given counteracting trends in the LSt and MUSt at these latitudes, the decline is not categorical in total O3. When freezing the regression coefficients determined for each natural driver over the whole IASI period but adjusting a trend, we calculate a significant speeding up in the O3 response to the decline of O3-depleting substances (ODSs) in the total column, in the LSt and, to a lesser extent, in the MUSt, at high southern latitudes over the year. Results also show a small significant acceleration of the O3 decline at northern mid-latitudes in the LSt and in the total column over the last few years. That, specifically, needs urgent investigation to identify its exact origin and apprehend its impact on climate change. Additional years of IASI measurements would, however, be required to confirm the O3 change rates observed in the stratospheric layers over the last few years. © Author(s) 2019.
BibTeX:
@article{Wespes2019,
  author = {Wespes, Catherine and Hurtmans, Daniel and Chabrillat, Simon and Ronsmans, Gaetane and Clerbaux, Cathy and Coheur, Pierre-Francois},
  title = {Is the recovery of stratospheric O3 speeding up in the Southern Hemisphere? An evaluation from the first IASI decadal record (2008-2017)},
  journal = {Atmospheric Chemistry and Physics},
  year = {2019},
  volume = {19},
  number = {22},
  pages = {14031 – 14056},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-19-14031-2019}
}
Xie L, Yang X, Wraith C, Babcock C, Bieroń J, Billowes J, Bissell M, Blaum K, Cheal B, Filippin L, Flanagan K, Garcia Ruiz R, Gins W, Gaigalas G, Godefroid M, Gorges C, Grob L, Heylen H, Jönsson P, Kaufmann S, Kowalska M, Krämer J, Malbrunot-Ettenauer S, Neugart R, Neyens G, Nörtershäuser W, Otsuka T, Papuga J, Sánchez R, Tsunoda Y and Yordanov D (2019), "Nuclear charge radii of 62−80Zn and their dependence on cross-shell proton excitations", Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. Vol. 797
Abstract: Nuclear charge radii of 62−80Zn have been determined using collinear laser spectroscopy of bunched ion beams at CERN-ISOLDE. The subtle variations of observed charge radii, both within one isotope and along the full range of neutron numbers, are found to be well described in terms of the proton excitations across the Z=28 shell gap, as predicted by large-scale shell model calculations. It comprehensively explains the changes in isomer-to-ground state mean square charge radii of 69−79Zn, the inversion of the odd-even staggering around N=40 and the odd-even staggering systematics of the Zn charge radii. With two protons above Z=28, the observed charge radii of the Zn isotopic chain show a cumulative effect of different aspects of nuclear structure including single particle structure, shell closure, correlations and deformations near the proposed doubly magic nuclei, 68Ni and 78Ni. © 2019 The Author(s)
BibTeX:
@article{Xie2019,
  author = {Xie, L. and Yang, X.F. and Wraith, C. and Babcock, C. and Bieroń, J. and Billowes, J. and Bissell, M.L. and Blaum, K. and Cheal, B. and Filippin, L. and Flanagan, K.T. and Garcia Ruiz, R.F. and Gins, W. and Gaigalas, G. and Godefroid, M. and Gorges, C. and Grob, L.K. and Heylen, H. and Jönsson, P. and Kaufmann, S. and Kowalska, M. and Krämer, J. and Malbrunot-Ettenauer, S. and Neugart, R. and Neyens, G. and Nörtershäuser, W. and Otsuka, T. and Papuga, J. and Sánchez, R. and Tsunoda, Y. and Yordanov, D.T.},
  title = {Nuclear charge radii of 62−80Zn and their dependence on cross-shell proton excitations},
  journal = {Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics},
  year = {2019},
  volume = {797},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1016/j.physletb.2019.134805}
}
Amyay B, Gardez A, Georges R, Biennier L, VanderAuwera J, Richard C and Boudon V (2018), " Erratum: "New investigation of the ν 3 C-H stretching region of 12 CH 4 through the analysis of high temperature infrared emission spectra" [J. Chem. Phys. 148, 134306 (2018) ", The Journal of chemical physics. Vol. 148(16), pp. 169902.
BibTeX:
@article{Amyay2018a,
  author = {Amyay, Badr and Gardez, Aline and Georges, Robert and Biennier, Ludovic and VanderAuwera, Jean and Richard, Cyril and Boudon, Vincent},
  title = { Erratum: "New investigation of the ν 3 C-H stretching region of 12 CH 4 through the analysis of high temperature infrared emission spectra" [J. Chem. Phys. 148, 134306 (2018) },
  journal = {The Journal of chemical physics},
  year = {2018},
  volume = {148},
  number = {16},
  pages = {169902},
  note = {All Open Access, Bronze Open Access},
  doi = {10.1063/1.5034108}
}
Amyay B, Gardez A, Georges R, Biennier L, VanderAuwera J, Richard C and Boudon V (2018), "New investigation of the ν 3 C-H stretching region of 12CH4 through the analysis of high temperature infrared emission spectra", Journal of Chemical Physics. Vol. 148(13)
Abstract: The ν3 C-H stretching region of methane was reinvestigated in this work using high temperature (620-1715 K) emission spectra recorded in Rennes at Doppler limited resolution. This work follows our recent global analysis of the Dyad system Δn = ±1 (1000-1500 cm-1), with n being the polyad number [B. Amyay et al., J. Chem. Phys. 144, 24312 (2016)]. Thanks to the high temperature, new assignments of vibration-rotation methane line positions have been achieved successfully in the Pentad system and some associated hot bands (Δn = ±2) observed in the spectral region 2600-3300 cm-1. In particular, rotational assignments in the cold band [Pentad-ground state (GS)] and in the first related hot band (Octad-Dyad) were extended up to J = 30 and 27, respectively. In addition, 1525 new transitions belonging to the Tetradecad-Pentad hot band system were assigned for the first time, up to J = 20. The effective global model used to deal with the new assignments was developed to the 6th order for the first three polyads (Monad, Dyad, and Pentad), and to the 5th order for both the Octad and the Tetradecad. 1306 effective parameters were fitted with a dimensionless standard deviation σ = 2.64. The root mean square deviations dRMS obtained are 4.18 × 10-3 cm-1 for the Pentad-GS cold band, 2.48 × 10-3 cm-1 for the Octad-Dyad, and 1.43 × 10-3 cm-1 for the Tetradecad-Pentad hot bands. © 2018 Author(s).
BibTeX:
@article{Amyay2018,
  author = {Amyay, Badr and Gardez, Aline and Georges, Robert and Biennier, Ludovic and VanderAuwera, Jean and Richard, Cyril and Boudon, Vincent},
  title = {New investigation of the ν 3 C-H stretching region of 12CH4 through the analysis of high temperature infrared emission spectra},
  journal = {Journal of Chemical Physics},
  year = {2018},
  volume = {148},
  number = {13},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/1.5023331}
}
Aourir N, Nemouchi M, Godefroid M and Jönsson P (2018), "Theoretical hyperfine structures of F 19 i and O 17 i", Physical Review A. Vol. 97(3)
Abstract: Multiconfiguration Hartree-Fock (MCHF) and multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations are performed for the 2p5Po2, 2p4(3P)3s4P, 2p4(3P)3s2P, and 2p4(3P)3p4So states of F19 i to determine their hyperfine constants. Several computing strategies are considered to investigate electron correlation and relativistic effects. High-order correlation contributions are included in MCHF calculations based on single and double multireference expansions. The largest components of the single reference MCHF wave functions are selected to define the multireference (MR) sets. In this scheme, relativistic corrections are evaluated in the Breit-Pauli approximation. A similar strategy is used for the calculation of MCDHF relativistic wave functions and hyperfine parameters. While correlation and relativistic corrections are found to be rather small for the ground state, we highlight large relativistic effects on the hyperfine constant A3/2 of 2p4(3P)3p4So and, to a lesser extent, on A1/2 of 2p4(3P)3s4P. As expected for such a light system, electron correlation effects dominate over relativity in the calculation of the hyperfine interaction of all other levels considered. We also revisit the hyperfine constants of 2p3(4S)3sSo5 and 2p3(4S)3p5P in O17 using similar strategies. The results are found to be in excellent agreement with experiment. © 2018 American Physical Society.
BibTeX:
@article{Aourir2018,
  author = {Aourir, Nouria and Nemouchi, Messaoud and Godefroid, Michel and Jönsson, Per},
  title = {Theoretical hyperfine structures of F 19 i and O 17 i},
  journal = {Physical Review A},
  year = {2018},
  volume = {97},
  number = {3},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.97.032506}
}
Bauduin S, Irwin P, Lellouch E, Cottini V, Moreno R, Nixon C, Teanby N, Ansty T and Flasar F (2018), "Retrieval of H2O abundance in Titan's stratosphere: A (re)analysis of CIRS/Cassini and PACS/Herschel observations", Icarus. Vol. 311, pp. 288 – 305.
Abstract: Since its first measurement 20 years ago by the Infrared Space Observatory (ISO), the water (H2O) mole fraction in Titan's stratosphere remains uncertain due to large differences between the determinations from available measurements. More particularly, the recent measurements made from the Herschel observatory (PACS and HIFI) estimated the H2O mole fraction to be 0.023 ppb at 12.1 mbar. A mixing ratio of 0.14 ppb at 10.7 mbar was, however, retrieved from nadir spatially-resolved observations of Cassini/CIRS. At the same pressure level (10.7 mbar), this makes a difference of a factor of 5.5 between PACS and CIRS measurements, and this has notably prevented current models from fully constraining the oxygen flux flowing into Titan's atmosphere. In this work, we try to understand the differences between the H2O mole fractions estimated from Herschel/PACS and Cassini/CIRS observations. The strategy for this is to 1) analyse recent disc-averaged observations of CIRS to investigate if the observation geometry could explain the previous observed differences, and 2) (re)analyse the three types of observation with the same retrieval scheme to assess if previous differences in retrieval codes/methodology could be responsible for the previous discrepancies. With this analysis, we show that using the same retrieval method better reconcile the previous measurements of these instruments. However, the addition of the disc-averaged CIRS observations, instead of confirming the consistency between the different datasets, reveals discrepancies between one of the CIRS disc-averaged set of observations and PACS measurements. This raises new questions regarding the possibility of latitudinal variations of H2O, which could be triggered by seasonal changes of the meridional circulation. As it has already been shown for nitriles and hydrocarbons, this circulation could potentially impact the latitudinal distribution of H2O through the subsidence or upwelling of air rich in H2O. The possible influence of spatial/time variations of the OH/H2O input flux in Titan's atmosphere is also discussed. The analysis of more observations will be needed in future work to address the questions arising from this work and to improve the understanding of the sources of H2O in Titan's atmosphere. © 2018 Elsevier Inc.
BibTeX:
@article{Bauduin2018,
  author = {Bauduin, S. and Irwin, P.G.J. and Lellouch, E. and Cottini, V. and Moreno, R. and Nixon, C.A. and Teanby, N.A. and Ansty, T. and Flasar, F.M.},
  title = {Retrieval of H2O abundance in Titan's stratosphere: A (re)analysis of CIRS/Cassini and PACS/Herschel observations},
  journal = {Icarus},
  year = {2018},
  volume = {311},
  pages = {288 – 305},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.icarus.2018.04.003}
}
Bieroń J, Filippin L, Gaigalas G, Godefroid M, Jönsson P and Pyykkö P (2018), "Ab initio calculations of the hyperfine structure of zinc and evaluation of the nuclear quadrupole moment Q(Zn 67)", Physical Review A. Vol. 97(6)
Abstract: The relativistic multiconfiguration Dirac-Hartree-Fock and the nonrelativistic multiconfiguration Hartree-Fock methods have been employed to calculate the magnetic dipole and electric quadrupole hyperfine structure constants of zinc. The calculated electric field gradients for the 4s4pP1o3 and 4s4pP2o3 states, together with experimental values of the electric quadrupole hyperfine structure constants, made it possible to extract a nuclear electric quadrupole moment Q(Zn67)=0.122(10) b. The error bar was evaluated in a quasistatistical approach - the calculations were carried out with 11 different methods, and then the error bar was estimated from the differences between the results obtained with those methods. © 2018 American Physical Society.
BibTeX:
@article{Bieron2018,
  author = {Bieroń, Jacek and Filippin, Livio and Gaigalas, Gediminas and Godefroid, Michel and Jönsson, Per and Pyykkö, Pekka},
  title = {Ab initio calculations of the hyperfine structure of zinc and evaluation of the nuclear quadrupole moment Q(Zn 67)},
  journal = {Physical Review A},
  year = {2018},
  volume = {97},
  number = {6},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.97.062505}
}
Boudon V, Grigoryan T, Philipot F, Richard C, Tchana FK, Manceron L, Rizopoulos A, Auwera JV and Encrenaz T (2018), "Line positions and intensities for the ν3 band of 5 isotopologues of germane for planetary applications", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 205, pp. 174 – 183.
Abstract: The germane molecule, GeH4, is present in the atmospheres of giant planets Jupiter and Saturn. The ongoing NASA mission Juno has renewed interest in its spectroscopy, whose accurate modeling is essential for the retrieval of other tropospheric species. We present here the first complete analysis and modeling of line positions and intensities in the strongly absorbing ν1/ν3 stretching dyad region near 2100 cm−1, for all five germane isotopologues in natural abundance. New infrared spectra were recorded, absolute intensities were extracted through a careful procedure and modeled thanks to the formalism and programs developed in the Dijon group. A database of calculated germane lines, GeCaSDa, has been build and is available online through the Virtual Atomic and Molecular Data Centre (VAMDC) portal and at http://vamdc.icb.cnrs.fr/PHP/gecasda.php. © 2017 Elsevier Ltd
BibTeX:
@article{Boudon2018a,
  author = {Boudon, V. and Grigoryan, T. and Philipot, F. and Richard, C. and Tchana, F. Kwabia and Manceron, L. and Rizopoulos, A. and Auwera, J. Vander and Encrenaz, Th.},
  title = {Line positions and intensities for the ν3 band of 5 isotopologues of germane for planetary applications},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2018},
  volume = {205},
  pages = {174 – 183},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2017.10.017}
}
Boudon V, Sears T and Coheur P-F (2018), "Introduction to the special issue on molecular spectroscopy, atmospheric composition and climate change", Journal of Molecular Spectroscopy. Vol. 348, pp. 1.
BibTeX:
@article{Boudon2018,
  author = {Boudon, Vincent and Sears, Trevor and Coheur, Pierre-François},
  title = {Introduction to the special issue on molecular spectroscopy, atmospheric composition and climate change},
  journal = {Journal of Molecular Spectroscopy},
  year = {2018},
  volume = {348},
  pages = {1},
  doi = {10.1016/j.jms.2018.04.005}
}
Boynard A, Hurtmans D, Garane K, Goutail F, Hadji-Lazaro J, Elissavet Koukouli M, Wespes C, Vigouroux C, Keppens A, Pazmino A, Balis D, Loyola D, Valks P, Sussmann R, Smale D, Coheur P-F and Clerbaux C (2018), "Validation of the IASI FORLI/EUMETSAT ozone products using satellite (GOME-2), ground-based (Brewer-Dobson, SAOZ, FTIR) and ozonesonde measurements", Atmospheric Measurement Techniques. Vol. 11(9), pp. 5125 – 5152.
Abstract:

This paper assesses the quality of IASI (Infrared Atmospheric Sounding Interferometer)/Metop-A (IASI-A) and IASI/Metop-B (IASI-B) ozone (O3) products (total and partial O3 columns) retrieved with the Fast Optimal Retrievals on Layers for IASI Ozone (FORLI-O3; v20151001) software for 9 years (2008-July 2017) through an extensive intercomparison and validation exercise using independent observations (satellite, ground-based and ozonesonde). Compared with the previous version of FORLI-O3 (v20140922), several improvements have been introduced in FORLI-O3 v20151001, including absorbance look-up tables recalculated to cover a larger spectral range, with additional numerical corrections. This leads to a change of ĝ1/4 4&thinsp;% in the total ozone column (TOC) product, which is mainly associated with a decrease in the retrieved O3 concentration in the middle stratosphere (above 30&thinsp;hPa/25&thinsp;km). IASI-A and IASI-B TOCs are consistent, with a global mean difference of less than 0.3&thinsp;% for both daytime and nighttime measurements; IASI-A is slightly higher than IASI-B. A global difference of less than 2.4&thinsp;% is found for the tropospheric (TROPO) O3 column product (IASI-A is lower than IASI-B), which is partly due to a temporary issue related to the IASI-A viewing angle in 2015. Our validation shows that IASI-A and IASI-B TOCs are consistent with GOME-2 (Global Ozone Monitoring Experiment-2), Dobson, Brewer, SAOZ (Système d'Analyse par Observation Zénithale) and FTIR (Fourier transform infrared) TOCs, with global mean differences in the range of 0.1&thinsp;%-2&thinsp;% depending on the instruments compared. The worst agreement with UV-vis retrieved TOC (satellite and ground) is found at the southern high latitudes. The IASI-A and ground-based TOC comparison for the period from 2008 to July 2017 shows the long-Term stability of IASI-A, with insignificant or small negative drifts of 1&thinsp;%-3&thinsp;%&thinsp;decadeĝ'1. The comparison results of IASI-A and IASI-B against smoothed FTIR and ozonesonde partial O3 columns vary with altitude and latitude, with the maximum standard deviation being seen for the 300-150&thinsp;hPa column (20&thinsp;%-40&thinsp;%) due to strong ozone variability and large total retrievals errors. Compared with ozonesonde data, the IASI-A and IASI-B O3 TROPO column (defined as the column between the surface and 300&thinsp;hPa) is positively biased in the high latitudes (4&thinsp;%-5&thinsp;%) and negatively biased in the midlatitudes and tropics (11&thinsp;%-13&thinsp;% and 16&thinsp;%-19&thinsp;%, respectively). The IASI-A-To-ozonesonde TROPO comparison for the period from 2008 to 2016 shows a significant negative drift in the Northern Hemisphere of ĝ'8.6±3.4&thinsp;%&thinsp;decadeĝ'1, which is also found in the IASI-A-To-FTIR TROPO comparison. When considering the period from 2011 to 2016, the drift value for the TROPO column decreases and becomes statistically insignificant. The observed negative drifts of the IASI-A TROPO O3 product (8&thinsp;%-16&thinsp;%&thinsp;decadeĝ'1) over the 2008-2017 period might be taken into consideration when deriving trends from this product and this time period.

. © Author(s) 2018.
BibTeX:
@article{Boynard2018,
  author = {Boynard, Anne and Hurtmans, Daniel and Garane, Katerina and Goutail, Florence and Hadji-Lazaro, Juliette and Elissavet Koukouli, Maria and Wespes, Catherine and Vigouroux, Corinne and Keppens, Arno and Pazmino, Andrea and Balis, Dimitris and Loyola, Diego and Valks, Pieter and Sussmann, Ralf and Smale, Dan and Coheur, Pierre-François and Clerbaux, Cathy},
  title = {Validation of the IASI FORLI/EUMETSAT ozone products using satellite (GOME-2), ground-based (Brewer-Dobson, SAOZ, FTIR) and ozonesonde measurements},
  journal = {Atmospheric Measurement Techniques},
  year = {2018},
  volume = {11},
  number = {9},
  pages = {5125 – 5152},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-11-5125-2018}
}
Brühl C, Schallock J, Klingmüller K, Robert C, Bingen C, Clarisse L, Heckel A, North P and Rieger L (2018), "Stratospheric aerosol radiative forcing simulated by the chemistry climate model EMAC using Aerosol CCI satellite data", Atmospheric Chemistry and Physics. Vol. 18(17), pp. 12845 – 12857.
Abstract: This paper presents decadal simulations of stratospheric and tropospheric aerosol and its radiative effects by the chemistry general circulation model EMAC constrained with satellite observations in the framework of the ESA Aerosol CCI project such as GOMOS (Global Ozone Monitoring by Occultation of Stars) and (A)ATSR ((Advanced) Along Track Scanning Radiometer) on the ENVISAT (European Environmental Satellite), IASI (Infrared Atmospheric Sounding Interferometer) on MetOp (Meteorological Operational Satellite), and, additionally, OSIRIS (Optical Spectrograph and InfraRed Imaging System). In contrast to most other studies, the extinctions and optical depths from the model are compared to the observations at the original wavelengths of the satellite instruments covering the range from the UV (ultraviolet) to terrestrial IR (infrared). This avoids conversion artifacts and provides additional constraints for model aerosol and interpretation of the observations. MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) SO2 limb measurements are used to identify plumes of more than 200 volcanic eruptions. These three-dimensional SO2 plumes are added to the model SO2 at the eruption times. The interannual variability in aerosol extinction in the lower stratosphere, and of stratospheric aerosol radiative forcing at the tropopause, is dominated by the volcanoes. To explain the seasonal cycle of the GOMOS and OSIRIS observations, desert dust simulated by a new approach and transported to the lowermost stratosphere by the Asian summer monsoon and tropical convection turns out to be essential. This also applies to the radiative heating by aerosol in the lowermost stratosphere. The existence of wet dust aerosol in the lowermost stratosphere is indicated by the patterns of the wavelength dependence of extinction in observations and simulations. Additional comparison with (A)ATSR total aerosol optical depth at different wavelengths and IASI dust optical depth demonstrates that the model is able to represent stratospheric as well as tropospheric aerosol consistently. © Author(s) 2018.
BibTeX:
@article{Bruehl2018,
  author = {Brühl, Christoph and Schallock, Jennifer and Klingmüller, Klaus and Robert, Charles and Bingen, Christine and Clarisse, Lieven and Heckel, Andreas and North, Peter and Rieger, Landon},
  title = {Stratospheric aerosol radiative forcing simulated by the chemistry climate model EMAC using Aerosol CCI satellite data},
  journal = {Atmospheric Chemistry and Physics},
  year = {2018},
  volume = {18},
  number = {17},
  pages = {12845 – 12857},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-18-12845-2018}
}
DeRuette N, Dochain A, Launoy T, Nascimento R, Kaminska M, Stockett M, Vaeck N, Schmidt H, Cederquist H and Urbain X (2018), "Mutual Neutralization of O- with O+ and N+ at Subthermal Collision Energies", Physical Review Letters. Vol. 121(8)
Abstract: We have measured total absolute cross sections for the mutual neutralization (MN) of O- with O+ and N+. A fine resolution (of about 50 meV) in the kinetic energy spectra of the product neutral atoms allows unique identification of the atomic states participating in the mutual neutralization process. Cross sections and branching ratios have also been calculated down to 1 meV center-of-mass collision energy for these two systems, with a multichannel Landau-Zener model and an asymptotic method for the ionic-covalent coupling matrix elements. The importance of two-electron processes in one-electron transfer is demonstrated by the dominant contribution of a core-excited configuration of the nitrogen atom in N++O- collisions. This effect is partially accounted for by introducing configuration mixing in the evaluation of coupling matrix elements. © 2018 American Physical Society.
BibTeX:
@article{DeRuette2018,
  author = {DeRuette, N. and Dochain, A. and Launoy, T. and Nascimento, R.F. and Kaminska, M. and Stockett, M.H. and Vaeck, N. and Schmidt, H.T. and Cederquist, H. and Urbain, X.},
  title = {Mutual Neutralization of O- with O+ and N+ at Subthermal Collision Energies},
  journal = {Physical Review Letters},
  year = {2018},
  volume = {121},
  number = {8},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevLett.121.083401}
}
Filippin L, Schiffmann S, Dohet-Eraly J, Baye D and Godefroid M (2018), "Relativistic semiempirical-core-potential calculations in Ca+, Sr+, and Ba+ ions on Lagrange meshes", Physical Review A. Vol. 97(1)
Abstract: Relativistic atomic structure calculations are carried out in alkaline-earth-metal ions using a semiempirical-core-potential approach. The systems are partitioned into frozen-core electrons and an active valence electron. The core orbitals are defined by a Dirac-Hartree-Fock calculation using the grasp2k package. The valence electron is described by a Dirac-like Hamiltonian involving a core-polarization potential to simulate the core-valence electron correlation. The associated equation is solved with the Lagrange-mesh method, which is an approximate variational approach having the form of a mesh calculation because of the use of a Gauss quadrature to calculate matrix elements. Properties involving the low-lying metastable D3/2,5/22 states of Ca+, Sr+, and Ba+ are studied, such as polarizabilities, one- and two-photon decay rates, and lifetimes. Good agreement is found with other theory and observation, which is promising for further applications in alkalilike systems. © 2018 American Physical Society.
BibTeX:
@article{Filippin2018,
  author = {Filippin, Livio and Schiffmann, Sacha and Dohet-Eraly, Jérémy and Baye, Daniel and Godefroid, Michel},
  title = {Relativistic semiempirical-core-potential calculations in Ca+, Sr+, and Ba+ ions on Lagrange meshes},
  journal = {Physical Review A},
  year = {2018},
  volume = {97},
  number = {1},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.97.012506}
}
Franco B, Clarisse L, Stavrakou T, Müller J-F, Van Damme M, Whitburn S, Hadji-Lazaro J, Hurtmans D, Taraborrelli D, Clerbaux C and Coheur P-F (2018), "A General Framework for Global Retrievals of Trace Gases From IASI: Application to Methanol, Formic Acid, and PAN", Journal of Geophysical Research: Atmospheres. Vol. 123(24), pp. 13,963 – 13,984.
Abstract: Retrieving concentrations of minor atmospheric trace gases from satellite observations is challenging due to their weak spectral signature. Here we present a new version of the ANNI (Artificial Neural Network for Infrared Atmospheric Sounding Interferometer, IASI) retrieval framework, which relies on a hyperspectral range index (HRI) for the quantification of the gas spectral signature and on an artificial feedforward neural network to convert the HRI into a gas total column. We detail the different steps of the retrieval method, especially where they differ from previous work, and apply the retrieval to three important volatile organic compounds: methanol (CH 3 OH), formic acid (HCOOH), and peroxyacetyl nitrate (PAN). The comparison of the retrieved columns with those from an optimal estimation inversion retrieval shows an overall excellent agreement: differences occur mainly when the sensitivity to the target gas is low and are consistent with the conceptual differences between the two approaches. We present retrieval examples over selected regions, comparison with previously developed products, and the global seasonal distributions including the first global distributions of PAN on a daily basis. The ANNI retrieval has been carried out on the whole time series of IASI observations (2007–2018), so that currently over 10 years of twice-daily global CH 3 OH, HCOOH, and PAN total column distributions have been produced. This unique data set opens avenues for tackling important questions related to sources, transport, and transformation of volatile organic compounds in the global atmosphere. ©2018. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Franco2018,
  author = {Franco, B. and Clarisse, L. and Stavrakou, T. and Müller, J.-F. and Van Damme, M. and Whitburn, S. and Hadji-Lazaro, J. and Hurtmans, D. and Taraborrelli, D. and Clerbaux, C. and Coheur, P.-F.},
  title = {A General Framework for Global Retrievals of Trace Gases From IASI: Application to Methanol, Formic Acid, and PAN},
  journal = {Journal of Geophysical Research: Atmospheres},
  year = {2018},
  volume = {123},
  number = {24},
  pages = {13,963 – 13,984},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1029/2018JD029633}
}
Gamrath S, Palmeri P, Quinet P, Bouazza S and Godefroid M (2018), "MCDHF calculations of isotope shifts in neutral antimony", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 218, pp. 38 – 45.
Abstract: Ab initio multiconfiguration Dirac–Hartree–Fock (MCDHF) calculations have been carried out in order to determine the isotope shift (IS) electronic parameters of transitions belonging to electric dipole (E1) transition arrays 5s25p3−5s25p26s, 5s25p26s−5s25p26p and 5s25p26s−5s25p27p in neutral antimony, Sb I. In a correlation model limited to single and double excitations from the valence shells, these parameters, combined with the changes in mean-square nuclear charge radius δ⟨r2⟩123,121 compiled by Angeli and Marinova [3] produce isotope shifts values in good agreement with the most recent measurements by high-resolution emission and optogalvanic absorption spectroscopy of Sobolewski et al. [5] but not with the old measurements of Buchholz et al. [4] for 5p3−5p26s. However, our analysis does not allow to reject the latter due to the large uncertainty affecting δ⟨r2⟩123,121, i.e. 0.072 ± 0.048 fm2 [3]. This shows the need of a more accurate determination of this nuclear parameter. Although improving excitation energies, the inclusion of core-valence correlation limited to one hole in the 4d core subshell destroyed the theory-experiment agreement on the IS parameters. © 2018 Elsevier Ltd
BibTeX:
@article{Gamrath2018,
  author = {Gamrath, S. and Palmeri, P. and Quinet, P. and Bouazza, S. and Godefroid, M.},
  title = {MCDHF calculations of isotope shifts in neutral antimony},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2018},
  volume = {218},
  pages = {38 – 45},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2018.07.004}
}
Gaudel A, Cooper O, Ancellet G, Barret B, Boynard A, Burrows J, Clerbaux C, Coheur P-F, Cuesta J, Cuevas E, Doniki S, Dufour G, Ebojie F, Foret G, Garcia O, Granados-Muñoz M, Hannigan J, Hase F, Hassler B, Huang G, Hurtmans D, Jaffe D, Jones N, Kalabokas P, Kerridge B, Kulawik S, Latter B, Leblanc T, Le Flochmoën E, Lin W, Liu J, Liu X, Mahieu E, McClure-Begley A, Neu J, Osman M, Palm M, Petetin H, Petropavlovskikh I, Querel R, Rahpoe N, Rozanov A, Schultz M, Schwab J, Siddans R, Smale D, Steinbacher M, Tanimoto H, Tarasick D, Thouret V, Thompson A, Trickl T, Weatherhead E, Wespes C, Worden H, Vigouroux C, Xu X, Zeng G and Ziemke J (2018), "Tropospheric Ozone Assessment Report: Present-day distribution and trends of tropospheric ozone relevant to climate and global atmospheric chemistry model evaluation", Elementa. Vol. 6
Abstract: The Tropospheric Ozone Assessment Report (TOAR) is an activity of the International Global Atmospheric Chemistry Project. This paper is a component of the report, focusing on the present-day distribution and trends of tropospheric ozone relevant to climate and global atmospheric chemistry model evaluation. Utilizing the TOAR surface ozone database, several figures present the global distribution and trends of daytime average ozone at 2702 non-urban monitoring sites, highlighting the regions and seasons of the world with the greatest ozone levels. Similarly, ozonesonde and commercial aircraft observations reveal ozone's distribution throughout the depth of the free troposphere. Long-term surface observations are limited in their global spatial coverage, but data from remote locations indicate that ozone in the 21st century is greater than during the 1970s and 1980s. While some remote sites and many sites in the heavily polluted regions of East Asia show ozone increases since 2000, many others show decreases and there is no clear global pattern for surface ozone changes since 2000. Two new satellite products provide detailed views of ozone in the lower troposphere across East Asia and Europe, revealing the full spatial extent of the spring and summer ozone enhancements across eastern China that cannot be assessed from limited surface observations. Sufficient data are now available (ozonesondes, satellite, aircraft) across the tropics from South America eastwards to the western Pacific Ocean, to indicate a likely tropospheric column ozone increase since the 1990s. The 2014-2016 mean tropospheric ozone burden (TOB) between 60°N-60°S from five satellite products is 300 Tg ± 4%. While this agreement is excellent, the products differ in their quantification of TOB trends and further work is required to reconcile the differences. Satellites can now estimate ozone's global long-wave radiative effect, but evaluation is difficult due to limited in situ observations where the radiative effect is greatest. © 2018 The Author(s).
BibTeX:
@article{Gaudel2018,
  author = {Gaudel, A. and Cooper, O.R. and Ancellet, G. and Barret, B. and Boynard, A. and Burrows, J.P. and Clerbaux, C. and Coheur, P.-F. and Cuesta, J. and Cuevas, E. and Doniki, S. and Dufour, G. and Ebojie, F. and Foret, G. and Garcia, O. and Granados-Muñoz, M.J. and Hannigan, J.W. and Hase, F. and Hassler, B. and Huang, G. and Hurtmans, D. and Jaffe, D. and Jones, N. and Kalabokas, P. and Kerridge, B. and Kulawik, S. and Latter, B. and Leblanc, T. and Le Flochmoën, E. and Lin, W. and Liu, J. and Liu, X. and Mahieu, E. and McClure-Begley, A. and Neu, J.L. and Osman, M. and Palm, M. and Petetin, H. and Petropavlovskikh, I. and Querel, R. and Rahpoe, N. and Rozanov, A. and Schultz, M.G. and Schwab, J. and Siddans, R. and Smale, D. and Steinbacher, M. and Tanimoto, H. and Tarasick, D.W. and Thouret, V. and Thompson, A.M. and Trickl, T. and Weatherhead, E. and Wespes, C. and Worden, H.M. and Vigouroux, C. and Xu, X. and Zeng, G. and Ziemke, J.},
  title = {Tropospheric Ozone Assessment Report: Present-day distribution and trends of tropospheric ozone relevant to climate and global atmospheric chemistry model evaluation},
  journal = {Elementa},
  year = {2018},
  volume = {6},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1525/elementa.291}
}
Keppens A, Lambert J-C, Granville J, Hubert D, Verhoelst T, Compernolle S, Latter B, Kerridge B, Siddans R, Boynard A, Hadji-Lazaro J, Clerbaux C, Wespes C, Hurtmans DR, Coheur P-F, Van Peet JC, Vander RJ, Garane K, Elissavet Koukouli M, Balis D, Delcloo A, Kivi R, Stübi R, Godin-Beekmann S, vanRoozendael M and Zehner C (2018), "Quality assessment of the Ozone-cci Climate Research Data Package (release 2017) - Part 2: Ground-based validation of nadir ozone profile data products", Atmospheric Measurement Techniques. Vol. 11(6), pp. 3769 – 3800.
Abstract: Atmospheric ozone plays a key role in air quality and the radiation budget of the Earth, both directly and through its chemical influence on other trace gases. Assessments of the atmospheric ozone distribution and associated climate change therefore demand accurate vertically resolved ozone observations with both stratospheric and tropospheric sensitivity, on both global and regional scales, and both in the long term and at shorter timescales. Such observations have been acquired by two series of European nadir-viewing ozone profilers, namely the scattered-light UV-visible spectrometers of the GOME family, launched regularly since 1995 (GOME, SCIAMACHY, OMI, GOME-2A/B, TROPOMI, and the upcoming Sentinel-5 series), and the thermal infrared emission sounders of the IASI type, launched regularly since 2006 (IASI on Metop platforms and the upcoming IASI-NG on Metop-SG). In particular, several Level-2 retrieved, Level-3 monthly gridded, and Level-4 assimilated nadir ozone profile data products have been improved and harmonized in the context of the ozone project of the European Space Agency's Climate Change Initiative (ESA Ozone-cci). To verify their fitness for purpose, these ozone datasets must undergo a comprehensive quality assessment (QA), including (a) detailed identification of their geographical, vertical, and temporal domains of validity; (b) quantification of their potential bias, noise, and drift and their dependences on major influence quantities; and (c) assessment of the mutual consistency of data from different sounders. For this purpose we have applied to the Ozone-cci Climate Research Data Package (CRDP) released in 2017 the versatile QA and validation system Multi-TASTE, which has been developed in the context of several heritage projects (ESA's Multi-TASTE, EUMETSAT's O3M-SAF, and the European Commission's FP6 GEOmon and FP7 QA4ECV). This work, as the second in a series of four Ozone-cci validation papers, reports for the first time on data content studies, information content studies and ground-based validation for both the GOME- and IASI-type climate data records combined. The ground-based reference measurements have been provided by the Network for the Detection of Atmospheric Composition Change (NDACC), NASA's Southern Hemisphere Additional Ozonesonde programme (SHADOZ), and other ozonesonde and lidar stations contributing to the World Meteorological Organisation's Global Atmosphere Watch (WMO GAW). The nadir ozone profile CRDP quality assessment reveals that all nadir ozone profile products under study fulfil the GCOS user requirements in terms of observation frequency and horizontal and vertical resolution. Yet all L2 observations also show sensitivity outliers in the UTLS and are strongly correlated vertically due to substantial averaging kernel fluctuations that extend far beyond the kernel's 15km FWHM. The CRDP typically does not comply with the GCOS user requirements in terms of total uncertainty and decadal drift, except for the UV-visible L4 dataset. The drift values of the L2 GOME and OMI, the L3 IASI, and the L4 assimilated products are found to be overall insignificant, however, and applying appropriate altitude-dependent bias and drift corrections make the data fit for climate and atmospheric composition monitoring and modelling purposes. Dependence of the Ozone-cci data quality on major influence quantities - resulting in data screening suggestions to users - and perspectives for the Copernicus Sentinel missions are additionally discussed. © 2018 Copernicus GmbH. All rights reserved.
BibTeX:
@article{Keppens2018,
  author = {Keppens, Arno and Lambert, Jean-Christopher and Granville, José and Hubert, Daan and Verhoelst, Tijl and Compernolle, Steven and Latter, Barry and Kerridge, Brian and Siddans, Richard and Boynard, Anne and Hadji-Lazaro, Juliette and Clerbaux, Cathy and Wespes, Catherine and Hurtmans, Daniel R. and Coheur, Pierre-François and Van Peet, Jacob C.A. and Vander, Ronald J.A. and Garane, Katerina and Elissavet Koukouli, Maria and Balis, Dimitris and Delcloo, Andy and Kivi, Rigel and Stübi, Réné and Godin-Beekmann, Sophie and vanRoozendael, Michel and Zehner, Claus},
  title = {Quality assessment of the Ozone-cci Climate Research Data Package (release 2017) - Part 2: Ground-based validation of nadir ozone profile data products},
  journal = {Atmospheric Measurement Techniques},
  year = {2018},
  volume = {11},
  number = {6},
  pages = {3769 – 3800},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-11-3769-2018}
}
Lacour J-L, Risi C, Worden J, Clerbaux C and Coheur P-F (2018), "Importance of depth and intensity of convection on the isotopic composition of water vapor as seen from IASI and TES δD observations", Earth and Planetary Science Letters. Vol. 481, pp. 387 – 394.
Abstract: We use tropical observations of the water vapor isotopic composition, derived from IASI and TES spaceborne measurements, to show that the isotopic composition of water vapor in the free troposphere is sensitive to both the depth and the intensity of convection. We find that for any given precipitation intensity, vapor associated with deep convection is isotopically depleted relative to vapor associated with shallow convection. The intensity of precipitation also plays a role as for any given depth of convection, the relative enrichment of water vapor decreases as the intensity of precipitation increases. Shallow convection, via the uplifting of enriched boundary layer air into the free troposphere and the convective detrainment, enriches the free troposphere. In contrast, deep convection is associated with processes that deplete the water vapor in the free troposphere, such as rain re-evaporation. The results of this study allow for a better identification of the parameters controlling the isotopic composition of the free troposphere and indicate that the isotopic composition of water vapor can be used to evaluate the relative contributions of shallow and deep convection in global models. © 2017 Elsevier B.V.
BibTeX:
@article{Lacour2018,
  author = {Lacour, Jean-Lionel and Risi, Camille and Worden, John and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Importance of depth and intensity of convection on the isotopic composition of water vapor as seen from IASI and TES δD observations},
  journal = {Earth and Planetary Science Letters},
  year = {2018},
  volume = {481},
  pages = {387 – 394},
  doi = {10.1016/j.epsl.2017.10.048}
}
Leifer I, Melton C, Tratt DM, Buckland KN, Chang CS, Frash J, Hall JL, Kuze A, Leen B, Clarisse L, Lundquist T, VanDamme M, Vigil S, Whitburn S and Yurganov L (2018), "Validation of mobile in situ measurements of dairy husbandry emissions by fusion of airborne/surface remote sensing with seasonal context from the Chino Dairy Complex", Environmental Pollution. , pp. 2111 – 2134.
Abstract: Mobile in situ concentration and meteorology data were collected for the Chino Dairy Complex in the Los Angeles Basin by AMOG (AutoMObile trace Gas) Surveyor on 25 June 2015 to characterize husbandry emissions in the near and far field in convoy mode with MISTIR (Mobile Infrared Sensor for Tactical Incident Response), a mobile upwards-looking, column remote sensing spectrometer. MISTIR reference flux validated AMOG plume inversions at different information levels including multiple gases, GoogleEarth imagery, and airborne trace gas remote sensing data. Long-term (9-yr.) Infrared Atmospheric Sounding Interferometer satellite data provided spatial and trace gas temporal context. For the Chino dairies, MISTIR-AMOG ammonia (NH3) agreement was within 5% (15.7 versus 14.9 Gg yr−1, respectively) using all information. Methane (CH4) emissions were 30 Gg yr−1 for a 45,200 herd size, indicating that Chino emission factors are greater than previously reported. Single dairy inversions were much less successful. AMOG-MISTIR agreement was 57% due to wind heterogeneity from downwind structures in these near-field measurements and emissions unsteadiness. AMOG CH4, NH3, and CO2 emissions were 91, 209, and 8200 Mg yr−1, implying 2480, 1870, and 1720 head using published emission factors. Plumes fingerprinting identified likely sources including manure storage, cowsheds, and a structure with likely natural gas combustion. NH3 downwind of Chino showed a seasonal variation of a factor of ten, three times larger than literature suggests. Chino husbandry practices and trends in herd size and production were reviewed and unlikely to add seasonality. Higher emission seasonality was proposed as legacy soil emissions, the results of a century of husbandry, supported by airborne remote sensing data showing widespread emissions from neighborhoods that were dairies 15 years prior, and AMOG and MISTIR observations. Seasonal variations provide insights into the implications of global climate change and must be considered when comparing surveys from different seasons. Where sufficient information from multiple gases and number of likely sources, high emissions accuracy can be achieved for in situ data plume inversion. © 2018
BibTeX:
@article{Leifer2018,
  author = {Leifer, Ira and Melton, Christopher and Tratt, David M. and Buckland, Kerry N. and Chang, Clement S. and Frash, Jason and Hall, Jeffrey L. and Kuze, Akihiko and Leen, Brian and Clarisse, Lieven and Lundquist, Tryg and VanDamme, Martin and Vigil, Sam and Whitburn, Simon and Yurganov, Leonid},
  title = {Validation of mobile in situ measurements of dairy husbandry emissions by fusion of airborne/surface remote sensing with seasonal context from the Chino Dairy Complex},
  journal = {Environmental Pollution},
  year = {2018},
  pages = {2111 – 2134},
  doi = {10.1016/j.envpol.2018.03.078}
}
Loreau J, Ryabchenko S, Burgos JMM and Vaeck N (2018), "Charge transfer in low-energy collisions of H with He+ and H+ with He in excited states", Journal of Physics B: Atomic, Molecular and Optical Physics. Vol. 51(8)
Abstract: The charge transfer process in collisions of excited (n = 2, 3) hydrogen atoms with He+ and in collisions of excited helium atoms with H+ is studied theoretically. A combination of a fully quantum-mechanical method and a semi-classical approach is employed to calculate the charge-exchange cross sections at collision energies from 0.1 eV u-1 up to 1 keV u-1. These methods are based on accurate ab initio potential energy curves and non-adiabatic couplings for the molecular ion HeH+. Charge transfer can occur either in singlet or in triplet states, and the differences between the singlet and triplet spin manifolds are discussed. The dependence of the cross section on the quantum numbers n and l of the initial state is demonstrated. The isotope effect on the charge transfer cross sections, arising at low collision energy when H is substituted by D or T, is investigated. Rate coefficients are calculated for all isotopes up to 106 K. Finally, the impact of the present calculations on models of laboratory plasmas is discussed. © 2018 IOP Publishing Ltd.
BibTeX:
@article{Loreau2018,
  author = {Loreau, J. and Ryabchenko, S. and Burgos, J M Munoz and Vaeck, N.},
  title = {Charge transfer in low-energy collisions of H with He+ and H+ with He in excited states},
  journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  year = {2018},
  volume = {51},
  number = {8},
  note = {All Open Access, Green Open Access},
  doi = {10.1088/1361-6455/aab425}
}
Luo J, Pan LL, Honomichl SB, Bergman JW, Randel WJ, Francis G, Clerbaux C, George M, Liu X and Tian W (2018), "Space-time variability in UTLS chemical distribution in the Asian summer monsoon viewed by limb and nadir satellite sensors", Atmospheric Chemistry and Physics. Vol. 18(16), pp. 12511 – 12530.
Abstract: The Asian summer monsoon (ASM) creates a hemispheric-scale signature in trace-gas distributions in the upper troposphere and lower stratosphere (UTLS). Data from satellite retrievals are the best source of information for characterizing these large-scale signatures. Measurements from the Microwave Limb Sounder (MLS), a limb-viewing satellite sensor, have been the most widely used retrieval products for these types of studies. This work explores the information for the ASM influence on UTLS chemical distribution from two nadir-viewing sensors, the Infrared Atmospheric Sounding Interferometer (IASI) and the Ozone Monitoring Instrument (OMI), together with the MLS. Day-to-day changes in carbon monoxide (CO) and ozone (O3) tracer distributions in response to dynamical variability are examined to assess how well the data from different sensors provide useful information for studying the impact of sub-seasonal-scale dynamics on chemical fields. Our results, using June-August 2008 data, show that although the MLS provides relatively sparse horizontal sampling on daily timescales, interpolated daily CO distributions show a high degree of dynamical consistency with the synoptic-scale structure of and variability in the anticyclone. Our analysis also shows that the IASI CO retrieval has sufficient sensitivity to produce upper tropospheric (UT) CO with variabilities independent from the lower to middle tropospheric CO. The consistency of IASI CO field with the synoptic-scale anticyclone dynamical variability demonstrates that the IASI UT CO product is a physically meaningful dataset. Furthermore, IASI CO vertical cross sections combined with the daily maps provide the first observational evidence for a model analyses-based hypothesis on the preferred ASM vertical transport location and the subsequent horizontal redistribution via east-west eddy shedding. Similarly, the OMI O3 profile product is shown to be capable of distinguishing the tropospheric-dominated air mass in the anticyclone from the stratospheric-dominated background on a daily timescale, providing consistent and complementary information to the MLS. These results not only highlight the complementary information between nadir and limb sensors but also demonstrate the value of process-based retrieval evaluation for characterizing satellite data information content. © 2018 Copernicus GmbH. All rights reserved.
BibTeX:
@article{Luo2018,
  author = {Luo, Jiali and Pan, Laura L. and Honomichl, Shawn B. and Bergman, John W. and Randel, William J. and Francis, Gene and Clerbaux, Cathy and George, Maya and Liu, Xiong and Tian, Wenshou},
  title = {Space-time variability in UTLS chemical distribution in the Asian summer monsoon viewed by limb and nadir satellite sensors},
  journal = {Atmospheric Chemistry and Physics},
  year = {2018},
  volume = {18},
  number = {16},
  pages = {12511 – 12530},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-18-12511-2018}
}
Lurton T, Jégou F, Berthet G, Renard J-B, Clarisse L, Schmidt A, Brogniez C and Roberts TJ (2018), "Model simulations of the chemical and aerosol microphysical evolution of the Sarychev Peak 2009 eruption cloud compared to in situ and satellite observations", Atmospheric Chemistry and Physics. Vol. 18(5), pp. 3223 – 3247.
Abstract: Volcanic eruptions impact climate through the injection of sulfur dioxide (SO2), which is oxidized to form sulfuric acid aerosol particles that can enhance the stratospheric aerosol optical depth (SAOD). Besides large-magnitude eruptions, moderate-magnitude eruptions such as Kasatochi in 2008 and Sarychev Peak in 2009 can have a significant impact on stratospheric aerosol and hence climate. However, uncertainties remain in quantifying the atmospheric and climatic impacts of the 2009 Sarychev Peak eruption due to limitations in previous model representations of volcanic aerosol microphysics and particle size, whilst biases have been identified in satellite estimates of post-eruption SAOD. In addition, the 2009 Sarychev Peak eruption co-injected hydrogen chloride (HCl) alongside SO2, whose potential stratospheric chemistry impacts have not been investigated to date. We present a study of the stratospheric SO2-particle-HCl processing and impacts following Sarychev Peak eruption, using the Community Earth System Model version 1.0 (CESM1) Whole Atmosphere Community Climate Model (WACCM)-Community Aerosol and Radiation Model for Atmospheres (CARMA) sectional aerosol microphysics model (with no a priori assumption on particle size). The Sarychev Peak 2009 eruption injected 0.9ĝ€Tg of SO2 into the upper troposphere and lower stratosphere (UTLS), enhancing the aerosol load in the Northern Hemisphere. The post-eruption evolution of the volcanic SO2 in space and time are well reproduced by the model when compared to Infrared Atmospheric Sounding Interferometer (IASI) satellite data. Co-injection of 27ĝ€Ggĝ€†HCl causes a lengthening of the SO2 lifetime and a slight delay in the formation of aerosols, and acts to enhance the destruction of stratospheric ozone and mono-nitrogen oxides (NOx) compared to the simulation with volcanic SO2 only. We therefore highlight the need to account for volcanic halogen chemistry when simulating the impact of eruptions such as Sarychev on stratospheric chemistry. The model-simulated evolution of effective radius (reff) reflects new particle formation followed by particle growth that enhances reff to reach up to 0.2ĝ€μm on zonal average. Comparisons of the model-simulated particle number and size distributions to balloon-borne in situ stratospheric observations over Kiruna, Sweden, in August and September 2009, and over Laramie, USA, in June and November 2009 show good agreement and quantitatively confirm the post-eruption particle enhancement. We show that the model-simulated SAOD is consistent with that derived from the Optical Spectrograph and InfraRed Imager System (OSIRIS) when both the saturation bias of OSIRIS and the fact that extinction profiles may terminate well above the tropopause are taken into account. Previous modelling studies (involving assumptions on particle size) that reported agreement with (biased) post-eruption estimates of SAOD derived from OSIRIS likely underestimated the climate impact of the 2009 Sarychev Peak eruption. © Author(s) 2018.
BibTeX:
@article{Lurton2018,
  author = {Lurton, Thibaut and Jégou, Fabrice and Berthet, Gwenaël and Renard, Jean-Baptiste and Clarisse, Lieven and Schmidt, Anja and Brogniez, Colette and Roberts, Tjarda J},
  title = {Model simulations of the chemical and aerosol microphysical evolution of the Sarychev Peak 2009 eruption cloud compared to in situ and satellite observations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2018},
  volume = {18},
  number = {5},
  pages = {3223 – 3247},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-18-3223-2018}
}
Lyoussi A, Doizi D, Reymond La Ruinaz S, Haykal I, Manceron L, Perrin A, Boudon V, VanderAuwera J, Tchana FK and Faye M (2018), "Analytical measurements of fission products during a severe nuclear accident", EPJ Web of Conferences. Vol. 170
Abstract: The Fukushima accident emphasized the fact that ways to monitor in real time the evolution of a nuclear reactor during a severe accident remain to be developed. No fission products were monitored during twelve days; only dose rates were measured, which is not sufficient to carry out an online diagnosis of the event. The first measurements were announced with little reliability for low volatile fission products. In order to improve the safety of nuclear plants and minimize the industrial, ecological and health consequences of a severe accident, it is necessary to develop new reliable measurement systems, operating at the earliest and closest to the emission source of fission products. Through the French program ANR « Projet d'Investissement d'Avenir , the aim of the DECA-PF project (diagnosis of core degradation from fission products measurements) is to monitor in real time the release of the major fission products (krypton, xenon, gaseous forms of iodine and ruthenium) outside the nuclear reactor containment. These products are released at different times during a nuclear accident and at different states of the nuclear core degradation. Thus, monitoring these fission products gives information on the situation inside the containment and helps to apply the Severe Accident Management procedures. Analytical techniques have been proposed and evaluated. The results are discussed here. © The Authors, published by EDP Sciences, 2018.
BibTeX:
@conference{Lyoussi2018,
  author = {Lyoussi, A. and Doizi, D. and Reymond La Ruinaz, S. and Haykal, I. and Manceron, L. and Perrin, A. and Boudon, V. and VanderAuwera, J. and Tchana, F. Kwabia and Faye, M.},
  title = {Analytical measurements of fission products during a severe nuclear accident},
  journal = {EPJ Web of Conferences},
  year = {2018},
  volume = {170},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1051/epjconf/201817008005}
}
Müller J-F, Stavrakou T, Bauwens M, George M, Hurtmans D, Coheur P-F, Clerbaux C and Sweeney C (2018), "Top-Down CO Emissions Based On IASI Observations and Hemispheric Constraints on OH Levels", Geophysical Research Letters. Vol. 45(3), pp. 1621 – 1629.
Abstract: Assessments of carbon monoxide emissions through inverse modeling are dependent on the modeled abundance of the hydroxyl radical (OH) which controls both the primary sink of CO and its photochemical source through hydrocarbon oxidation. However, most chemistry transport models (CTMs) fall short of reproducing constraints on hemispherically averaged OH levels derived from methylchloroform (MCF) observations. Here we construct five different OH fields compatible with MCF-based analyses, and we prescribe those fields in a global CTM to infer CO fluxes based on Infrared Atmospheric Sounding Interferometer (IASI) CO columns. Each OH field leads to a different set of optimized emissions. Comparisons with independent data (surface, ground-based remotely sensed, aircraft) indicate that the inversion adopting the lowest average OH level in the Northern Hemisphere (7.8 × 105 molec cm−3, ∼18% lower than the best estimate based on MCF measurements) provides the best overall agreement with all tested observation data sets. ©2018. The Authors.
BibTeX:
@article{Mueller2018,
  author = {Müller, J.-F. and Stavrakou, T. and Bauwens, M. and George, M. and Hurtmans, D. and Coheur, P.-F. and Clerbaux, C. and Sweeney, C.},
  title = {Top-Down CO Emissions Based On IASI Observations and Hemispheric Constraints on OH Levels},
  journal = {Geophysical Research Letters},
  year = {2018},
  volume = {45},
  number = {3},
  pages = {1621 – 1629},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1002/2017GL076697}
}
Nechita-Banda N, Krol M, Van Der Werf GR, Kaiser JW, Pandey S, Huijnen V, Clerbaux C, Coheur P, Deeter MN and Röckmann T (2018), "Monitoring emissions from the 2015 Indonesian fires using CO satellite data", Philosophical Transactions of the Royal Society B: Biological Sciences. Vol. 373(1760)
Abstract: Southeast Asia, in particular Indonesia, has periodically struggled with intense fire events. These events convert substantial amounts of carbon stored as peat to atmospheric carbon dioxide (CO2) and significantly affect atmospheric composition on a regional to global scale. During the recent 2015 El Niño event, peat fires led to strong enhancements of carbon monoxide (CO), an air pollutant and well-known tracer for biomass burning. These enhancements were clearly observed from space by the Infrared Atmospheric Sounding Interferometer (IASI) and the Measurements of Pollution in the Troposphere (MOPITT) instruments. We use these satellite observations to estimate CO fire emissions within an inverse modelling framework. We find that the derived CO emissions for each sub-region of Indonesia and Papua are substantially different from emission inventories, highlighting uncertainties in bottom-up estimates. CO fire emissions based on either MOPITT or IASI have a similar spatial pattern and evolution in time, and a 10% uncertainty based on a set of sensitivity tests we performed. Thus, CO satellite data have a high potential to complement existing operational fire emission estimates based on satellite observations of fire counts, fire radiative power and burned area, in better constraining fire occurrence and the associated conversion of peat carbon to atmospheric CO2. A total carbon release to the atmosphere of 0.35–0.60 Pg C can be estimated based on our results. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’. © 2018 The Authors.
BibTeX:
@article{NechitaBanda2018,
  author = {Nechita-Banda, Narcisa and Krol, Maarten and Van Der Werf, Guido R. and Kaiser, Johannes W. and Pandey, Sudhanshu and Huijnen, Vincent and Clerbaux, Cathy and Coheur, Pierre and Deeter, Merritt N. and Röckmann, Thomas},
  title = {Monitoring emissions from the 2015 Indonesian fires using CO satellite data},
  journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
  year = {2018},
  volume = {373},
  number = {1760},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1098/rstb.2017.0307}
}
Nightingale J, Boersma KF, Muller J-P, Compernolle S, Lambert J-C, Blessing S, Giering R, Gobron N, Smedt ID, Coheur P, George M, Schulz J and Wood A (2018), "Quality assurance framework development based on six new ECV data products to enhance user confidence for climate applications", Remote Sensing. Vol. 10(8)
Abstract: Data from Earth observation (EO) satellites are increasingly used to monitor the environment, understand variability and change, inform evaluations of climate model forecasts, and manage natural resources. Policymakers are progressively relying on the information derived from these datasets to make decisions on mitigating and adapting to climate change. These decisions should be evidence based, which requires confidence in derived products, as well as the reference measurements used to calibrate, validate, or inform product development. In support of the European Union's Earth Observation Programmes Copernicus Climate Change Service (C3S), the Quality Assurance for Essential Climate Variables (QA4ECV) project fulfilled a gap in the delivery of climate quality satellite-derived datasets, by prototyping a generic system for the implementation and evaluation of quality assurance (QA) measures for satellite-derived ECV climate data record products. The project demonstrated the QA system on six new long-term, climate quality ECV data records for surface albedo, leaf area index (LAI), fraction of absorbed photosynthetically active radiation (FAPAR), nitrogen dioxide (NO2), formaldehyde (HCHO), and carbon monoxide (CO). The provision of standardised QA information provides data users with evidence-based confidence in the products and enables judgement on the fitness-for-purpose of various ECV data products and their specific applications. © 2018 by the authors.
BibTeX:
@article{Nightingale2018,
  author = {Nightingale, Joanne and Boersma, Klaas Folkert and Muller, Jan-Peter and Compernolle, Steven and Lambert, Jean-Christopher and Blessing, Simon and Giering, Ralf and Gobron, Nadine and Smedt, Isabelle De and Coheur, Pierre and George, Maya and Schulz, Jörg and Wood, Alexander},
  title = {Quality assurance framework development based on six new ECV data products to enhance user confidence for climate applications},
  journal = {Remote Sensing},
  year = {2018},
  volume = {10},
  number = {8},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/rs10081254}
}
Ronsmans G, Wespes C, Hurtmans D, Clerbaux C and Coheur P-F (2018), "Spatio-temporal variations of nitric acid total columns from 9 years of IASI measurements-A driver study", Atmospheric Chemistry and Physics. Vol. 18(7), pp. 4403 – 4423.
Abstract: This study aims to understand the spatial and temporal variability of HNO3 total columns in terms of explanatory variables. To achieve this, multiple linear regressions are used to fit satellite-derived time series of HNO3 daily averaged total columns. First, an analysis of the IASI 9-year time series (2008-2016) is conducted based on various equivalent latitude bands. The strong and systematic denitrification of the southern polar stratosphere is observed very clearly. It is also possible to distinguish, within the polar vortex, three regions which are differently affected by the denitrification. Three exceptional denitrification episodes in 2011, 2014 and 2016 are also observed in the Northern Hemisphere, due to unusually low arctic temperatures. The time series are then fitted by multivariate regressions to identify what variables are responsible for HNO3 variability in global distributions and time series, and to quantify their respective influence. Out of an ensemble of proxies (annual cycle, solar flux, quasi-biennial oscillation, multivariate ENSO index, Arctic and Antarctic oscillations and volume of polar stratospheric clouds), only the those defined as significant (p value<0.05) by a selection algorithm are retained for each equivalent latitude band. Overall, the regression gives a good representation of HNO3 variability, with especially good results at high latitudes (60-80% of the observed variability explained by the model). The regressions show the dominance of annual variability in all latitudinal bands, which is related to specific chemistry and dynamics depending on the latitudes. We find that the polar stratospheric clouds (PSCs) also have a major influence in the polar regions, and that their inclusion in the model improves the correlation coefficients and the residuals. However, there is still a relatively large portion of HNO3 variability that remains unexplained by the model, especially in the intertropical regions, where factors not included in the regression model (such as vegetation fires or lightning) may be at play. © 2018 Author(s).
BibTeX:
@article{Ronsmans2018,
  author = {Ronsmans, Gaétane and Wespes, Catherine and Hurtmans, Daniel and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Spatio-temporal variations of nitric acid total columns from 9 years of IASI measurements-A driver study},
  journal = {Atmospheric Chemistry and Physics},
  year = {2018},
  volume = {18},
  number = {7},
  pages = {4403 – 4423},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-18-4403-2018}
}
Santos L, Herman M, Desouter-Lecomte M and Vaeck N (2018), "Rovibrational laser control targeting a dark state in acetylene. Simulation in the Ns = 1, Nr = 5 polyad", Molecular Physics. Vol. 116(17), pp. 2213 – 2225.
Abstract: Optimal control theory in the Liouville space is used to perform rovibrational control by means of a laser pulse in a polyad of acetylene in order to populate a dark vibrational state. The initial mixed state is a truncated Boltzmann distribution of rotational levels from J=27 to J=31 of the ground vibrational state. The target state is a rotational equidistribution of levels ranging from J=28 to J=32 of the first excited vibrational dark state including quanta of energy in each bending modes, with positive vibrational angular momenta. The simulation is performed by using a manifold of eigenstates of a full-dimensional Hamiltonian calibrated by high precision spectroscopy known as the global acetylene Hamiltonian [B. Amyay et al., J. Chem. Phys. 131, 114301 (2009)]. The control is successful as an Uhlmann's fidelity of 0.98 is reached. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.
BibTeX:
@article{Santos2018,
  author = {Santos, L. and Herman, M. and Desouter-Lecomte, M. and Vaeck, N.},
  title = {Rovibrational laser control targeting a dark state in acetylene. Simulation in the Ns = 1, Nr = 5 polyad},
  journal = {Molecular Physics},
  year = {2018},
  volume = {116},
  number = {17},
  pages = {2213 – 2225},
  note = {All Open Access, Green Open Access},
  doi = {10.1080/00268976.2018.1469797}
}
Schultz MG, Stadtler S, Schröder S, Taraborrelli D, Franco B, Krefting J, Henrot A, Ferrachat S, Lohmann U, Neubauer D, Siegenthaler-Le Drian C, Wahl S, Kokkola H, Kühn T, Rast S, Schmidt H, Stier P, Kinnison D, Tyndall GS, Orlando JJ and Wespes C (2018), "The chemistry-climate model ECHAM6.3-HAM2.3-MOZ1.0", Geoscientific Model Development. Vol. 11(5), pp. 1695 – 1723.
Abstract: The chemistry-climate model ECHAM-HAMMOZ contains a detailed representation of tropospheric and stratospheric reactive chemistry and state-of-the-art parameterizations of aerosols using either a modal scheme (M7) or a bin scheme (SALSA). This article describes and evaluates the model version ECHAM6.3-HAM2.3-MOZ1.0 with a focus on the tropospheric gas-phase chemistry. A 10-year model simulation was performed to test the stability of the model and provide data for its evaluation. The comparison to observations concentrates on the year 2008 and includes total column observations of ozone and CO from IASI and OMI, Aura MLS observations of temperature, HNO3, ClO, and O3 for the evaluation of polar stratospheric processes, an ozonesonde climatology, surface ozone observations from the TOAR database, and surface CO data from the Global Atmosphere Watch network. Global budgets of ozone, OH, NOx, aerosols, clouds, and radiation are analyzed and compared to the literature. ECHAM-HAMMOZ performs well in many aspects. However, in the base simulation, lightning NOx emissions are very low, and the impact of the heterogeneous reaction of HNO3 on dust and sea salt aerosol is too strong. Sensitivity simulations with increased lightning NOx or modified heterogeneous chemistry deteriorate the comparison with observations and yield excessively large ozone budget terms and too much OH. We hypothesize that this is an impact of potential issues with tropical convection in the ECHAM model. © 2018 Author(s).
BibTeX:
@article{Schultz2018,
  author = {Schultz, Martin G. and Stadtler, Scarlet and Schröder, Sabine and Taraborrelli, Domenico and Franco, Bruno and Krefting, Jonathan and Henrot, Alexandra and Ferrachat, Sylvaine and Lohmann, Ulrike and Neubauer, David and Siegenthaler-Le Drian, Colombe and Wahl, Sebastian and Kokkola, Harri and Kühn, Thomas and Rast, Sebastian and Schmidt, Hauke and Stier, Philip and Kinnison, Doug and Tyndall, Geoffrey S. and Orlando, John J. and Wespes, Catherine},
  title = {The chemistry-climate model ECHAM6.3-HAM2.3-MOZ1.0},
  journal = {Geoscientific Model Development},
  year = {2018},
  volume = {11},
  number = {5},
  pages = {1695 – 1723},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/gmd-11-1695-2018}
}
Sun K, Zhu L, Cady-Pereira K, Chan Miller C, Chance K, Clarisse L, Coheur P-F, González Abad G, Huang G, Liu X, VanDamme M, Yang K and Zondlo M (2018), "A physics-based approach to oversample multi-satellite, multispecies observations to a common grid", Atmospheric Measurement Techniques. Vol. 11(12), pp. 6679 – 6701.
Abstract: Satellite remote sensing of the Earth's atmospheric composition usually samples irregularly in space and time, and many applications require spatially and temporally averaging the satellite observations (level 2) to a regular grid (level 3). When averaging level 2 data over a long period to a target level 3 grid that is significantly finer than the sizes of level 2 pixels, this process is referred to as. An agile, physics-based oversampling approach is developed to represent each satellite observation as a sensitivity distribution on the ground, instead of a point or a polygon as assumed in previous methods. This sensitivity distribution can be determined by the spatial response function of each satellite sensor. A generalized 2-D super Gaussian function is proposed to characterize the spatial response functions of both imaging grating spectrometers (e.g., OMI, OMPS, and TROPOMI) and scanning Fourier transform spectrometers (e.g., GOSAT, IASI, and CrIS). Synthetic OMI and IASI observations were generated to compare the errors due to simplifying satellite fields of view (FOVs) as polygons (tessellation error) and the errors due to discretizing the smooth spatial response function on a finite grid (discretization error). The balance between these two error sources depends on the target grid size, the ground size of the FOV, and the smoothness of spatial response functions. Explicit consideration of the spatial response function is favorable for fine-grid oversampling and smoother spatial response. For OMI, it is beneficial to oversample using the spatial response functions for grids finer than ∼ 16 km. The generalized 2-D super Gaussian function also enables smoothing of the level 3 results by decreasing the shape-determining exponents, which is useful for a high noise level or sparse satellite datasets. This physical oversampling approach is especially advantageous during smaller temporal windows and shows substantially improved visualization of trace gas distribution and local gradients when applied to OMI NO2 products and IASI NH3 products. There is no appreciable difference in the computational time when using the physical oversampling versus other oversampling methods. © 2018 Author(s).
BibTeX:
@article{Sun2018,
  author = {Sun, Kang and Zhu, Lei and Cady-Pereira, Karen and Chan Miller, Christopher and Chance, Kelly and Clarisse, Lieven and Coheur, Pierre-François and González Abad, Gonzalo and Huang, Guanyu and Liu, Xiong and VanDamme, Martin and Yang, Kai and Zondlo, Mark},
  title = {A physics-based approach to oversample multi-satellite, multispecies observations to a common grid},
  journal = {Atmospheric Measurement Techniques},
  year = {2018},
  volume = {11},
  number = {12},
  pages = {6679 – 6701},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-11-6679-2018}
}
Vandaele AC, Lopez-Moreno J-J, Patel M, Bellucci G, Daerden F, Ristic B, Robert S, Thomas IR, Wilquet V, Allen M, Alonso-Rodrigo G, Altieri F, Aoki S, Bolsée D, Clancy T, Cloutis E, Depiesse C, Drummond R, Fedorova A, Formisano V, Funke B, González-Galindo F, Geminale A, Gérard J-C, Giuranna M, Hetey L, Ignatiev N, Kaminski J, Karatekin O, Kasaba Y, Leese M, Lefèvre F, Lewis SR, López-Puertas M, López-Valverde M, Mahieux A, Mason J, McConnell J, Mumma M, Neary L, Neefs E, Renotte E, Rodriguez-Gomez J, Sindoni G, Smith M, Stiepen A, Trokhimovsky A, VanderAuwera J, Villanueva G, Viscardy S, Whiteway J, Willame Y, Wolff M, Patel M, D’aversa E, Fussen D, Garcia-Comas M, Hewson W, McConnel J, Novak R, Oliva F, Piccialli A, Aparicio Del Moral B, Barzin P, Benmoussa A, Berkenbosch S, Biondi D, Bonnewijn S, Candini GP, Clairquin R, Cubas J, De-Lanoye S, Giordanengo B, Gissot S, Gomez A, Maes J, Mazy E, Mazzoli A, Meseguer J, Morales R, Orban A, Pastor-Morales MDC, Perez-Grande I, Queirolo C, Saggin B, Samain V, Sanz Andres A, Sanz R, Simar J-F, Thibert T and Zafra JJ (2018), "NOMAD, an Integrated Suite of Three Spectrometers for the ExoMars Trace Gas Mission: Technical Description, Science Objectives and Expected Performance", Space Science Reviews. Vol. 214(5)
Abstract: The NOMAD (“Nadir and Occultation for MArs Discovery”) spectrometer suite on board the ExoMars Trace Gas Orbiter (TGO) has been designed to investigate the composition of Mars’ atmosphere, with a particular focus on trace gases, clouds and dust. The detection sensitivity for trace gases is considerably improved compared to previous Mars missions, compliant with the science objectives of the TGO mission. This will allow for a major leap in our knowledge and understanding of the Martian atmospheric composition and the related physical and chemical processes. The instrument is a combination of three spectrometers, covering a spectral range from the UV to the mid-IR, and can perform solar occultation, nadir and limb observations. In this paper, we present the science objectives of the instrument and explain the technical principles of the three spectrometers. We also discuss the expected performance of the instrument in terms of spatial and temporal coverage and detection sensitivity. © 2018, The Author(s).
BibTeX:
@article{Vandaele2018,
  author = {Vandaele, Ann Carine and Lopez-Moreno, J.-J. and Patel, M.R. and Bellucci, Giancarlo and Daerden, Frank and Ristic, Bojan and Robert, Séverine and Thomas, Ian R. and Wilquet, Valerie and Allen, Mark and Alonso-Rodrigo, Gustavo and Altieri, Francesca and Aoki, Shohei and Bolsée, David and Clancy, Todd and Cloutis, Edward and Depiesse, Cédric and Drummond, Rachel and Fedorova, Anna and Formisano, Vittorio and Funke, Bernd and González-Galindo, F. and Geminale, Anna and Gérard, Jean-Claude and Giuranna, Marco and Hetey, Laszlo and Ignatiev, Nicolai and Kaminski, Jacek and Karatekin, Ozgur and Kasaba, Yasumasa and Leese, Mark and Lefèvre, Franck and Lewis, Stephen R. and López-Puertas, Manuel and López-Valverde, Miguel and Mahieux, Arnaud and Mason, Jon and McConnell, J. and Mumma, Mike and Neary, Lori and Neefs, Eddy and Renotte, Etienne and Rodriguez-Gomez, Julio and Sindoni, Giuseppe and Smith, Mike and Stiepen, Arnaud and Trokhimovsky, Alexander and VanderAuwera, Jean and Villanueva, Geronimo and Viscardy, Sébastien and Whiteway, Jim and Willame, Yannick and Wolff, Mike and Patel, Manish and D’aversa, Emiliano and Fussen, Didier and Garcia-Comas, Maya and Hewson, Will and McConnel, Jack and Novak, Robert and Oliva, Fabrizio and Piccialli, Arianna and Aparicio Del Moral, Beatriz and Barzin, Pascal and Benmoussa, Ali and Berkenbosch, Sophie and Biondi, David and Bonnewijn, Sabrina and Candini, Gian Paolo and Clairquin, Roland and Cubas, Javier and De-Lanoye, Sofie and Giordanengo, Boris and Gissot, Samuel and Gomez, Alejandro and Maes, Jeroen and Mazy, Emmanuel and Mazzoli, Alexandra and Meseguer, Jose and Morales, Rafael and Orban, Anne and Pastor-Morales, Maria Del Carmen and Perez-Grande, Isabel and Queirolo, Claudio and Saggin, Bortolino and Samain, Valérie and Sanz Andres, Angel and Sanz, Rosario and Simar, Juan-Felipe and Thibert, Tanguy and Zafra, Jose Jeronimo},
  title = {NOMAD, an Integrated Suite of Three Spectrometers for the ExoMars Trace Gas Mission: Technical Description, Science Objectives and Expected Performance},
  journal = {Space Science Reviews},
  year = {2018},
  volume = {214},
  number = {5},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1007/s11214-018-0517-2}
}
VanDamme M, Clarisse L, Whitburn S, Hadji-Lazaro J, Hurtmans D, Clerbaux C and Coheur P-F (2018), "Industrial and agricultural ammonia point sources exposed", Nature. Vol. 564(7734), pp. 99 – 103.
Abstract: Through its important role in the formation of particulate matter, atmospheric ammonia affects air quality and has implications for human health and life expectancy1,2. Excess ammonia in the environment also contributes to the acidification and eutrophication of ecosystems3–5 and to climate change6. Anthropogenic emissions dominate natural ones and mostly originate from agricultural, domestic and industrial activities7. However, the total ammonia budget and the attribution of emissions to specific sources remain highly uncertain across different spatial scales7–9. Here we identify, categorize and quantify the world’s ammonia emission hotspots using a high-resolution map of atmospheric ammonia obtained from almost a decade of daily IASI satellite observations. We report 248 hotspots with diameters smaller than 50 kilometres, which we associate with either a single point source or a cluster of agricultural and industrial point sources—with the exception of one hotspot, which can be traced back to a natural source. The state-of-the-art EDGAR emission inventory10 mostly agrees with satellite-derived emission fluxes within a factor of three for larger regions. However, it does not adequately represent the majority of point sources that we identified and underestimates the emissions of two-thirds of them by at least one order of magnitude. Industrial emitters in particular are often found to be displaced or missing. Our results suggest that it is necessary to completely revisit the emission inventories of anthropogenic ammonia sources and to account for the rapid evolution of such sources over time. This will lead to better health and environmental impact assessments of atmospheric ammonia and the implementation of suitable nitrogen management strategies. © 2018, Springer Nature Limited.
BibTeX:
@article{VanDamme2018,
  author = {VanDamme, Martin and Clarisse, Lieven and Whitburn, Simon and Hadji-Lazaro, Juliette and Hurtmans, Daniel and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Industrial and agricultural ammonia point sources exposed},
  journal = {Nature},
  year = {2018},
  volume = {564},
  number = {7734},
  pages = {99 – 103},
  note = {All Open Access, Green Open Access},
  doi = {10.1038/s41586-018-0747-1}
}
VanderAuwera J, Reymond-Laruinaz S, Boudon V, Doizi D and Manceron L (2018), "Line intensity measurements and analysis in the ν3 band of ruthenium tetroxide", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 204, pp. 103 – 111.
Abstract: Ruthenium tetroxide (RuO4) is a heavy tetrahedral molecule characterized by an unusual volatility near ambient temperature. Because of its chemical toxicity and the radiological impact of its 103Ru and 106Ru isotopologues, the possible remote sensing of this compound in the atmosphere has renewed interest in its spectroscopic properties. The present contribution is the first investigation dealing with high-resolution line-by-line intensity measurements for the strong fundamental band observed near 10 μm, associated with the excitation of the infrared active stretching mode ν3. It relies on new, high resolution FTIR spectra recorded at room temperature, using a specially constructed cell and an isotopically pure sample of 102Ru16O4. Relying on an effective Hamiltonian and associated effective dipole moment [S Reymond–Laruinaz et al, J Mol Spectrosc 2015;315:46–54], the measured line intensities were assigned and dipole moment parameters determined. A HITRAN-formatted frequency and intensity line list was generated. © 2017 Elsevier Ltd
BibTeX:
@article{VanderAuwera2018a,
  author = {VanderAuwera, J. and Reymond-Laruinaz, S. and Boudon, V. and Doizi, D. and Manceron, L.},
  title = {Line intensity measurements and analysis in the ν3 band of ruthenium tetroxide},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2018},
  volume = {204},
  pages = {103 – 111},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jqsrt.2017.09.016}
}
VanderAuwera J and Vanfleteren T (2018), "Line positions and intensities in the 7400–8600 cm−1 region of the ammonia spectrum* ", Molecular Physics. Vol. 116(23-24), pp. 3621 – 3630.
Abstract: The positions and intensities of 1936 lines observed in the range 7400–8600 cm−1 of two absorption spectra of ammonia recorded at high resolution using Fourier transform spectroscopy are reported. The accuracy of these line positions is estimated to range from 0.001 to 0.002 cm−1 from the lower to the upper limits of the spectral range considered, while the accuracy of the line intensities is estimated to be around 10% or better. Also reported are less-accurately measured positions and intensities of 1985 lines retrieved from these two spectra or from only one of them. These results are compared with the data measured recently in a spectrum recorded in 1980 at the Kitt Peak National Solar Observatory [Barton et al., J. Mol. Spectrosc. 325, 7 (2016)] and provided in HITRAN 2016, as well as line positions and intensities measured in this work in the same Kitt Peak spectrum. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.
BibTeX:
@article{VanderAuwera2018,
  author = {VanderAuwera, J. and Vanfleteren, T.},
  title = {Line positions and intensities in the 7400–8600 cm−1 region of the ammonia spectrum* },
  journal = {Molecular Physics},
  year = {2018},
  volume = {116},
  number = {23-24},
  pages = {3621 – 3630},
  note = {All Open Access, Green Open Access},
  doi = {10.1080/00268976.2018.1467054}
}
Wang K, Song C, Jönsson P, Zanna GD, Schiffmann S, Godefroid M, Gaigalas G, Zhao X, Si R, Chen C and Yan J (2018), "Benchmarking Atomic Data from Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: S-like Ions from Crix to Cuxiv", Astrophysical Journal, Supplement Series. Vol. 239(2)
Abstract: We present a consistent set of calculated energies and E1, M1, E2, M2 radiative transition data for the main n = 3 levels from the 3s 23p 4, 3p 6, 3p6, 3s3p43d, 3s23p23d2, 3s3p5, 3s23p33d, and 3s3p33d2 configurations for S-like ions from Cr ix to Cu xiv. The fully relativistic multiconfiguration Dirac-Hartree-Fock method implemented in the GRASP2K code is used to perform the present calculations. The excitation energies of the lowest 47 levels from the , , and configurations, producing the strongest lines, are found to be in good agreement, reaching spectroscopic accuracy, with the latest experimental values for Fe xi evaluated by Del Zanna. Our energies can reliably be used to identify in astrophysical and laboratory spectra the levels in other S-like ions, which are mostly unknown. On the contrary, significant discrepancies with the 3s3p 43d levels were found, emphasizing the need for more detailed experimental studies. A few new tentative identifications are suggested. The benchmarks we present indicate that our consistent set of radiative data is accurate and can be used for spectral line modeling. © 2018. The American Astronomical Society. All rights reserved..
BibTeX:
@article{Wang2018a,
  author = {Wang, K. and Song, C.X. and Jönsson, P. and Zanna, G. Del and Schiffmann, S. and Godefroid, M. and Gaigalas, G. and Zhao, X.H. and Si, R. and Chen, C.Y. and Yan, J.},
  title = {Benchmarking Atomic Data from Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: S-like Ions from Crix to Cuxiv},
  journal = {Astrophysical Journal, Supplement Series},
  year = {2018},
  volume = {239},
  number = {2},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.3847/1538-4365/aaedba}
}
Wang K, Song CX, Jönsson P, Ekman J, Godefroid M, Zhang CY, Si R, Zhao XH, Chen CY and Yan J (2018), "Large-scale Multiconfiguration Dirac-Hartree-Fock and Relativistic Configuration Interaction Calculations of Transition Data for B-like S xii", Astrophysical Journal. Vol. 864(2)
Abstract: Excitation energies and lifetimes for the 213 lowest states of the n ≤ 5 configurations in B-like S xii are calculated using highly correlated wave functions, optimized with the fully relativistic multiconfiguration Dirac-Hartree-Fock method. Multipole transition rates and associated radiative data (line strengths and oscillator strengths) for transitions connecting these levels are also reported. The theoretical excitation energies are systematically compared with the NIST Atomic Spectra Database in which misidentifications are pointed out. After eliminating the latter, a mean energy difference with the standard deviation between computed and observed energies of 12 ±341 cm-1 is obtained for the n ≥ 3 high-lying states. This level of accuracy confirms that elaborate ab initio calculations can assist in the identification of new emission lines in the solar and other astrophysical spectra. The present work provides atomic data of high accuracy for an ion of astrophysical interest, B-like S xii, for which experimental data are scarce. © 2018. The American Astronomical Society. All rights reserved.
BibTeX:
@article{Wang2018,
  author = {Wang, Kai and Song, Chang Xian and Jönsson, Per and Ekman, Jörgen and Godefroid, Michel and Zhang, Chun Yu and Si, Ran and Zhao, Xiao Hui and Chen, Chong Yang and Yan, Jun},
  title = {Large-scale Multiconfiguration Dirac-Hartree-Fock and Relativistic Configuration Interaction Calculations of Transition Data for B-like S xii},
  journal = {Astrophysical Journal},
  year = {2018},
  volume = {864},
  number = {2},
  note = {All Open Access, Bronze Open Access},
  doi = {10.3847/1538-4357/aad5dc}
}
Wespes C, Hurtmans D, Clerbaux C, Boynard A and Coheur P-F (2018), "Decrease in tropospheric O3 levels in the Northern Hemisphere observed by IASI", Atmospheric Chemistry and Physics. Vol. 18(9), pp. 6867 – 6885.
Abstract: In this study, we describe the recent changes in the tropospheric ozone (O3) columns measured by the Infrared Atmospheric Sounding Interferometer (IASI), onboard the Metop satellite, during the first 9 years of operation (January 2008 to May 2017). Using appropriate multivariate regression methods, we differentiate significant linear trends from other sources of O3 variations captured by IASI. The geographical patterns of the adjusted O3 trends are provided and discussed on the global scale. Given the large contribution of the natural variability in comparison with that of the trend (25-85% vs. 15-50%, respectively) to the total O3 variations, we estimate that additional years of IASI measurements are generally required to detect the estimated O3 trends with high precision. Globally, additional 6 months to 6 years of measurements, depending on the regions and the seasons, are needed to detect a trend of |5|DUdecadeg-1. An exception is interestingly found during summer at mid-and high latitudes of the Northern Hemisphere (NH; ∼ 40 to ∼75°N), where the large absolute fitted trend values (∼ |0.5|DUyrg-1 on average) combined with the small model residuals (∼ 10%) allow for detection of a band-like pattern of significant negative trends. Despite no consensus in terms of tropospheric O3 trends having been reached from the available independent datasets (UV or IR satellites, O3 sondes, aircrafts, ground-based measurements, etc.) for the reasons that are discussed in the text, this finding is consistent with the reported decrease in O3 precursor emissions in recent years, especially in Europe and USA. The influence of continental pollution on that latitudinal band is further investigated and supported by the analysis of the O3-CO relationship (in terms of correlation coefficient, regression slope and covariance) that we found to be the strongest at northern midlatitudes in summer. © 2018 Author(s).
BibTeX:
@article{Wespes2018,
  author = {Wespes, Catherine and Hurtmans, Daniel and Clerbaux, Cathy and Boynard, Anne and Coheur, Pierre-François},
  title = {Decrease in tropospheric O3 levels in the Northern Hemisphere observed by IASI},
  journal = {Atmospheric Chemistry and Physics},
  year = {2018},
  volume = {18},
  number = {9},
  pages = {6867 – 6885},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-18-6867-2018}
}
Alkadrou A, Bourgeois M-T, Rotger M, Boudon V and VanderAuwera J (2017), "Corrigendum to “Global frequency and intensity analysis of the ν10/ν7/ν4/ν12 band system of 12C2H4 at 10 μm using the D2 h top data system” (Journal of Quantitative Spectroscopy and Radiative Transfer (2017) 190 (88) (S0022407315303162) (10.1016/j.jqsrt.2016.05.024))", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 190, pp. 88.
Abstract: This corrigendum provides a new version of one of the 3 supplementary data files associated with the article A. Alkadrou et al., J. Quant. Spectrosc. Radiat. Transf. 182 (2016) 158–171, namely the HITRAN-formatted linelist generated as described in section 5 of the article. Indeed, the Ka and Kc labels of the upper levels of a number of transitions belonging to the ν10, ν7 and ν4 bands listed in this supplementary data file were found to be incorrect. The linelist provided with this corrigendum corrects these erroneous assignments, and provides Ka and Kc labels for all the upper levels. © 2017 Elsevier Ltd
BibTeX:
@article{Alkadrou2017,
  author = {Alkadrou, A. and Bourgeois, M.-T. and Rotger, M. and Boudon, V. and VanderAuwera, J.},
  title = {Corrigendum to “Global frequency and intensity analysis of the ν10/ν7/ν4/ν12 band system of 12C2H4 at 10 μm using the D2 h top data system” (Journal of Quantitative Spectroscopy and Radiative Transfer (2017) 190 (88) (S0022407315303162) (10.1016/j.jqsrt.2016.05.024))},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2017},
  volume = {190},
  pages = {88},
  doi = {10.1016/j.jqsrt.2017.01.007}
}
Bauduin S, Clarisse L, Theunissen M, George M, Hurtmans D, Clerbaux C and Coheur P-F (2017), "IASI's sensitivity to near-surface carbon monoxide (CO): Theoretical analyses and retrievals on test cases", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 189, pp. 428 – 440.
Abstract: Separating concentrations of carbon monoxide (CO) in the boundary layer from the rest of the atmosphere with nadir satellite measurements is of particular importance to differentiate emission from transport. Although thermal infrared (TIR) satellite sounders are considered to have limited sensitivity to the composition of the near-surface atmosphere, previous studies show that they can provide information on CO close to the ground in case of high thermal contrast. In this work we investigate the capability of IASI (Infrared Atmospheric Sounding Interferometer) to retrieve near-surface CO concentrations, and we quantitatively assess the influence of thermal contrast on such retrievals. We present a 3-part analysis, which relies on both theoretical forward simulations and retrievals on real data, performed for a large range of negative and positive thermal contrast situations. First, we derive theoretically the IASI detection threshold of CO enhancement in the boundary layer, and we assess its dependence on thermal contrast. Then, using the optimal estimation formalism, we quantify the role of thermal contrast on the error budget and information content of near-surface CO retrievals. We demonstrate that, contrary to what is usually accepted, large negative thermal contrast values (ground cooler than air) lead to a better decorrelation between CO concentrations in the low and the high troposphere than large positive thermal contrast (ground warmer than the air). In the last part of the paper we use Mexico City and Barrow as test cases to contrast our theoretical predictions with real retrievals, and to assess the accuracy of IASI surface CO retrievals through comparisons to ground-based in-situ measurements. © 2017 Elsevier Ltd
BibTeX:
@article{Bauduin2017,
  author = {Bauduin, Sophie and Clarisse, Lieven and Theunissen, Michael and George, Maya and Hurtmans, Daniel and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {IASI's sensitivity to near-surface carbon monoxide (CO): Theoretical analyses and retrievals on test cases},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2017},
  volume = {189},
  pages = {428 – 440},
  note = {All Open Access, Bronze Open Access},
  doi = {10.1016/j.jqsrt.2016.12.022}
}
Bègue N, Vignelles D, Berthet G, Portafaix T, Payen G, Jégou F, Benchérif H, Jumelet J, Lurton T, Renard J-B, Clarisse L, Duverger V, Posny F, Metzger J-M and Godin-Beekmann S (2017), "Long-range transport of stratospheric aerosols in the Southern Hemisphere following the 2015 Calbuco eruption", Atmospheric Chemistry and Physics. Vol. 17(24), pp. 15019 – 15036.
Abstract: After 43 years of inactivity, the Calbuco volcano, which is located in the southern part of Chile, erupted on 22 April 2015. The space-time evolutions (distribution and transport) of its aerosol plume are investigated by combining satellite (CALIOP, IASI, OMPS), in situ aerosol counting (LOAC OPC) and lidar observations, and the MIMOSA advection model. The Calbuco aerosol plume reached the Indian Ocean 1 week after the eruption. Over the Reunion Island site (21 S, 55.5 E), the aerosol signal was unambiguously enhanced in comparison with "background" conditions, with a volcanic aerosol layer extending from 18 to 21 km during the May-July period. All the data reveal an increase by a factor of 2 in the SAOD (stratospheric aerosol optical depth) with respect to values observed before the eruption. The aerosol mass e-folding time is approximately 90 days, which is rather close to the value (80 days) reported for the Sarychev eruption. Microphysical measurements obtained before, during, and after the eruption reflecting the impact of the Calbuco eruption on the lower stratospheric aerosol content have been analyzed over the Reunion Island site. During the passage of the plume, the volcanic aerosol was characterized by an effective radius of 0.160.02 μm with a unimodal size distribution for particles above 0.2 μm in diameter. Particle concentrations for sizes larger than 1 μm are too low to be properly detected by the LOAC OPC. The aerosol number concentration was 20 times higher that observed before and 1 year after the eruption. According to OMPS and lidar observations, a tendency toward conditions before the eruption was observed by April 2016. The volcanic aerosol plume is advected eastward in the Southern Hemisphere and its latitudinal extent is clearly bounded by the subtropical barrier and the polar vortex. The transient behavior of the aerosol layers observed above Reunion Island between May and July 2015 reflects an inhomogeneous spatio-temporal distribution of the plume, which is controlled by the localization of these dynamical barriers. © Author(s) 2017.
BibTeX:
@article{Begue2017,
  author = {Bègue, Nelson and Vignelles, Damien and Berthet, Gwenaël and Portafaix, Thierry and Payen, Guillaume and Jégou, Fabrice and Benchérif, Hassan and Jumelet, Julien and Lurton, Thibaut and Renard, Jean-Baptiste and Clarisse, Lieven and Duverger, Vincent and Posny, Françoise and Metzger, Jean-Marc and Godin-Beekmann, Sophie},
  title = {Long-range transport of stratospheric aerosols in the Southern Hemisphere following the 2015 Calbuco eruption},
  journal = {Atmospheric Chemistry and Physics},
  year = {2017},
  volume = {17},
  number = {24},
  pages = {15019 – 15036},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-17-15019-2017}
}
Doppelbauer MJ, Schullian O, Loreau J, Vaeck N, Van Der Avoird A, Rennick CJ, Softley TP and Heazlewood BR (2017), "Using a direct simulation Monte Carlo approach to model collisions in a buffer gas cell", Journal of Chemical Physics. Vol. 146(4)
Abstract: A direct simulation Monte Carlo (DSMC) method is applied to model collisions between He buffer gas atoms and ammonia molecules within a buffer gas cell. State-to-state cross sections, calculated as a function of the collision energy, enable the inelastic collisions between He and NH3 to be considered explicitly. The inclusion of rotational-state-changing collisions affects the translational temperature of the beam, indicating that elastic and inelastic processes should not be considered in isolation. The properties of the cold molecular beam exiting the cell are examined as a function of the cell parameters and operating conditions; the rotational and translational energy distributions are in accord with experimental measurements. The DSMC calculations show that thermalisation occurs well within the typical 10-20 mm length of many buffer gas cells, suggesting that shorter cells could be employed in many instances - yielding a higher flux of cold molecules. © 2017 Author(s).
BibTeX:
@article{Doppelbauer2017,
  author = {Doppelbauer, Maximilian J. and Schullian, Otto and Loreau, Jerome and Vaeck, Nathalie and Van Der Avoird, Ad and Rennick, Christopher J. and Softley, Timothy P. and Heazlewood, Brianna R.},
  title = {Using a direct simulation Monte Carlo approach to model collisions in a buffer gas cell},
  journal = {Journal of Chemical Physics},
  year = {2017},
  volume = {146},
  number = {4},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1063/1.4974253}
}
Duflot V, Baray J-L, Payen G, Marquestaut N, Posny F, Metzger J-M, Langerock B, Vigouroux C, Hadji-Lazaro J, Portafaix T, De Mazière M, Coheur P-F, Clerbaux C and Cammas J-P (2017), "Tropospheric ozone profiles by DIAL at Maïdo Observatory (Reunion Island): System description, instrumental performance and result comparison with ozone external data set", Atmospheric Measurement Techniques. Vol. 10(9), pp. 3359 – 3373.
Abstract: In order to recognize the importance of ozone (O3) in the troposphere and lower stratosphere in the tropics, a DIAL (differential absorption lidar) tropospheric O3 lidar system (LIO3TUR) was developed and installed at the Université de la Réunion campus site (close to the sea) on Reunion Island (southern tropics) in 1998. From 1998 to 2010, it acquired 427 O3 profiles from the low to the upper troposphere and has been central to several studies. In 2012, the system was moved up to the new Maïdo Observatory facility (2160-l. - metres above mean sea level) where it started operation in February 2013. The current system (LIO3T) configuration generates a 266 beam obtained with the fourth harmonic of a Nd:YAG laser sent into a Raman cell filled up with deuterium (using helium as buffer gas), generating the 289 and 316 beams to enable the use of the DIAL method for O3 profile measurements. The optimal range for the actual system is 6-19ga.m.s.l., depending on the instrumental and atmospheric conditions. For a 1gh integration time, vertical resolution varies from 0.7gkm at 6ga.m.s.l. to 1.3gkm at 19ga.m.s.l., and mean uncertainty within the 6-19gkm range is between 6 and 13g%. Comparisons with eight electrochemical concentration cell (ECC) sondes simultaneously launched from the Maïdo Observatory show good agreement between data sets with a 6.8g% mean absolute relative difference (D) between 6 and 17ga.m.s.l. (LIO3T lower than ECC). Comparisons with 37 ECC sondes launched from the nearby Gillot site during the daytime in a ±24gh window around lidar shooting result in a 9.4g% D between 6 and 19ga.m.s.l. (LIO3T lower than ECC). Comparisons with 11 ground-based Network for Detection of Atmospheric Composition Change (NDACC) Fourier transform infrared (FTIR) spectrometer measurements acquired during the daytime in a ±24gh window around lidar shooting show good agreement between data sets with a D of 11.8g% for the 8.5-16gkm partial column (LIO3T higher than FTIR), and comparisons with 39 simultaneous Infrared Atmospheric Sounding Interferometer (IASI) observations over Reunion Island show good agreement between data sets with a D of 11.3g% for the 6-16gkm partial column (LIO3T higher than IASI). ECC, LIO3TUR and LIO3T O3 monthly climatologies all exhibit the same range of values and patterns. In particular, the Southern Hemisphere biomass burning seasonal enhancement and the ozonopause altitude decrease in late austral winter-spring, as well as the sign of deep convection bringing boundary layer O3-poor air masses up to the middle-upper troposphere in late austral summer, are clearly visible in all data sets. © Author(s) 2017.
BibTeX:
@article{Duflot2017,
  author = {Duflot, Valentin and Baray, Jean-Luc and Payen, Guillaume and Marquestaut, Nicolas and Posny, Francoise and Metzger, Jean-Marc and Langerock, Bavo and Vigouroux, Corinne and Hadji-Lazaro, Juliette and Portafaix, Thierry and De Mazière, Martine and Coheur, Pierre-Francois and Clerbaux, Cathy and Cammas, Jean-Pierre},
  title = {Tropospheric ozone profiles by DIAL at Maïdo Observatory (Reunion Island): System description, instrumental performance and result comparison with ozone external data set},
  journal = {Atmospheric Measurement Techniques},
  year = {2017},
  volume = {10},
  number = {9},
  pages = {3359 – 3373},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-10-3359-2017}
}
Filippin L, Bieroń J, Gaigalas G, Godefroid M and Jönsson P (2017), "Multiconfiguration calculations of electronic isotope-shift factors in Zn i", Physical Review A. Vol. 96(4)
Abstract: The present work reports results from systematic multiconfiguration Dirac-Hartree-Fock calculations of electronic isotope-shift factors for a set of transitions between low-lying states in neutral zinc. These electronic quantities, together with observed isotope shifts between different pairs of isotopes, provide the changes in mean-square charge radii of the atomic nuclei. Within this computational approach, different models for electron correlation are explored in a systematic way to determine a reliable computational strategy and to estimate theoretical error bars of the isotope-shift factors. © 2017 American Physical Society.
BibTeX:
@article{Filippin2017,
  author = {Filippin, Livio and Bieroń, Jacek and Gaigalas, Gediminas and Godefroid, Michel and Jönsson, Per},
  title = {Multiconfiguration calculations of electronic isotope-shift factors in Zn i},
  journal = {Physical Review A},
  year = {2017},
  volume = {96},
  number = {4},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.96.042502}
}
Fusina L, DiLonardo G, Canè E, Predoi-Cross A, Rozario H and Herman M (2017), "The high resolution spectrum of 15NH3 in the far-infrared: Rotation-inversion transitions in the ground, v2=1, 2 and v4=1 states", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 203, pp. 417 – 424.
Abstract: The high resolution spectrum of 15NH3 has been recorded at unapodized resolution of 0.00096 cm−1 in the region 60–600 cm−1 using the Bruker IFS 125 Fourier transform spectrometer located at the far-infrared beam-line, Canadian Light Source. We report on the observation and analysis of the rotation-inversion spectrum in the ground, v2=1, 2 and v4=1 states. All the rotation-inversion transitions in the ground state together with the pure inversion transitions present in the literature were fitted simultaneously on the basis of a rotation-inversion Hamiltonian which includes distortion constants up to the 12th power in the angular momentum and the Δk=±3 and Δk=±6 interaction terms. A set of effective parameters was also obtained for the v2=1 state adopting the same theoretical model. For the v2=2 and v4=1 states only a list of observed transitions is reported. The wavenumbers of all the assigned transitions were compared with their theoretically predicted values [S.N. Yurchenko, J. Quant. Spectrosc. Radiat. Transf., 2015, 152, 28]. The present results noticeably improve the wavenumber line list in the HITRAN data base [L. S. Rothman et al. J. Quant. Spectrosc. Radiat. Transf.,2013, 130, 4]. © 2017 Elsevier Ltd
BibTeX:
@article{Fusina2017,
  author = {Fusina, Luciano and DiLonardo, Gianfranco and Canè, Elisabetta and Predoi-Cross, Adriana and Rozario, Hoimonti and Herman, Michel},
  title = {The high resolution spectrum of 15NH3 in the far-infrared: Rotation-inversion transitions in the ground, v2=1, 2 and v4=1 states},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2017},
  volume = {203},
  pages = {417 – 424},
  doi = {10.1016/j.jqsrt.2017.01.021}
}
Gordon I, Rothman L, Hill C, Kochanov R, Tan Y, Bernath P, Birk M, Boudon V, Campargue A, Chance K, Drouin B, Flaud J-M, Gamache R, Hodges J, Jacquemart D, Perevalov V, Perrin A, Shine K, Smith M-A, Tennyson J, Toon G, Tran H, Tyuterev V, Barbe A, Császár A, Devi V, Furtenbacher T, Harrison J, Hartmann J-M, Jolly A, Johnson T, Karman T, Kleiner I, Kyuberis A, Loos J, Lyulin O, Massie S, Mikhailenko S, Moazzen-Ahmadi N, Müller H, Naumenko O, Nikitin A, Polyansky O, Rey M, Rotger M, Sharpe S, Sung K, Starikova E, Tashkun S, Auwera JV, Wagner G, Wilzewski J, Wcisło P, Yu S and Zak E (2017), "The HITRAN2016 molecular spectroscopic database", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 203, pp. 3 – 69.
Abstract: This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided. © 2017
BibTeX:
@article{Gordon2017,
  author = {Gordon, I.E. and Rothman, L.S. and Hill, C. and Kochanov, R.V. and Tan, Y. and Bernath, P.F. and Birk, M. and Boudon, V. and Campargue, A. and Chance, K.V. and Drouin, B.J. and Flaud, J.-M. and Gamache, R.R. and Hodges, J.T. and Jacquemart, D. and Perevalov, V.I. and Perrin, A. and Shine, K.P. and Smith, M.-A.H. and Tennyson, J. and Toon, G.C. and Tran, H. and Tyuterev, V.G. and Barbe, A. and Császár, A.G. and Devi, V.M. and Furtenbacher, T. and Harrison, J.J. and Hartmann, J.-M. and Jolly, A. and Johnson, T.J. and Karman, T. and Kleiner, I. and Kyuberis, A.A. and Loos, J. and Lyulin, O.M. and Massie, S.T. and Mikhailenko, S.N. and Moazzen-Ahmadi, N. and Müller, H.S.P. and Naumenko, O.V. and Nikitin, A.V. and Polyansky, O.L. and Rey, M. and Rotger, M. and Sharpe, S.W. and Sung, K. and Starikova, E. and Tashkun, S.A. and Auwera, J. Vander and Wagner, G. and Wilzewski, J. and Wcisło, P. and Yu, S. and Zak, E.J.},
  title = {The HITRAN2016 molecular spectroscopic database},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2017},
  volume = {203},
  pages = {3 – 69},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.jqsrt.2017.06.038}
}
Hartmann J-M, VanderAuwera J, Boulet C, Birot M, Dourges M-A, Toupance T, El Hamzaoui H, Ausset P, Carré Y, Kocon L, Capoen B and Bouazaoui M (2017), "Infrared absorption by molecular gases to probe porous materials and comparisons with other techniques", Microporous and Mesoporous Materials. Vol. 237, pp. 31 – 37.
Abstract: Infrared transmission spectra of several molecular gases inside three porous silica samples with pore sizes ranging from 7 nm to several tens of nm have been recorded with a Fourier transform spectrometer. Their analysis shows that consistent values of the percentage of open porosity and average pore size can be retrieved from these non intrusive nor destructive optical measurements. The samples have also been characterized using mercury intrusion/extrusion and the nitrogen sorption method. The results of these different probing techniques are in good agreement when the methods used are adapted to the involved pore size. This consistency demonstrates that light absorption by confined gases is a valuable porosimetry tool. © 2016 Elsevier Inc.
BibTeX:
@article{Hartmann2017,
  author = {Hartmann, J.-M. and VanderAuwera, J. and Boulet, C. and Birot, M. and Dourges, M.-A. and Toupance, T. and El Hamzaoui, H. and Ausset, P. and Carré, Y. and Kocon, L. and Capoen, B. and Bouazaoui, M.},
  title = {Infrared absorption by molecular gases to probe porous materials and comparisons with other techniques},
  journal = {Microporous and Mesoporous Materials},
  year = {2017},
  volume = {237},
  pages = {31 – 37},
  doi = {10.1016/j.micromeso.2016.09.014}
}
Hashemi R, Dudaryonok A, Lavrentieva N, Vandaele A, VanderAuwera J, Nikitin A, Tyuterev V, Sung K, Smith M, Devi V and Predoi-Cross A (2017), "Fourier Transform Spectroscopy of two trace gases namely Methane and Carbon monoxide for planetary and atmospheric research application", Journal of Physics: Conference Series. Vol. 810(1)
Abstract: Two atmospheric trace gases, namely methane and carbon monoxide have been considered in this study. Fourier transform absorption spectra of the 2-0 band of 12C16O mixed with CO2 have been recorded at total pressures from 156 to 1212 hPa and at 4 different temperatures between 240 K and 283 K. CO2 pressure-induced line broadening and line shift coefficients, and the associated temperature dependence have been measured in an multi-spectrum non-linear least squares analysis using Voigt profiles with an asymmetric profile due to line mixing. The measured CO2-broadening and CO2-shift parameters were compared with theoretical values, calculated by collaborators. In addition, the CO2-broadening and shift coefficients have been calculated for individual temperatures using the Exponential Power Gap (EPG) semi-empirical method. We also discuss the retrieved line shape parameters for Methane transitions in the spectral range known as the Methane Octad. We used high resolution spectra of pure methane and of dilute mixtures of methane in dry air, recorded with high signal to noise ratio at temperatures between 148 K and room temperature using the Bruker IFS 125 HR Fourier transform spectrometer (FTS) at the Jet Propulsion Laboratory, Pasadena, California. Theoretical calculations for line parameters have been performed and the results are compared with the previously published values and with the line parameters available in the GEISA2015 [1] and HITRAN2012 [2] databases. © Published under licence by IOP Publishing Ltd.
BibTeX:
@conference{Hashemi2017,
  author = {Hashemi, R. and Dudaryonok, A.S. and Lavrentieva, N.N. and Vandaele, A.C. and VanderAuwera, J. and Nikitin, A.V. and Tyuterev, V.I.G. and Sung, K. and Smith, M.A.H. and Devi, V.M. and Predoi-Cross, A.},
  title = {Fourier Transform Spectroscopy of two trace gases namely Methane and Carbon monoxide for planetary and atmospheric research application},
  journal = {Journal of Physics: Conference Series},
  year = {2017},
  volume = {810},
  number = {1},
  note = {All Open Access, Gold Open Access},
  doi = {10.1088/1742-6596/810/1/012008}
}
Jönsson P, Gaigalas G, Rynkun P, Radžiute L, Ekman J, Gustafsson S, Hartman H, Wang K, Godefroid M, Fischer CF, Grant I, Brage T and Del Zanna G (2017), "Multiconfiguration dirac-hartree-fock calculations with spectroscopic accuracy: Applications to astrophysics", Atoms. Vol. 5(2)
Abstract: Atomic data, such as wavelengths, spectroscopic labels, broadening parameters and transition rates, are necessary for many applications, especially in plasma diagnostics, and for interpreting the spectra of distant astrophysical objects. The experiment with its limited resources is unlikely to ever be able to provide a complete dataset on any atomic system. Instead, the bulk of the data must be calculated. Based on fundamental principles and well-justified approximations, theoretical atomic physics derives and implements algorithms and computational procedures that yield the desired data. We review progress and recent developments in fully-relativistic multiconfiguration Dirac-Hartree-Fock methods and show how large-scale calculations can give transition energies of spectroscopic accuracy, i.e., with an accuracy comparable to the one obtained from observations, as well as transition rates with estimated uncertainties of a few percent for a broad range of ions. Finally, we discuss further developments and challenges. © 2017 by the authors.
BibTeX:
@article{Joensson2017,
  author = {Jönsson, Per and Gaigalas, Gediminas and Rynkun, Pavel and Radžiute, Laima and Ekman, Jörgen and Gustafsson, Stefan and Hartman, Henrik and Wang, Kai and Godefroid, Michel and Fischer, Charlotte Froese and Grant, Ian and Brage, Tomas and Del Zanna, Giulio},
  title = {Multiconfiguration dirac-hartree-fock calculations with spectroscopic accuracy: Applications to astrophysics},
  journal = {Atoms},
  year = {2017},
  volume = {5},
  number = {2},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/atoms5020016}
}
Kas M, Loreau J, Liévin J and Vaeck N (2017), "Ab initio study of the neutral and anionic alkali and alkaline earth hydroxides: Electronic structure and prospects for sympathetic cooling of OH-", Journal of Chemical Physics. Vol. 146(19)
Abstract: We have performed a systematic ab initio study on alkali and alkaline earth hydroxide neutral (MOH) and anionic (MOH-) species where M = Li, Na, K, Rb, Cs or Be, Mg, Ca, Sr, Ba. The CCSD(T) method with extended basis sets and Dirac-Fock relativistic effective core potentials for the heavier atoms has been used to study their equilibrium geometries, interaction energies, electron affinities, electric dipole moment, and potential energy surfaces. All neutral and anionic species exhibit a linear shape with the exception of BeOH, BeOH-, and MgOH-, for which the equilibrium structure is found to be bent. Our analysis shows that the alkaline earth hydroxide anions are valence-bound whereas the alkali hydroxide anions are dipole bound. In the context of sympathetic cooling of OH- by collision with ultracold alkali and alkaline earth atoms, we investigate the 2D MOH- potential energy surfaces and the associative detachment reaction M + OH→- MOH + e-, which is the only energetically allowed reactive channel in the cold regime. We discuss the implication for the sympathetic cooling of OH- and conclude that Li and K are the best candidates for an ultracold buffer gas. © 2017 Author(s).
BibTeX:
@article{Kas2017,
  author = {Kas, Milaim and Loreau, Jérôme and Liévin, Jacques and Vaeck, Nathalie},
  title = {Ab initio study of the neutral and anionic alkali and alkaline earth hydroxides: Electronic structure and prospects for sympathetic cooling of OH-},
  journal = {Journal of Chemical Physics},
  year = {2017},
  volume = {146},
  number = {19},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/1.4983627}
}
Lacour J-L, Flamant C, Risi C, Clerbaux C and Coheur P-F (2017), "Importance of the Saharan heat low in controlling the North Atlantic free tropospheric humidity budget deduced from IASI δd observations", Atmospheric Chemistry and Physics. Vol. 17(15), pp. 9645 – 9663.
Abstract: The isotopic composition of water vapour in the North Atlantic free troposphere is investigated with Infrared Atmospheric Sounding Interferometer (IASI) measurements of the D/H ratio (δD) above the ocean. We show that in the vicinity of West Africa, the seasonality of δD is particularly strong (130 ‰), which is related with the influence of the Saharan heat low (SHL) during summertime. The SHL indeed largely influences the dynamic in that region by producing deep turbulent mixing layers, yielding a specific water vapour isotopic footprint. The influence of the SHL on the isotopic budget is analysed on various time and space scales and is shown to be large, highlighting the importance of the SHL dynamics on the moistening and the HDO enrichment of the free troposphere over the North Atlantic. The potential influence of the SHL is also investigated on the inter-annual scale as we also report important variations in δD above the Canary archipelago region. We interpret the variability in the enrichment, using backward trajectory analyses, in terms of the ratio of air masses coming from the North Atlantic and air masses coming from the African continent. Finally, the interest of IASI high sampling capabilities is further illustrated by presenting spatial distributions of δD and humidity above the North Atlantic from which we show that the different sources and dehydration pathways controlling the humidity can be disentangled thanks to the added value of δD observations. More generally, our results demonstrate the utility of δD observations obtained from the IASI sounder to gain insight into the hydrological cycle processes in the West African region. © Author(s) 2017.
BibTeX:
@article{Lacour2017,
  author = {Lacour, Jean-Lionel and Flamant, Cyrille and Risi, Camille and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Importance of the Saharan heat low in controlling the North Atlantic free tropospheric humidity budget deduced from IASI δd observations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2017},
  volume = {17},
  number = {15},
  pages = {9645 – 9663},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-17-9645-2017}
}
Launoy T, Béroff K, Chabot M, Martinet G, LePadellec A, Pino T, Bouneau S, Vaeck N, Liévin J, Féraud G, Loreau J and Mahajan T (2017), "Ion-pair dissociation of highly excited carbon clusters: Size and charge effects", Physical Review A. Vol. 95(2)
Abstract: We present measurements of ion-pair dissociation (IPD) of highly excited neutral and ionized carbon clusters Cn=2-5(q=0-3)+. The tool for producing these species was a high-velocity collision between Cn+ projectiles (v=2.25 a.u.) and helium atoms. The setup allowed us to detect in coincidence anionic and cationic fragments, event by event, leading to a direct and unambiguous identification of the IPD process. Compared with dissociation without anion emission, we found typical 10-4 IPD rates, not depending much on the size and charge of the (n,q) species. Exceptions were observed for C2+ and, to a lesser extent, C43+ whose IPDs were notably lower. We tentatively interpret IPDs of C2+ and C3+ by using a statistical approach based on the counting of final states allowed by energetic criteria. The model is able to furnish the right order of magnitude for the experimental IPD rates and to provide a qualitative explanation of the lower IPD rate observed in C2+. © 2017 American Physical Society.
BibTeX:
@article{Launoy2017,
  author = {Launoy, Thibaut and Béroff, Karine and Chabot, Marin and Martinet, Guillaume and LePadellec, Arnaud and Pino, Thomas and Bouneau, Sandra and Vaeck, Nathalie and Liévin, Jacques and Féraud, Géraldine and Loreau, Jérôme and Mahajan, Thejus},
  title = {Ion-pair dissociation of highly excited carbon clusters: Size and charge effects},
  journal = {Physical Review A},
  year = {2017},
  volume = {95},
  number = {2},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.95.022711}
}
Leifer I, Melton C, Tratt DM, Buckland KN, Clarisse L, Coheur P, Frash J, Gupta M, Johnson PD, Leen JB, VanDamme M, Whitburn S and Yurganov L (2017), "Remote sensing and in situ measurements of methane and ammonia emissions from a megacity dairy complex: Chino, CA", Environmental Pollution. Vol. 221, pp. 37 – 51.
Abstract: Methane (CH4) and ammonia (NH3) directly and indirectly affect the atmospheric radiative balance with the latter leading to aerosol generation. Both have important spectral features in the Thermal InfraRed (TIR) that can be studied by remote sensing, with NH3allowing discrimination of husbandry from other CH4sources. Airborne hyperspectral imagery was collected for the Chino Dairy Complex in the Los Angeles Basin as well as in situ CH4, carbon dioxide (CO2) and NH3data. TIR data showed good spatial agreement with in situ measurements and showed significant emissions heterogeneity between dairies. Airborne remote sensing mapped plume transport for ∼20 km downwind, documenting topographic effects on plume advection. Repeated multiple gas in situ measurements showed that emissions were persistent on half-year timescales. Inversion of one dairy plume found annual emissions of 4.1 × 105 kg CH4, 2.2 × 105 kg NH3, and 2.3 × 107 kg CO2, suggesting 2300, 4000, and 2100 head of cattle, respectively, and Chino Dairy Complex emissions of 42 Gg CH4and 8.4 Gg NH3implying ∼200k cows, ∼30% more than Peischl et al. (2013) estimated for June 2010. Far-field data showed chemical conversion and/or deposition of Chino NH3occurs within the confines of the Los Angeles Basin on a four to six h timescale, faster than most published rates, and likely from higher Los Angeles oxidant loads. Satellite observations from 2011 to 2014 confirmed that observed in situ transport patterns were representative and suggests much of the Chino Dairy Complex emissions are driven towards eastern Orange County, with a lesser amount transported to Palm Springs, CA. Given interest in mitigating husbandry health impacts from air pollution emissions, this study highlights how satellite observations can be leveraged to understand exposure and how multiple gas in situ emissions studies can inform on best practices given that emissions reduction of one gas could increase those of others. © 2016 Elsevier Ltd
BibTeX:
@article{Leifer2017,
  author = {Leifer, Ira and Melton, Christopher and Tratt, David M. and Buckland, Kerry N. and Clarisse, Lieven and Coheur, Pierre and Frash, Jason and Gupta, Manish and Johnson, Patrick D. and Leen, J. Brian and VanDamme, Martin and Whitburn, Simon and Yurganov, Leonid},
  title = {Remote sensing and in situ measurements of methane and ammonia emissions from a megacity dairy complex: Chino, CA},
  journal = {Environmental Pollution},
  year = {2017},
  volume = {221},
  pages = {37 – 51},
  doi = {10.1016/j.envpol.2016.09.083}
}
Li Y, Thompson TM, VanDamme M, Chen X, Benedict KB, Shao Y, Day D, Boris A, Sullivan AP, Ham J, Whitburn S, Clarisse L, Coheur P-F and Collett JL (2017), "Temporal and spatial variability of ammonia in urban and agricultural regions of northern Colorado, United States", Atmospheric Chemistry and Physics. Vol. 17(10), pp. 6197 – 6213.
Abstract: Concentrated agricultural activities and animal feeding operations in the northeastern plains of Colorado represent an important source of atmospheric ammonia (NH3). The NH3 from these sources contributes to regional fine particle formation and to nitrogen deposition to sensitive ecosystems in Rocky Mountain National Park (RMNP), located ∼80 km to the west. In order to better understand temporal and spatial differences in NH3 concentrations in this source region, weekly concentrations of NH3 were measured at 14 locations during the summers of 2010 to 2015 using Radiello passive NH3 samplers. Weekly (biweekly in 2015) average NH3 concentrations ranged from 2.66 to 42.7μ-3, with the highest concentrations near large concentrated animal feeding operations (CAFOs). The annual summertime mean NH3 concentrations were stable in this region from 2010 to 2015, providing a baseline against which concentration changes associated with future changes in regional NH3 emissions can be assessed. Vertical profiles of NH3 were also measured on the 300 m Boulder Atmospheric Observatory (BAO) tower throughout 2012. The highest NH3 concentration along the vertical profile was always observed at the 10 m height (annual average concentration of 4.63 μgm-3), decreasing toward the surface (4.35g μg-3) and toward higher altitudes (1.93g μg-3). The NH3 spatial distributions measured using the passive samplers are compared with NH3 columns retrieved by the Infrared Atmospheric Sounding Interferometer (IASI) satellite and concentrations simulated by the Comprehensive Air Quality Model with Extensions (CAMx). The satellite comparison adds to a growing body of evidence that IASI column retrievals of NH3 provide very useful insight into regional variability in atmospheric NH3, in this case even in a region with strong local sources and sharp spatial gradients. The CAMx comparison indicates that the model does a reasonable job simulating NH3 concentrations near sources but tends to underpredict concentrations at locations farther downwind. Excess NH3 deposition by the model is hypothesized as a possible explanation for this trend. © 2017 Author(s).
BibTeX:
@article{Li2017,
  author = {Li, Yi and Thompson, Tammy M. and VanDamme, Martin and Chen, Xi and Benedict, Katherine B. and Shao, Yixing and Day, Derek and Boris, Alexandra and Sullivan, Amy P. and Ham, Jay and Whitburn, Simon and Clarisse, Lieven and Coheur, Pierre-François and Collett, Jeffrey L.},
  title = {Temporal and spatial variability of ammonia in urban and agricultural regions of northern Colorado, United States},
  journal = {Atmospheric Chemistry and Physics},
  year = {2017},
  volume = {17},
  number = {10},
  pages = {6197 – 6213},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-17-6197-2017}
}
Mahieu E, Bader W, Bovy B, Demoulin P, Flock O, Franco B, Lejeune B, Prignon M, Roland G and Servais C (2017), "Monitoring of the earth's atmosphere from the Jungfraujoch station: A journey started by the Liège team is more than 65 years!; [Surveillance De L'atmosphère Terrestre Depuis La Station Du Jungfraujoch : Une Épopée Liégeoise Entamée Voici Plus De 65 Ans !]", BSGLg. Vol. 68(1), pp. 119 – 130.
Abstract: It is in the early 1950s that researchers from the University of Liège started to investigate the Earth's atmosphere from the Jungfraujoch scientific station, in the Swiss Alps, at a time when concerns related to atmospheric composition changes were nonexistent. Since then, a worldwide unique infrared observational data base has been carefully collected. The exploitation of these observations has allowed constituting multi-decadal time series crucial for the characterization of the changes that affected our atmosphere and for the identification of their causes. In this paper, we first remind about the successive steps which led to establishing the observational program of the Liège team at the Jungfraujoch and we evoke important findings which justified its continuation. Then we present some recent results relevant to the Montreal and Kyoto Protocols, or related to the monitoring of air quality. © 2017 Societe Geographique de Liege. All rights reserved.
BibTeX:
@article{Mahieu2017,
  author = {Mahieu, Emmanuel and Bader, Whitney and Bovy, Benoît and Demoulin, Philippe and Flock, Olivier and Franco, Bruno and Lejeune, Bernard and Prignon, Maxime and Roland, Ginette and Servais, Christian},
  title = {Monitoring of the earth's atmosphere from the Jungfraujoch station: A journey started by the Liège team is more than 65 years!; [Surveillance De L'atmosphère Terrestre Depuis La Station Du Jungfraujoch : Une Épopée Liégeoise Entamée Voici Plus De 65 Ans !]},
  journal = {BSGLg},
  year = {2017},
  volume = {68},
  number = {1},
  pages = {119 – 130}
}
Malavelle FF, Haywood JM, Jones A, Gettelman A, Clarisse L, Bauduin S, Allan RP, Karset IHH, Kristjánsson JE, Oreopoulos L, Cho N, Lee D, Bellouin N, Boucher O, Grosvenor DP, Carslaw KS, Dhomse S, Mann GW, Schmidt A, Coe H, Hartley ME, Dalvi M, Hill AA, Johnson BT, Johnson CE, Knight JR, O'Connor FM, Stier P, Myhre G, Platnick S, Stephens GL, Takahashi H and Thordarson T (2017), "Strong constraints on aerosol-cloud interactions from volcanic eruptions", Nature. Vol. 546(7659), pp. 485 – 491.
Abstract: Aerosols have a potentially large effect on climate, particularly through their interactions with clouds, but the magnitude of this effect is highly uncertain. Large volcanic eruptions produce sulfur dioxide, which in turn produces aerosols; these eruptions thus represent a natural experiment through which to quantify aerosol-cloud interactions. Here we show that the massive 2014-2015 fissure eruption in Holuhraun, Iceland, reduced the size of liquid cloud droplets - consistent with expectations - but had no discernible effect on other cloud properties. The reduction in droplet size led to cloud brightening and global-mean radiative forcing of around -0.2 watts per square metre for September to October 2014. Changes in cloud amount or cloud liquid water path, however, were undetectable, indicating that these indirect effects, and cloud systems in general, are well buffered against aerosol changes. This result will reduce uncertainties in future climate projections, because we are now able to reject results from climate models with an excessive liquid-water-path response. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
BibTeX:
@article{Malavelle2017,
  author = {Malavelle, Florent F. and Haywood, Jim M. and Jones, Andy and Gettelman, Andrew and Clarisse, Lieven and Bauduin, Sophie and Allan, Richard P. and Karset, Inger Helene H. and Kristjánsson, Jón Egill and Oreopoulos, Lazaros and Cho, Nayeong and Lee, Dongmin and Bellouin, Nicolas and Boucher, Olivier and Grosvenor, Daniel P. and Carslaw, Ken S. and Dhomse, Sandip and Mann, Graham W. and Schmidt, Anja and Coe, Hugh and Hartley, Margaret E. and Dalvi, Mohit and Hill, Adrian A. and Johnson, Ben T. and Johnson, Colin E. and Knight, Jeff R. and O'Connor, Fiona M. and Stier, Philip and Myhre, Gunnar and Platnick, Steven and Stephens, Graeme L. and Takahashi, Hanii and Thordarson, Thorvaldur},
  title = {Strong constraints on aerosol-cloud interactions from volcanic eruptions},
  journal = {Nature},
  year = {2017},
  volume = {546},
  number = {7659},
  pages = {485 – 491},
  note = {All Open Access, Green Open Access},
  doi = {10.1038/nature22974}
}
Moussallam Y, Tamburello G, Peters N, Apaza F, Schipper CI, Curtis A, Aiuppa A, Masias P, Boichu M, Bauduin S, Barnie T, Bani P, Giudice G and Moussallam M (2017), "Volcanic gas emissions and degassing dynamics at Ubinas and Sabancaya volcanoes; implications for the volatile budget of the central volcanic zone", Journal of Volcanology and Geothermal Research. Vol. 343, pp. 181 – 191.
Abstract: Emission of volcanic gas is thought to be the dominant process by which volatiles transit from the deep earth to the atmosphere. Volcanic gas emissions, remain poorly constrained, and volcanoes of Peru are entirely absent from the current global dataset. In Peru, Sabancaya and Ubinas volcanoes are by far the largest sources of volcanic gas. Here, we report the first measurements of the compositions and fluxes of volcanic gases emitted from these volcanoes. The measurements were acquired in November 2015. We determined an average SO2 flux of 15.3 ± 2.3 kg s− 1 (1325-ton day− 1) at Sabancaya and of 11.4 ± 3.9 kg s− 1 (988-ton day− 1) at Ubinas using scanning ultraviolet spectroscopy and dual UV camera systems. In-situ Multi-GAS analyses yield molar proportions of H2O, CO2, SO2, H2S and H2 gases of 73, 15, 10 1.15 and 0.15 mol% at Sabancaya and of 96, 2.2, 1.2 and 0.05 mol% for H2O, CO2, SO2 and H2S at Ubinas. Together, these data imply cumulative fluxes for both volcanoes of 282, 30, 27, 1.2 and 0.01 kg s− 1 of H2O, CO2, SO2, H2S and H2 respectively. Sabancaya and Ubinas volcanoes together contribute about 60% of the total CO2 emissions from the Central Volcanic zone, and dominate by far the total revised volatile budget of the entire Central Volcanic Zone of the Andes. © 2017 Elsevier B.V.
BibTeX:
@article{Moussallam2017,
  author = {Moussallam, Yves and Tamburello, Giancarlo and Peters, Nial and Apaza, Fredy and Schipper, C. Ian and Curtis, Aaron and Aiuppa, Alessandro and Masias, Pablo and Boichu, Marie and Bauduin, Sophie and Barnie, Talfan and Bani, Philipson and Giudice, Gaetano and Moussallam, Manuel},
  title = {Volcanic gas emissions and degassing dynamics at Ubinas and Sabancaya volcanoes; implications for the volatile budget of the central volcanic zone},
  journal = {Journal of Volcanology and Geothermal Research},
  year = {2017},
  volume = {343},
  pages = {181 – 191},
  note = {All Open Access, Green Open Access},
  doi = {10.1016/j.jvolgeores.2017.06.027}
}
Paulot F, Paynter D, Ginoux P, Naik V, Whitburn S, VanDamme M, Clarisse L, Coheur P-F and Horowitz L (2017), "Gas-aerosol partitioning of ammonia in biomass burning plumes: Implications for the interpretation of spaceborne observations of ammonia and the radiative forcing of ammonium nitrate", Geophysical Research Letters. Vol. 44(15), pp. 8084 – 8093.
Abstract: Satellite-derived enhancement ratios of NH3 relative to CO column burden (ERNH3/CO) in fires over Alaska, the Amazon, and South Equatorial Africa are 35, 45, and 70% lower than the corresponding ratio of their emissions factors (ERNH3/CO) from biomass burning derived from in situ observations. Simulations performed using the Geophysical Fluid Dynamics Laboratory AM3 global chemistry-climate model show that these regional differences may not entirely stem from an overestimate of NH3 emissions but rather from changes in the gas-aerosol partitioning of NH3 to NH4+. Differences between (ERNH3/CO) and (EFNH3/CO) are largest in regions where is high, consistent with the production of NH4NO3. Biomass burning is estimated to contribute 11–23% of the global burden and direct radiative effect (DRE) of NH4NO3 (−15 to −28 mW m−2), despite accounting for less than 6% of the global source of NH3. Production of NH4NO3 is largely concentrated over the Amazon and South Equatorial Africa, where its DRE can reach −1.9 W m−2 during the biomass burning season. ©2017. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Paulot2017,
  author = {Paulot, F. and Paynter, D. and Ginoux, P. and Naik, V. and Whitburn, S. and VanDamme, M. and Clarisse, L. and Coheur, P.-F. and Horowitz, L.W.},
  title = {Gas-aerosol partitioning of ammonia in biomass burning plumes: Implications for the interpretation of spaceborne observations of ammonia and the radiative forcing of ammonium nitrate},
  journal = {Geophysical Research Letters},
  year = {2017},
  volume = {44},
  number = {15},
  pages = {8084 – 8093},
  doi = {10.1002/2017GL074215}
}
Pommier M, Clerbaux C and Coheur P-F (2017), "Determination of enhancement ratios of HCOOH relative to CO in biomass burning plumes by the Infrared Atmospheric Sounding Interferometer (IASI)", Atmospheric Chemistry and Physics. Vol. 17(18), pp. 11089 – 11105.
Abstract: Formic acid (HCOOH) concentrations are often underestimated by models, and its chemistry is highly uncertain. HCOOH is, however, among the most abundant atmospheric volatile organic compounds, and it is potentially responsible for rain acidity in remote areas. HCOOH data from the Infrared Atmospheric Sounding Interferometer (IASI) are analyzed from 2008 to 2014 to estimate enhancement ratios from biomass burning emissions over seven regions. Fire-affected HCOOH and CO total columns are defined by combining total columns from IASI, geographic location of the fires from Moderate Resolution Imaging Spectroradiometer (MODIS), and the surface wind speed field from the European Centre for Medium-Range Weather Forecasts (ECMWF). Robust correlations are found between these fire-affected HCOOH and CO total columns over the selected biomass burning regions, allowing the calculation of enhancement ratios equal to 7.30g × g 10g'3g ±g 0.08g × g 10g'3g molg molg'1 over Amazonia (AMA), 11.10g × g 10g'3g ±g 1.37g × g 10g'3g molg molg'1 over Australia (AUS), 6.80g × g 10g'3g ±g 0.44g × g 10g'3g molg molg'1 over India (IND), 5.80g × g 10g'3g ±g 0.15g × g 10g'3g molg molg'1 over Southeast Asia (SEA), 4.00g × g 10g'3g ±g 0.19g × g 10g'3g molg molg'1 over northern Africa (NAF), 5.00g × g 10g'3g ±g 0.13g × g 10g'3g molg molg'1 over southern Africa (SAF), and 4.40g × g 10g'3g ±g 0.09g × g 10g'3g molg molg'1 over Siberia (SIB), in a fair agreement with previous studies. In comparison with referenced emission ratios, it is also shown that the selected agricultural burning plumes captured by IASI over India and Southeast Asia correspond to recent plumes where the chemistry or the sink does not occur. An additional classification of the enhancement ratios by type of fuel burned is also provided, showing a diverse origin of the plumes sampled by IASI, especially over Amazonia and Siberia. The variability in the enhancement ratios by biome over the different regions show that the levels of HCOOH and CO do not only depend on the fuel types. © Author(s) 2017.
BibTeX:
@article{Pommier2017,
  author = {Pommier, Matthieu and Clerbaux, Cathy and Coheur, Pierre-Francois},
  title = {Determination of enhancement ratios of HCOOH relative to CO in biomass burning plumes by the Infrared Atmospheric Sounding Interferometer (IASI)},
  journal = {Atmospheric Chemistry and Physics},
  year = {2017},
  volume = {17},
  number = {18},
  pages = {11089 – 11105},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-17-11089-2017}
}
Sutcliffe B and Woolley RG (2017), "The position of the clamped nuclei electronic hamiltonian in quantum mechanics", Handbook of Computational Chemistry. , pp. 69 – 121.
Abstract: Arguments are advanced to support the view that at present it is not possible to derive molecular structure from the full quantum mechanical Coulomb Hamiltonian associated with a given molecular formula that is customarily regarded as representing the molecule in terms of its constituent electrons and nuclei. However molecular structure may be identified provided that some additional chemically motivated assumptions that lead to the clamped nuclei Hamiltonian are added to the quantum mechanical account. © Springer International Publishing Switzerland 2017.
BibTeX:
@book{Sutcliffe2017,
  author = {Sutcliffe, Brian and Woolley, R. Guy},
  title = {The position of the clamped nuclei electronic hamiltonian in quantum mechanics},
  journal = {Handbook of Computational Chemistry},
  year = {2017},
  pages = {69 – 121},
  doi = {10.1007/978-3-319-27282-5_2}
}
Troian-Gautier L, Mugeniwabagara E, Fusaro L, Cauët E, Kirsch-De Mesmaeker A and Luhmer M (2017), "Photo-CIDNP Reveals Different Protonation Sites Depending on the Primary Step of the Photoinduced Electron-/Proton-Transfer Process with Ru(II) Polyazaaromatic Complexes", Journal of the American Chemical Society. Vol. 139(42), pp. 14909 – 14912.
Abstract: The excited-state quenching of [Ru(TAP)2(HAT)]2+ (TAP = 1,4,5,8-tetraazaphenanthrene, HAT= 1,4,5,8,9,12-hexaazatriphenylene) by hydroquinone (H2Q), N-acetyl-tyrosine (N-Ac-Tyr) or guanosine-5′-monophosphate (GMP) was investigated at various pH values. The quenching occurs via electron/proton transfer, as evidenced by transient absorption spectroscopy and confirmed by 1H photochemically induced dynamic nuclear polarization (photo-CIDNP). Reductive quenching also occurs in strongly acidic solution despite a much shorter lifetime of the protonated excited-state complex. Photo-CIDNP revealed a different mechanism at low pH, involving protonation before electron transfer and yielding a distinct protonated monoreduced complex. The experimental photo-CIDNP patterns are consistent with density functional theory calculations. This work highlights the power of 1H photo-CIDNP for characterizing, at the atomic level, transient species involved in electron-transfer processes. © 2017 American Chemical Society.
BibTeX:
@article{TroianGautier2017,
  author = {Troian-Gautier, Ludovic and Mugeniwabagara, Epiphanie and Fusaro, Luca and Cauët, Emilie and Kirsch-De Mesmaeker, Andrée and Luhmer, Michel},
  title = {Photo-CIDNP Reveals Different Protonation Sites Depending on the Primary Step of the Photoinduced Electron-/Proton-Transfer Process with Ru(II) Polyazaaromatic Complexes},
  journal = {Journal of the American Chemical Society},
  year = {2017},
  volume = {139},
  number = {42},
  pages = {14909 – 14912},
  doi = {10.1021/jacs.7b09513}
}
Tzompa-Sosa Z, Mahieu E, Franco B, Keller C, Turner A, Helmig D, Fried A, Richter D, Weibring P, Walega J, Yacovitch T, Herndon S, Blake D, Hase F, Hannigan J, Conway S, Strong K, Schneider M and Fischer E (2017), "Revisiting global fossil fuel and biofuel emissions of ethane", Journal of Geophysical Research. Vol. 122(4), pp. 2493 – 2512.
Abstract: Recent measurements over the Northern Hemisphere indicate that the long-term decline in the atmospheric burden of ethane (C2H6) has ended and the abundance increased dramatically between 2010 and 2014. The rise in C2H6 atmospheric abundances has been attributed to oil and natural gas extraction in North America. Existing global C2H6 emission inventories are based on outdated activity maps that do not account for current oil and natural gas exploitation regions. We present an updated global C2H6 emission inventory based on 2010 satellite-derived CH4 fluxes with adjusted C2H6 emissions over the U.S. from the National Emission Inventory (NEI 2011). We contrast our global 2010 C2H6 emission inventory with one developed for 2001. The C2H6 difference between global anthropogenic emissions is subtle (7.9 versus 7.2 Tg yr-1), but the spatial distribution of the emissions is distinct. In the 2010 C2H6 inventory, fossil fuel sources in the Northern Hemisphere represent half of global C2H6 emissions and 95% of global fossil fuel emissions. Over the U.S., unadjusted NEI 2011 C2H6 emissions produce mixing ratios that are 14-50% of those observed by aircraft observations (2008-2014). When the NEI 2011 C2H6 emission totals are scaled by a factor of 1.4, the Goddard Earth Observing System Chem model largely reproduces a regional suite of observations, with the exception of the central U.S., where it continues to underpredict observed mixing ratios in the lower troposphere. We estimate monthly mean contributions of fossil fuel C2H6 emissions to ozone and peroxyacetyl nitrate surface mixing ratios over North America of   1% and  8%, respectively. © 2017. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{TzompaSosa2017,
  author = {Tzompa-Sosa, Z.A. and Mahieu, E. and Franco, B. and Keller, C.A. and Turner, A.J. and Helmig, D. and Fried, A. and Richter, D. and Weibring, P. and Walega, J. and Yacovitch, T.I. and Herndon, S.C. and Blake, D.R. and Hase, F. and Hannigan, J.W. and Conway, S. and Strong, K. and Schneider, M. and Fischer, E.V.},
  title = {Revisiting global fossil fuel and biofuel emissions of ethane},
  journal = {Journal of Geophysical Research},
  year = {2017},
  volume = {122},
  number = {4},
  pages = {2493 – 2512},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1002/2016JD025767}
}
VanDamme M, Whitburn S, Clarisse L, Clerbaux C, Hurtmans D and Coheur P-F (2017), "Version 2 of the IASI NH3 neural network retrieval algorithm: Near-real-time and reanalysed datasets", Atmospheric Measurement Techniques. Vol. 10(12), pp. 4905 – 4914.
Abstract: Recently, Whitburn et al.(2016) presented a neural-network-based algorithm for retrieving atmospheric ammonia (NH3) columns from Infrared Atmospheric Sounding Interferometer (IASI) satellite observations. In the past year, several improvements have been introduced, and the resulting new baseline version, Artificial Neural Network for IASI (ANNI)-NH3-v2.1, is documented here. One of the main changes to the algorithm is that separate neural networks were trained for land and sea observations, resulting in a better training performance for both groups. By reducing and transforming the input parameter space, performance is now also better for observations associated with favourable sounding conditions (i.e. enhanced thermal contrasts). Other changes relate to the introduction of a bias correction over land and sea and the treatment of the satellite zenith angle. In addition to these algorithmic changes, new recommendations for post-filtering the data and for averaging data in time or space are formulated. We also introduce a second dataset (ANNI-NH3-v2.1R-I) which relies on ERA-Interim ECMWF meteorological input data, along with surface temperature retrieved from a dedicated network, rather than the operationally provided Eumetsat IASI Level 2 (L2) data used for the standard near-real-time version. The need for such a dataset emerged after a series of sharp discontinuities were identified in the NH3 time series, which could be traced back to incremental changes in the IASI L2 algorithms for temperature and clouds. The reanalysed dataset is coherent in time and can therefore be used to study trends. Furthermore, both datasets agree reasonably well in the mean on recent data, after the date when the IASI meteorological L2 version 6 became operational (30 September 2014). © Author(s) 2017. This work is distributed under the Creative Commons Attribution 4.0 License.
BibTeX:
@article{VanDamme2017,
  author = {VanDamme, Martin and Whitburn, Simon and Clarisse, Lieven and Clerbaux, Cathy and Hurtmans, Daniel and Coheur, Pierre-François},
  title = {Version 2 of the IASI NH3 neural network retrieval algorithm: Near-real-time and reanalysed datasets},
  journal = {Atmospheric Measurement Techniques},
  year = {2017},
  volume = {10},
  number = {12},
  pages = {4905 – 4914},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-10-4905-2017}
}
Vanfleteren T, Földes T, Herman M, Liévin J, Loreau J and Coudert LH (2017), "Experimental and theoretical investigations of H2O-Ar", Journal of Chemical Physics. Vol. 147(1)
Abstract: We have used continuous-wave cavity ring-down spectroscopy to record the spectrum of H2O-Ar in the 2OH excitation range of H2O. 24 sub-bands have been observed. Their rotational structure (Trot = 12 K) is analyzed and the lines are fitted separately for ortho and para species together with microwave and far infrared data from the literature, with a unitless standard deviation σ=0.98 and 1.31, respectively. Their vibrational analysis is supported by a theoretical input based on an intramolecular potential energy surface obtained through ab initio calculations and computation of the rotational energy of sub-states of the complex with the water monomer in excited vibrational states up to the first hexad. For the ground and (010) vibrational states, the theoretical results agree well with experimental energies and rotational constants in the literature. For the excited vibrational states of the first hexad, they guided the assignment of the observed sub-bands. The upper state vibrational predissociation lifetime is estimated to be 3 ns from observed spectral linewidths. © 2017 Author(s).
BibTeX:
@article{Vanfleteren2017,
  author = {Vanfleteren, Thomas and Földes, Tomas and Herman, Michel and Liévin, Jacques and Loreau, Jérôme and Coudert, Laurent H.},
  title = {Experimental and theoretical investigations of H2O-Ar},
  journal = {Journal of Chemical Physics},
  year = {2017},
  volume = {147},
  number = {1},
  doi = {10.1063/1.4990738}
}
Vanfleteren T, Földes T, Rizopoulos A and Herman M (2017), "Overtone, 2OH spectroscopy of H2O[sbnd]Kr", Journal of Molecular Spectroscopy. Vol. 342, pp. 92 – 99.
Abstract: We have used continuous-wave cavity ring-down spectroscopy to record the spectrum of H2O[sbnd]Kr in the 2OH excitation range of H2O. 11 sub-bands have been observed for the main krypton isotope, 84 Kr. Their rotational structure (Trot=18 K) is analyzed and the lines fitted together with literature microwave data, with a unitless standard deviation σ=0.86 and 1.32 for ortho and para species, respectively. 4 more sub-bands are observed for the three other isotopes and are also analyzed. The upper state vibrational predissociation lifetime is estimated to 4 ns from observed spectral linewidths. © 2017 Elsevier Inc.
BibTeX:
@article{Vanfleteren2017a,
  author = {Vanfleteren, Thomas and Földes, Tomas and Rizopoulos, Athéna and Herman, Michel},
  title = {Overtone, 2OH spectroscopy of H2O[sbnd]Kr},
  journal = {Journal of Molecular Spectroscopy},
  year = {2017},
  volume = {342},
  pages = {92 – 99},
  note = {All Open Access, Bronze Open Access},
  doi = {10.1016/j.jms.2017.06.010}
}
Wang K, Jönsson P, Ekman J, Brage T, Chen CY, Fischer CF, Gaigalas G and Godefroid M (2017), "Comment on "theoretical Confirmation of the Low Experimental 3C/3D f -Value Ratio in Fe xvii "", Physical Review Letters. Vol. 119(18)
Abstract: A Comment on the Letter by Mendoza and Bautista [Phys. Rev. Lett. 118, 163002 (2017)PRLTAO0031-900710.1103/PhysRevLett.118.163002]. © 2017 American Physical Society.
BibTeX:
@article{Wang2017,
  author = {Wang, Kai and Jönsson, Per and Ekman, Jörgen and Brage, Tomas and Chen, Chong Yang and Fischer, Charlotte Froese and Gaigalas, Gediminas and Godefroid, Michel},
  title = {Comment on "theoretical Confirmation of the Low Experimental 3C/3D f -Value Ratio in Fe xvii "},
  journal = {Physical Review Letters},
  year = {2017},
  volume = {119},
  number = {18},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevLett.119.189301}
}
Wang K, Jönsson P, Ekman J, Gaigalas G, Godefroid M, Si R, Chen Z, Li S, Chen C and Yan J (2017), "Extended Calculations of Spectroscopic Data: Energy Levels, Lifetimes, and Transition Rates for O-like Ions from Cr xxiii", Astrophysical Journal, Supplement Series. Vol. 229(2)
Abstract: Employing two state-of-the-art methods, multiconfiguration Dirac-Hartree-Fock and second-order many-body perturbation theory, the excitation energies and lifetimes for the lowest 200 states of the 2s22p4, 2s2p5, 2p6, 2s22p33s, 2s22p33p, 2s22p33d, 2s2p43s, 2s2p43p, and 2s2p43d configurations, and multipole (electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2)) transition rates, line strengths, and oscillator strengths among these states are calculated for each O-like ion, from Cr XVII to Zn XXIII. Our two data sets are compared with the National Institute of Standards and Technology and CHIANTI compiled values, and previous calculations. The data are accurate enough for identification and deblending of new emission lines from the Sun and other astrophysical sources. The amount of high-accuracy data is significantly increased for the n = 3 states of several O-like ions of astrophysical interest, where experimental data are very scarce. © 2017. The American Astronomical Society. All rights reserved.
BibTeX:
@article{Wang2017a,
  author = {Wang, K. and Jönsson, P. and Ekman, J. and Gaigalas, G. and Godefroid, M.R. and Si, R. and Chen, Z.B. and Li, S. and Chen, C.Y. and Yan, J.},
  title = {Extended Calculations of Spectroscopic Data: Energy Levels, Lifetimes, and Transition Rates for O-like Ions from Cr xxiii},
  journal = {Astrophysical Journal, Supplement Series},
  year = {2017},
  volume = {229},
  number = {2},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.3847/1538-4365/aa6847}
}
Wespes C, Hurtmans D, Clerbaux C and Coheur P-F (2017), "O3 variability in the troposphere as observed by IASI over 2008-2016: Contribution of atmospheric chemistry and dynamics", Journal of Geophysical Research. Vol. 122(4), pp. 2429 – 2451.
Abstract: We analyze the ozone (O3) variability in the troposphere (from ground to 300 hPa) using 8 years (January 2008 to March 2016) of O3 profile measurements provided by the Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp satellite. The capability of IASI to monitor the year-to-year variability in that layer is examined first in terms of vertical sensitivity, a priori contribution, and correlations in the deseasonalized anomalies with the upper layers. We present global patterns of the main geophysical drivers (e.g., solar flux, Quasi-biennal Oscillation-QBO, North Atlantic Oscillation-NAO, and El Niño-Southern Oscillation-ENSO) of IASI O3 variations, obtained by applying appropriate annual and seasonal multivariate regression models on time series of spatially gridded averaged O3. The results show that the models are able to explain most of the O3 variability captured by IASI. Large O3 changes in the North Arctic/Euro-Atlantic sector and over the equatorial band are attributed to the NAO and the QBO effects, respectively. ENSO is modeled as the main contributor to the O3 variations in the tropical band where direct effects of warm and cool ENSO phases are highlighted with a clear tropical-extratropical gradient. A strong west-east gradient in the tropics is also found and likely reflects an indirect effect related to ENSO dry conditions. Finally, we also show that the ENSO perturbs the O3 variability far from the tropics into middle and high latitudes where a significant 4-month time-lag in the response of O3 to ENSO is identified for the first time. © 2017. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Wespes2017,
  author = {Wespes, C. and Hurtmans, D. and Clerbaux, C. and Coheur, P.-F.},
  title = {O3 variability in the troposphere as observed by IASI over 2008-2016: Contribution of atmospheric chemistry and dynamics},
  journal = {Journal of Geophysical Research},
  year = {2017},
  volume = {122},
  number = {4},
  pages = {2429 – 2451},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1002/2016JD025875}
}
Whitburn S, VanDamme M, Clarisse L, Hurtmans D, Clerbaux C and Coheur P-F (2017), "IASI-derived NH3 enhancement ratios relative to CO for the tropical biomass burning regions", Atmospheric Chemistry and Physics. Vol. 17(19), pp. 12239 – 12252.
Abstract: Vegetation fires are a major source of ammonia (NH3) in the atmosphere. Their emissions are mainly estimated using bottom-up approaches that rely on uncertain emission factors. In this study, we derive new biome-specific NH3 enhancement ratios relative to carbon monoxide (CO), ERNH3 / CO (directly related to the emission factors), from the measurements of the IASI sounder onboard the Metop-A satellite. This is achieved for large tropical regions and for an 8-year period (2008-2015). We find substantial differences in the ERNH3 / CO ratios between the biomes studied, with calculated values ranging from 7 × 10-3 to 23 × 10-3. For evergreen broadleaf forest these are typically 50-75% higher than for woody savanna and savanna biomes. This variability is attributed to differences in fuel types and size and is in line with previous studies. The analysis of the spatial and temporal distribution of the ERNH3 / CO ratio also reveals a (sometimes large) within-biome variability. On a regional level, woody savanna shows, for example, a mean ERNH3 / CO ratio for the region of Africa south of the Equator that is 40-75% lower than in the other five regions studied, probably reflecting regional differences in fuel type and burning conditions. The same variability is also observed on a yearly basis, with a peak in the ERNH3 / CO ratio observed for the year 2010 for all biomes. These results highlight the need for the development of dynamic emission factors that take into better account local variations in fuel type and fire conditions. We also compare the IASI-derived ERNH3 / CO ratio with values reported in the literature, usually calculated from ground-based or airborne measurements. We find general good agreement in the referenced ERNH3 / CO ratio except for cropland, for which the ERNH3 / CO ratio shows an underestimation of about 2-2.5 times. © 2017 Author(s).
BibTeX:
@article{Whitburn2017,
  author = {Whitburn, Simon and VanDamme, Martin and Clarisse, Lieven and Hurtmans, Daniel and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {IASI-derived NH3 enhancement ratios relative to CO for the tropical biomass burning regions},
  journal = {Atmospheric Chemistry and Physics},
  year = {2017},
  volume = {17},
  number = {19},
  pages = {12239 – 12252},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-17-12239-2017}
}
Wraith C, Yang X, Xie L, Babcock C, Bieroń J, Billowes J, Bissell M, Blaum K, Cheal B, Filippin L, Garcia Ruiz R, Gins W, Grob L, Gaigalas G, Godefroid M, Gorges C, Heylen H, Honma M, Jönsson P, Kaufmann S, Kowalska M, Krämer J, Malbrunot-Ettenauer S, Neugart R, Neyens G, Nörtershäuser W, Nowacki F, Otsuka T, Papuga J, Sánchez R, Tsunoda Y and Yordanov D (2017), "Evolution of nuclear structure in neutron-rich odd-Zn isotopes and isomers", Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. Vol. 771, pp. 385 – 391.
Abstract: Collinear laser spectroscopy was performed on Zn (Z=30) isotopes at ISOLDE, CERN. The study of hyperfine spectra of nuclei across the Zn isotopic chain, N=33–49, allowed the measurement of nuclear spins for the ground and isomeric states in odd-A neutron-rich nuclei up to N=50. Exactly one long-lived (&#x003E;10 ms) isomeric state has been established in each 69–79Zn isotope. The nuclear magnetic dipole moments and spectroscopic quadrupole moments are well reproduced by large-scale shell–model calculations in the f5pg9 and fpg9d5 model spaces, thus establishing the dominant term in their wave function. The magnetic moment of the intruder Iπ=1/2+ isomer in 79Zn is reproduced only if the νs1/2 orbital is added to the valence space, as realized in the recently developed PFSDG-U interaction. The spin and moments of the low-lying isomeric state in 73Zn suggest a strong onset of deformation at N=43, while the progression towards 79Zn points to the stability of the Z=28 and N=50 shell gaps, supporting the magicity of 78Ni. © 2017 The Author(s)
BibTeX:
@article{Wraith2017,
  author = {Wraith, C. and Yang, X.F. and Xie, L. and Babcock, C. and Bieroń, J. and Billowes, J. and Bissell, M.L. and Blaum, K. and Cheal, B. and Filippin, L. and Garcia Ruiz, R.F. and Gins, W. and Grob, L.K. and Gaigalas, G. and Godefroid, M. and Gorges, C. and Heylen, H. and Honma, M. and Jönsson, P. and Kaufmann, S. and Kowalska, M. and Krämer, J. and Malbrunot-Ettenauer, S. and Neugart, R. and Neyens, G. and Nörtershäuser, W. and Nowacki, F. and Otsuka, T. and Papuga, J. and Sánchez, R. and Tsunoda, Y. and Yordanov, D.T.},
  title = {Evolution of nuclear structure in neutron-rich odd-Zn isotopes and isomers},
  journal = {Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics},
  year = {2017},
  volume = {771},
  pages = {385 – 391},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1016/j.physletb.2017.05.085}
}
Zhang X, Wu Y, Liu X, Reis S, Jin J, Dragosits U, VanDamme M, Clarisse L, Whitburn S, Coheur P-F and Gu B (2017), "Ammonia emissions may be substantially underestimated in China", Environmental Science and Technology. Vol. 51(21), pp. 12089 – 12096.
Abstract: China is a global hotspot of atmospheric ammonia (NH3) emissions and, as a consequence, very high nitrogen (N) deposition levels are documented. However, previous estimates of total NH3 emissions in China were much lower than inference from observed deposition values would suggest, highlighting the need for further investigation. Here, we reevaluated NH3 emissions based on a mass balance approach, validated by N deposition monitoring and satellite observations, for China for the period of 2000 to 2015. Total NH3 emissions in China increased from 12.1 ± 0.8 Tg N yr-1 in 2000 to 15.6 ± 0.9 Tg N yr-1 in 2015 at an annual rate of 1.9%, which is approximately 40% higher than existing studies suggested. This difference is mainly due to more emission sources now having been included and NH3 emission rates from mineral fertilizer application and livestock having been underestimated previously. Our estimated NH3 emission levels are consistent with the measured deposition of NHx (including NH4 + and NH3) on land (11-14 Tg N yr-1) and the substantial increases in NH3 concentrations observed by satellite measurements over China. These findings substantially improve our understanding on NH3 emissions, implying that future air pollution control strategies have to consider the potentials of reducing NH3 emission in China. © 2017 American Chemical Society.
BibTeX:
@article{Zhang2017,
  author = {Zhang, Xiuming and Wu, Yiyun and Liu, Xuejun and Reis, Stefan and Jin, Jiaxin and Dragosits, Ulrike and VanDamme, Martin and Clarisse, Lieven and Whitburn, Simon and Coheur, Pierre-François and Gu, Baojing},
  title = {Ammonia emissions may be substantially underestimated in China},
  journal = {Environmental Science and Technology},
  year = {2017},
  volume = {51},
  number = {21},
  pages = {12089 – 12096},
  note = {All Open Access, Green Open Access},
  doi = {10.1021/acs.est.7b02171}
}
Alkadrou A, Bourgeois M-T, Rotger M, Boudon V and VanderAuwera J (2016), "Global frequency and intensity analysis of the ν10/ν7/ν4/ν12 band system of 12C2H4 at 10 μm using the D2h Top Data System", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 182, pp. 158 – 171.
Abstract: A global frequency and intensity analysis of the infrared tetrad of 12C2H4 located in the 600-1500cm-1 region was carried out using the tensorial formalism developed in Dijon for X2Y4 asymmetric-top molecules. It relied on spectroscopic information available in the literature and retrieved from high-resolution Fourier transform infrared spectra recorded in Brussels in the frame of either the present or previous work. In particular, 645 and 131 line intensities have been respectively measured for the weak ν10 and ν4 bands. Including the Coriolis interactions affecting the upper vibrational levels 101, 71, 41 and 121, a total of 10 757 line positions and 1645 line intensities have been assigned and fitted with global root mean square deviations of 2.6×10-4cm-1 and 2.5%, respectively. Relying on the results of the present work and available in the literature, a list of parameters for 65 776 lines in the ν10, ν7, ν4 and ν12 bands of 12C2H4 was generated. To the best of our knowledge, this is the first time that a global intensity analysis is carried out in this range of the ethylene spectrum. © 2016 Elsevier Ltd.
BibTeX:
@article{Alkadrou2016,
  author = {Alkadrou, A. and Bourgeois, M.-T. and Rotger, M. and Boudon, V. and VanderAuwera, J.},
  title = {Global frequency and intensity analysis of the ν10/ν7/ν4/ν12 band system of 12C2H4 at 10 μm using the D2h Top Data System},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2016},
  volume = {182},
  pages = {158 – 171},
  doi = {10.1016/j.jqsrt.2016.05.024}
}
Amyay B, Fayt A, Herman M and VanderAuwera J (2016), "Vibration-rotation spectroscopic database on acetylene, X1Σg+ (12C2H2)", Journal of Physical and Chemical Reference Data. Vol. 45(2)
Abstract: A complete set of calculated vibration-rotation energies of 12C2H2 (X1Σg+) is provided for all vibrational states up to 13 000 cm-1 and some at higher energies, with rotational (J) and vibrational angular momentum (l) quantum numbers such that 0 ≤ J ≤ 100 and 0 ≤ |l| ≤ 20, respectively. The calculation is performed using a global effective Hamiltonian and related spectroscopic constants from the literature [B. Amyay et al., J. Mol. Spectrosc. 267, 80 (2011)], based on the polyad model. The numerical values of all related polyad matrix elements are also provided. The model and equations for the Hamiltonian matrix elements are gathered. The experimental acetylene database used for determining the parameters is listed. © 2016 AIP Publishing LLC for the National Institute of Standards and Technology.
BibTeX:
@article{Amyay2016a,
  author = {Amyay, B. and Fayt, A. and Herman, M. and VanderAuwera, J.},
  title = {Vibration-rotation spectroscopic database on acetylene, X1Σg+ (12C2H2)},
  journal = {Journal of Physical and Chemical Reference Data},
  year = {2016},
  volume = {45},
  number = {2},
  doi = {10.1063/1.4947297}
}
Amyay B, Louviot M, Pirali O, Georges R, VanderAuwera J and Boudon V (2016), "Global analysis of the high temperature infrared emission spectrum of 12CH4 in the dyad (ν 2/ ν 4) region", Journal of Chemical Physics. Vol. 144(2)
Abstract: We report new assignments of vibration-rotation line positions of methane (12CH4) in the so-called dyad (ν2/ν4) region (1100-1500 cm-1), and the resulting update of the vibration-rotation effective model of methane, previously reported by Nikitin et al. [Phys. Chem. Chem. Phys. 15, 10071 (2013)], up to and including the tetradecad. High resolution (0.01 cm-1) emission spectra of methane have been recorded up to about 1400 K using the high-enthalpy source developed at Institut de Physique de Rennes associated with the Fourier transform spectrometer of the SOLEIL synchrotron facility (AILES beamline). Analysis of these spectra allowed extending rotational assignments in the well-known cold band (dyad-ground state (GS)) and related hot bands in the pentad-dyad system (3000 cm-1) up to Jmax = 30 and 29, respectively. In addition, 8512 new transitions belonging to the octad-pentad (up to J = 28) and tetradecad-octad (up to J = 21) hot band systems were successfully identified. As a result, the MeCaSDa database of methane was significantly improved. The line positions assigned in this work, together with the information available in the literature, were fitted using 1096 effective parameters with a dimensionless standard deviation σ = 2.09. The root mean square deviations dRMS are 3.60 × 10-3 cm-1 for dyad-GS cold band, 4.47 ×10-3 cm-1 for the pentad-dyad, 5.43 × 10-3 cm-1 for the octad-pentad, and 4.70 × 10-3 cm-1 for the tetradecad-octad hot bands. The resulting new line list will contribute to improve opacity and radiative transfer models for hot atmospheres, such as those of hot-Jupiter type exoplanets. © 2016 AIP Publishing LLC.
BibTeX:
@article{Amyay2016,
  author = {Amyay, Badr and Louviot, Maud and Pirali, Olivier and Georges, Robert and VanderAuwera, Jean and Boudon, Vincent},
  title = {Global analysis of the high temperature infrared emission spectrum of 12CH4 in the dyad (ν 2/ ν 4) region},
  journal = {Journal of Chemical Physics},
  year = {2016},
  volume = {144},
  number = {2},
  doi = {10.1063/1.4939521}
}
Balis D, Koukouli M-E, Siomos N, Dimopoulos S, Mona L, Pappalardo G, Marenco F, Clarisse L, J Ventress L, Carboni E, G Grainger R, Wang P, Tilstra G, Van Der A R, Theys N and Zehner C (2016), "Validation of ash optical depth and layer height retrieved from passive satellite sensors using EARLINET and airborne lidar data: the case of the Eyjafjallajökull eruption", Atmospheric Chemistry and Physics. Vol. 16(9), pp. 5705 – 5720.
Abstract: The vulnerability of the European airspace to volcanic eruptions was brought to the attention of the public and the scientific community by the 2010 eruptions of the Icelandic volcano Eyjafjallajökull. As a consequence of this event, ash concentration thresholds replaced the ĝ zero tolerance to ashĝ€ rule, drastically changing the requirements on satellite ash retrievals. In response to that, the ESA funded several projects aiming at creating an optimal end-to-end system for volcanic ash plume monitoring and prediction. Two of them, namely the SACS-2 and SMASH projects, developed and improved dedicated satellite-derived ash plume and sulfur dioxide level assessments. The validation of volcanic ash levels and height extracted from the GOME-2 and IASI instruments on board the MetOp-A satellite is presented in this work. EARLINET lidar measurements are compared to different satellite retrievals for two eruptive episodes in April and May 2010. Comparisons were also made between satellite retrievals and aircraft lidar data obtained with the UK's BAe-146-301 Atmospheric Research Aircraft (managed by the Facility for Airborne Atmospheric Measurements, FAAM) over the United Kingdom and the surrounding regions. The validation results are promising for most satellite products and are within the estimated uncertainties of each of the comparative data sets, but more collocation scenes would be desirable to perform a comprehensive statistical analysis. The satellite estimates and the validation data sets are better correlated for high ash optical depth values, with correlation coefficients greater than 0.8. The IASI retrievals show a better agreement concerning the ash optical depth and ash layer height when compared with the ground-based and airborne lidar data. © Author(s) 2016. CC Attribution 3.0 License.
BibTeX:
@article{Balis2016a,
  author = {Balis, Dimitris and Koukouli, Maria-Elissavet and Siomos, Nikolaos and Dimopoulos, Spyridon and Mona, Lucia and Pappalardo, Gelsomina and Marenco, Franco and Clarisse, Lieven and J Ventress, Lucy and Carboni, Elisa and G Grainger, Roy and Wang, Ping and Tilstra, Gijsbert and Van Der A, Ronald and Theys, Nicolas and Zehner, Claus},
  title = {Validation of ash optical depth and layer height retrieved from passive satellite sensors using EARLINET and airborne lidar data: the case of the Eyjafjallajökull eruption},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {9},
  pages = {5705 – 5720},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-5705-2016}
}
Balis D, Siomos N, Koukouli M, Clarisse L, Carboni E, Ventress L, Grainger R, Mona L and Pappalardo G (2016), "Validation of ASH Optical Depth and Layer Height from IASI using Earlinet Lidar Data", EPJ Web of Conferences. Vol. 119
Abstract: The 2010 eruptions of the Icelandic volcano Eyjafjallajokull attracted the attention of the public and the scientific community to the vulnerability of the European airspace to volcanic eruptions. The European Space Agency project "Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation Hazards", called for the creation of an optimal End-to-End System for Volcanic Ash Plume Monitoring and Prediction. This system is based on improved and dedicated satellite-derived ash plume and sulphur dioxide level assessments, as well as an extensive validation, using among others ground-based measurements (Koukouli et al., 2014). The validation of volcanic ash levels and height extracted from IASI/MetopA is presented in this work with emphasis on the ash plume height and ash optical depth levels. European Aerosol Research Lidar Network [EARLINET] lidar measurements are compared to different satellite estimates for two eruptive episodes. The validation results are extremely promising within the estimated uncertainties of each of the comparative datasets. © 2016 Owned by the authors, published by EDP Sciences.
BibTeX:
@conference{Balis2016,
  author = {Balis, D. and Siomos, N. and Koukouli, M. and Clarisse, L. and Carboni, E. and Ventress, L. and Grainger, R. and Mona, L. and Pappalardo, G.},
  title = {Validation of ASH Optical Depth and Layer Height from IASI using Earlinet Lidar Data},
  journal = {EPJ Web of Conferences},
  year = {2016},
  volume = {119},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1051/epjconf/201611907006}
}
Bauduin S, Clarisse L, Hadji-Lazaro J, Theys N, Clerbaux C and Coheur P-F (2016), "Retrieval of near-surface sulfur dioxide (SO2) concentrations at a global scale using IASI satellite observations", Atmospheric Measurement Techniques. Vol. 9(2), pp. 721 – 740.
Abstract: SO2 from volcanic eruptions is now operationally monitored from space in both the ultraviolet (UV) and thermal infrared (TIR) spectral range, but anthropogenic SO2 has almost solely been measured from UV sounders. Indeed, TIR instruments are well known to have a poor sensitivity to the planetary boundary layer (PBL), due to generally low thermal contrast (TC) between the ground and the air above it. Recent studies have demonstrated the capability of the Infrared Atmospheric Sounding Interferometer (IASI) to measure near-surface SO2 locally, for specific atmospheric conditions. In this work, we develop a retrieval method allowing the inference of SO2 near-surface concentrations from IASI measurements at a global scale. This method consists of two steps. Both are based on the computation of radiance indexes representing the strength of the SO2 ν3 band in IASI spectra. The first step allows the peak altitude of SO2 to be retrieved and near-surface SO2 to be selected. In the second step, 0-4 km columns of SO2 are inferred using a look-up table (LUT) approach. Using this new retrieval method, we obtain the first global distribution of near-surface SO2 from IASI-A, and identify the dominant anthropogenic hotspot sources and volcanic degassing. The 7-year daily time evolution of SO2 columns above two industrial source areas (Beijing in China and Sar Cheshmeh in Iran) is investigated and correlated to the seasonal variations of the parameters that drive the IASI sensitivity to the PBL composition. Apart from TC, we show that humidity is the most important parameter which determines IR sensitivity to nearsurface SO2 in the ν3 band. As IASI provides global measurements twice daily, the differences between the retrieved columns for the morning and evening orbits are investigated. This paper finally presents a first intercomparison of the measured 0-4 km columns with an independent iterative retrieval method and with observations of the Ozone Monitoring Instrument (OMI). © Author(s) 2016.
BibTeX:
@article{Bauduin2016,
  author = {Bauduin, Sophie and Clarisse, Lieven and Hadji-Lazaro, Juliette and Theys, Nicolas and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {Retrieval of near-surface sulfur dioxide (SO2) concentrations at a global scale using IASI satellite observations},
  journal = {Atmospheric Measurement Techniques},
  year = {2016},
  volume = {9},
  number = {2},
  pages = {721 – 740},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-9-721-2016}
}
Bissell M, Carette T, Flanagan K, Vingerhoets P, Billowes J, Blaum K, Cheal B, Fritzsche S, Godefroid M, Kowalska M, Krämer J, Neugart R, Neyens G, Nörtershäuser W and Yordanov D (2016), "Cu charge radii reveal a weak sub-shell effect at N=40", Physical Review C. Vol. 93(6)
Abstract: Collinear laser spectroscopy on Cu58-75 isotopes was performed at the CERN-ISOLDE radioactive ion beam facility. In this paper we report on the isotope shifts obtained from these measurements. State-of-the-art atomic physics calculations have been undertaken in order to determine the changes in mean-square charge radii δ(r2)A,A′ from the observed isotope shifts. A local minimum is observed in these radii differences at N=40, providing evidence for a weak N=40 sub-shell effect. However, comparison of δ(r2)A,A′ with a droplet model prediction including static deformation deduced from the spectroscopic quadrupole moments, points to the persistence of correlations at N=40. © 2016 authors. Published by the American Physical Society.
BibTeX:
@article{Bissell2016,
  author = {Bissell, M.L. and Carette, T. and Flanagan, K.T. and Vingerhoets, P. and Billowes, J. and Blaum, K. and Cheal, B. and Fritzsche, S. and Godefroid, M. and Kowalska, M. and Krämer, J. and Neugart, R. and Neyens, G. and Nörtershäuser, W. and Yordanov, D.T.},
  title = {Cu charge radii reveal a weak sub-shell effect at N=40},
  journal = {Physical Review C},
  year = {2016},
  volume = {93},
  number = {6},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1103/PhysRevC.93.064318}
}
Boichu M, Chiapello I, Brogniez C, Péré J-C, Thieuleux F, Torres B, Blarel L, Mortier A, Podvin T, Goloub P, Söhne N, Clarisse L, Bauduin S, Hendrick F, Theys N, vanRoozendael M and Tanré D (2016), "Current challenges in modelling far-range air pollution induced by the 2014-2015 Bároarbunga fissure eruption (Iceland)", Atmospheric Chemistry and Physics. Vol. 16(17), pp. 10831 – 10845.
Abstract: The 2014-2015 Holuhraun lava-flood eruption of Bároarbunga volcano (Iceland) emitted prodigious amounts of sulfur dioxide into the atmosphere. This eruption caused a large-scale episode of air pollution throughout Western Europe in September 2014, the first event of this magnitude recorded in the modern era. We gathered chemistry-transport simulations and a wealth of complementary observations from satellite sensors (OMI, IASI), ground-based remote sensing (lidar, sunphotometry, differential optical absorption spectroscopy) and ground-level air quality monitoring networks to characterize both the spatial-temporal distributions of volcanic SO2 and sulfate aerosols as well as the dynamics of the planetary boundary layer. Time variations of dynamical and microphysical properties of sulfate aerosols in the aged low-tropospheric volcanic cloud, including loading, vertical distribution, size distribution and single scattering albedo, are provided. Retrospective chemistry-transport simulations at low horizontal resolution (25 km × 25 km) capture the correct temporal dynamics of this far-range air pollution event but fail to reproduce the correct magnitude of SO2 concentration at ground-level. Simulations at higher spatial resolution, relying on two nested domains with finest resolution of 7.3 km × 7.3 km, improve substantially the far-range vertical distribution of the volcanic cloud and subsequently the description of ground-level SO2 concentrations. However, remaining discrepancies between model and observations are shown to result from an inaccurate representation of the planetary boundary layer (PBL) dynamics. Comparison with lidar observations points out a systematic under-estimation of the PBL height by the model, whichever the PBL parameterization scheme. Such a shortcoming impedes the capture of the overlying Bároarbunga cloud into the PBL at the right time and in sufficient quantities. This study therefore demonstrates the key role played by the PBL dynamics in accurately modelling large-scale volcanogenic air pollution. © 2016 Author(s).
BibTeX:
@article{Boichu2016,
  author = {Boichu, Marie and Chiapello, Isabelle and Brogniez, Colette and Péré, Jean-Christophe and Thieuleux, Francois and Torres, Benjamin and Blarel, Luc and Mortier, Augustin and Podvin, Thierry and Goloub, Philippe and Söhne, Nathalie and Clarisse, Lieven and Bauduin, Sophie and Hendrick, François and Theys, Nicolas and vanRoozendael, Michel and Tanré, Didier},
  title = {Current challenges in modelling far-range air pollution induced by the 2014-2015 Bároarbunga fissure eruption (Iceland)},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {17},
  pages = {10831 – 10845},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-10831-2016}
}
Boynard A, Hurtmans D, Koukouli ME, Goutail F, Bureau J, Safieddine S, Lerot C, Hadji-Lazaro J, Wespes C, Pommereau J-P, Pazmino A, Zyrichidou I, Balis D, Barbe A, Mikhailenko SN, Loyola D, Valks P, vanRoozendael M, Coheur P-F and Clerbaux C (2016), "Seven years of IASI ozone retrievals from FORLI: Validation with independent total column and vertical profile measurements", Atmospheric Measurement Techniques. Vol. 9(9), pp. 4327 – 4353.
Abstract: This paper presents an extensive intercomparison and validation for the ozone (O3) product measured by the two Infrared Atmospheric Sounding Interferometers (IASIs) launched on board the MetOp-A and MetOp-B satellites in 2006 and in 2012 respectively. IASI O3 total columns and vertical profiles obtained from Fast Optimal Retrievals on Layers for IASI (FORLI) v20140922 software (running up until recently) are validated against independent observations during the period 2008-2014 on a global scale. On average for the period 2013-2014, IASI-A and IASI-B total ozone columns (TOCs) retrieved using FORLI are consistent, with IASI-B providing slightly lower values with a global difference of only 0.2±0.8%. The comparison between IASI-A and IASI-B O3 vertical profiles shows differences within ±2% over the entire altitude range. Global validation results for 7 years of IASI TOCs from FORLI against the Global Ozone Monitoring Experiment-2 (GOME-2) launched on board MetOp-A and Brewer-Dobson data show that, on average, IASI overestimates the ultraviolet (UV) data by 5-6% with the largest differences found in the southern high latitudes. The comparison with UV-visible SAOZ (Système d'Analyse par Observation Zénithale) measurements shows a mean bias between IASI and SAOZ TOCs of 2-4% in the midlatitudes and tropics and 7% at the polar circle. Part of the discrepancies found at high latitudes can be attributed to the limited information content in the observations due to low brightness temperatures. The comparison with ozonesonde vertical profiles (limited to 30km) shows that on average IASI with FORLI processing underestimates O3 by ∼ 5-15% in the troposphere while it overestimates O3 by ∼ 10-40% in the stratosphere, depending on the latitude. The largest relative differences are found in the tropical tropopause region; this can be explained by the low O3 amounts leading to large relative errors. In this study, we also evaluate an updated version of FORLI-O3 retrieval software (v20151001), using look-up tables recalculated to cover a larger spectral range using the latest HITRAN spectroscopic database (HITRAN 2012) and implementing numerical corrections. The assessment of the new O3 product with the same set of observations as that used for the validation exercise shows a correction of ∼ 4% for the TOC positive bias when compared to the UV ground-based and satellite observations, bringing the overall global comparison to ∼ 1-2% on average. This improvement is mainly associated with a decrease in the retrieved O3 concentration in the middle stratosphere (above 30hPa/25km) as shown by the comparison with ozonesonde data. © Author(s) 2016.
BibTeX:
@article{Boynard2016,
  author = {Boynard, Anne and Hurtmans, Daniel and Koukouli, Mariliza E. and Goutail, Florence and Bureau, Jérôme and Safieddine, Sarah and Lerot, Christophe and Hadji-Lazaro, Juliette and Wespes, Catherine and Pommereau, Jean-Pierre and Pazmino, Andrea and Zyrichidou, Irene and Balis, Dimitris and Barbe, Alain and Mikhailenko, Semen N. and Loyola, Diego and Valks, Pieter and vanRoozendael, Michel and Coheur, Pierre-François and Clerbaux, Cathy},
  title = {Seven years of IASI ozone retrievals from FORLI: Validation with independent total column and vertical profile measurements},
  journal = {Atmospheric Measurement Techniques},
  year = {2016},
  volume = {9},
  number = {9},
  pages = {4327 – 4353},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-9-4327-2016}
}
Carn S, Clarisse L and Prata A (2016), "Multi-decadal satellite measurements of global volcanic degassing", Journal of Volcanology and Geothermal Research. Vol. 311, pp. 99 – 134.
Abstract: Satellite instruments have been providing measurements of global volcanic emissions of sulfur dioxide (SO2) since 1978, based on observations in the ultraviolet (UV), infrared (IR) and microwave spectral bands. We review recent advances in satellite remote sensing of volcanic gases, focusing on increased instrument sensitivity to tropospheric SO2 emissions and techniques to determine volcanic plume altitude. A synthesis of  36 years of global UV, IR and microwave satellite measurements yields an updated assessment of the volcanic SO2 flux to the upper troposphere and lower stratosphere (UTLS) between 1978 and 2014 ( 1-Tg/yr). The present availability of multiple UV and IR satellite SO2 products provides increased confidence in calculated SO2 loadings for many eruptions. We examine the temporal and latitudinal distribution of volcanic SO2 emissions and reassess the relationship between eruptive SO2 discharge and eruption magnitude, finding a first-order correlation between SO2 emission and volcanic explosivity index (VEI), but with significant scatter. Based on the observed SO2-VEI relation, we estimate the fraction of eruptive SO2 emissions released by the smallest eruptions ( 0.48 Tg/yr), which is not recorded by satellite observations. A detailed breakdown of the sources of measured SO2 emissions reveals intuitively expected correlations between eruption frequency, SO2 loading and volcanic degassing style. We discuss new constraints on e-folding times for SO2 removal in volcanic plumes, and highlight recent measurements of volcanic hydrogen chloride (HCl) injections into the UTLS. An analysis of passive volcanic emissions of SO2 detected in Ozone Monitoring Instrument (OMI) SO2 data since 2004 provides new insight into the location and stability of the dominant sources of volcanic SO2 over the past decade. Since volcanic SO2 emissions constitute a random, highly variable perturbation to the atmosphere-climate system, continued monitoring of volcanic SO2 emissions from space by multiple UV and IR instruments to extend the current multi-decadal record is essential, and near-global, geostationary measurements of SO2 may be available by the end of the current decade. © 2016 The Authors.
BibTeX:
@article{Carn2016,
  author = {Carn, S.A. and Clarisse, L. and Prata, A.J.},
  title = {Multi-decadal satellite measurements of global volcanic degassing},
  journal = {Journal of Volcanology and Geothermal Research},
  year = {2016},
  volume = {311},
  pages = {99 – 134},
  note = {All Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.jvolgeores.2016.01.002}
}
Cessateur G, De Keyser J, Maggiolo R, Rubin M, Gronoff G, Gibbons A, Jehin E, Dhooghe F, Gunell H, Vaeck N and Loreau J (2016), "2D photochemical model for forbidden oxygen line emission for comet 1P/Halley", Monthly Notices of the Royal Astronomical Society. Vol. 462, pp. S116 – S123.
Abstract: We present here a 2D model of photochemistry for computing the production and loss mechanisms of the O(1S) and O(1D) states, which are responsible for the emission lines at 577.7, 630, and 636.4 nm, in case of the comet 1P/Halley. The presence of O2 within cometary atmospheres, measured by the in situ Rosetta and Giotto missions, necessitates a revision of the usual photochemical models. Indeed, the photodissociation of molecular oxygen also leads to a significant production of oxygen in excited electronic states. In order to correctly model the solar ultraviolet (UV) flux absorption, we consider here a 2D configuration. While the green to red-doublet ratio is not affected by the solar UV flux absorption, estimates of the red-doublet and green lines emissions are, however, overestimated by a factor of 2 in the 1D model compared to the 2D model. Considering a spherical symmetry, emission maps can be deduced from the 2D model in order to be directly compared to ground and/or in situ observations. © 2017 The Authors.
BibTeX:
@article{Cessateur2016,
  author = {Cessateur, G. and De Keyser, J. and Maggiolo, R. and Rubin, M. and Gronoff, G. and Gibbons, A. and Jehin, E. and Dhooghe, F. and Gunell, H. and Vaeck, N. and Loreau, J.},
  title = {2D photochemical model for forbidden oxygen line emission for comet 1P/Halley},
  journal = {Monthly Notices of the Royal Astronomical Society},
  year = {2016},
  volume = {462},
  pages = {S116 – S123},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1093/mnras/stw2150}
}
Cessateur G, Keyser JD, Maggiolo R, Gibbons A, Gronoff G, Gunell H, Dhooghe F, Loreau J, Vaeck N, Altwegg K, Bieler A, Briois C, Calmonte U, Combi M, Fiethe B, Fuselier S, Gombosi T, Hässig M, Le Roy L, Neefs E, Rubin M and Sémon T (2016), "Photochemistry of forbidden oxygen lines in the inner coma of 67P/Churyumov-Gerasimenko", Journal of Geophysical Research: Space Physics. Vol. 121(1), pp. 804 – 816.
Abstract: Observations of the green and red-doublet emission lines have previously been realized for several comets. We present here a chemistry-emission coupled model to study the production and loss mechanisms of the O(1S) and O(1D) states, which are responsible for the emission lines of interest for comet 67P/Churyumov-Gerasimenko. The recent discovery of O2 in significant abundance relative to water 3.80 ± 0.85 within the coma of 67P has been taken into consideration for the first time in such models. We evaluate the effect of the presence of O2 on the green to red-doublet emission intensity ratio, which is traditionally used to assess the CO2 abundance within cometary atmospheres. Model simulations, solving the continuity equation with transport, show that not taking O2 into account leads to an underestimation of the CO2 abundance within 67P, with a relative error of about 25%. This strongly suggests that the green to red-doublet emission intensity ratio alone is not a proper tool for determining the CO2 abundance, as previously suggested. Indeed, there is no compelling reason why O2 would not be a common cometary volatile, making revision of earlier assessments regarding the CO2 abundance in cometary atmospheres necessary. The large uncertainties of the CO2 photodissociation cross section imply that more studies are required in order to better constrain the O(1S) and O(1D) production through this mechanism. Space weather phenomena, such as powerful solar flares, could be used as tools for doing so, providing additional information on a good estimation of the O2 abundance within cometary atmospheres. ©2016. The Authors.
BibTeX:
@article{Cessateur2016a,
  author = {Cessateur, G. and Keyser, J. De and Maggiolo, R. and Gibbons, A. and Gronoff, G. and Gunell, H. and Dhooghe, F. and Loreau, J. and Vaeck, N. and Altwegg, K. and Bieler, A. and Briois, C. and Calmonte, U. and Combi, M.R. and Fiethe, B. and Fuselier, S.A. and Gombosi, T.I. and Hässig, M. and Le Roy, L. and Neefs, E. and Rubin, M. and Sémon, T.},
  title = {Photochemistry of forbidden oxygen lines in the inner coma of 67P/Churyumov-Gerasimenko},
  journal = {Journal of Geophysical Research: Space Physics},
  year = {2016},
  volume = {121},
  number = {1},
  pages = {804 – 816},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1002/2015JA022013}
}
Clarisse L and Prata F (2016), "Infrared Sounding of Volcanic Ash", Volcanic Ash: Hazard Observation. , pp. 189 – 215.
Abstract: In the first part of this chapter, the spectral content of the thermal infrared spectral region for the sounding of volcanic eruptions is explored through analysis of simulated and real observed spectra. Next, we review the literature on algorithms for the identification and retrieval of volcanic ash, both from broadband and hyperspectral infrared measurements. The final part of this chapter treats the topic of validation of satellite-based ash retrievals. © 2016 Elsevier Ltd. All rights reserved.
BibTeX:
@book{Clarisse2016,
  author = {Clarisse, L. and Prata, F.},
  title = {Infrared Sounding of Volcanic Ash},
  journal = {Volcanic Ash: Hazard Observation},
  year = {2016},
  pages = {189 – 215},
  doi = {10.1016/B978-0-08-100405-0.00017-3}
}
Dammers E, Palm M, VanDamme M, Vigouroux C, Smale D, Conway S, Toon GC, Jones N, Nussbaumer E, Warneke T, Petri C, Clarisse L, Clerbaux C, Hermans C, Lutsch E, Strong K, Hannigan JW, Nakajima H, Morino I, Herrera B, Stremme W, Grutter M, Schaap M, Kruit RJW, Notholt J, Coheur P-F and Erisman JW (2016), "An evaluation of IASI-NH3 with ground-based Fourier transform infrared spectroscopy measurements", Atmospheric Chemistry and Physics. Vol. 16(16), pp. 10351 – 10368.
Abstract: Global distributions of atmospheric ammonia (NH3) measured with satellite instruments such as the Infrared Atmospheric Sounding Interferometer (IASI) contain valuable information on NH3 concentrations and variability in regions not yet covered by ground-based instruments. Due to their large spatial coverage and (bi-)daily overpasses, the satellite observations have the potential to increase our knowledge of the distribution of NH3 emissions and associated seasonal cycles. However the observations remain poorly validated, with only a handful of available studies often using only surface measurements without any vertical information. In this study, we present the first validation of the IASI-NH3 product using ground-based Fourier transform infrared spectroscopy (FTIR) observations. Using a recently developed consistent retrieval strategy, NH3 concentration profiles have been retrieved using observations from nine Network for the Detection of Atmospheric Composition Change (NDACC) stations around the world between 2008 and 2015. We demonstrate the importance of strict spatio-temporal collocation criteria for the comparison. Large differences in the regression results are observed for changing intervals of spatial criteria, mostly due to terrain characteristics and the short lifetime of NH3 in the atmosphere. The seasonal variations of both datasets are consistent for most sites. Correlations are found to be high at sites in areas with considerable NH3 levels, whereas correlations are lower at sites with low atmospheric NH3 levels close to the detection limit of the IASI instrument. A combination of the observations from all sites (Nobs Combining double low line 547) give a mean relative difference of ĝ'32.4ĝ€±ĝ€(56.3)ĝ€%, a correlation r of 0.8 with a slope of 0.73. These results give an improved estimate of the IASI-NH3 product performance compared to the previous upper-bound estimates (-50 to +100%). © Author(s) 2016.
BibTeX:
@article{Dammers2016,
  author = {Dammers, Enrico and Palm, Mathias and VanDamme, Martin and Vigouroux, Corinne and Smale, Dan and Conway, Stephanie and Toon, Geoffrey C. and Jones, Nicholas and Nussbaumer, Eric and Warneke, Thorsten and Petri, Christof and Clarisse, Lieven and Clerbaux, Cathy and Hermans, Christian and Lutsch, Erik and Strong, Kim and Hannigan, James W. and Nakajima, Hideaki and Morino, Isamu and Herrera, Beatriz and Stremme, Wolfgang and Grutter, Michel and Schaap, Martijn and Kruit, Roy J. Wichink and Notholt, Justus and Coheur, Pierre-F. and Erisman, Jan Willem},
  title = {An evaluation of IASI-NH3 with ground-based Fourier transform infrared spectroscopy measurements},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {16},
  pages = {10351 – 10368},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-10351-2016}
}
Desrier A, Romanzin C, Lamarre N, Alcaraz C, Gans B, Gauyacq D, Liévin J and Boyé-Péronne S (2016), "Experimental and ab initio characterization of HC3N+ vibronic structure. I. Synchrotron-based threshold photo-electron spectroscopy", Journal of Chemical Physics. Vol. 145(23)
Abstract: Threshold-photoionization spectroscopy of cyanoacetylene (HC3N) and its 15N isotopologue has been investigated in the vacuum-ultraviolet range with a synchrotron-based experiment allowing to record threshold-photoelectron spectrum and photoion yield over a large energy range (from 88 500 to 177 500 cm-1, i.e., from 11 to 22 eV). Adiabatic ionization energies towards the three lowest electronic states X+ 2Π, A+ Σ+2, and B+ Π2 are derived from the threshold-photoelectron spectrum. A detailed description of the vibrational structure of these states is proposed leading to the determination of the vibrational frequencies for most modes. The vibrational assignments and the discussion about the electronic structure are supported by multireference ab initio calculations (CASPT2, MRCI). Unprecedented structures are resolved and tentatively assigned in the region of the B+ X transition. Exploratory calculations highlight the complexity of the electronic landscape of the cation up to approximately 10 eV above its ground state. © 2016 Author(s).
BibTeX:
@article{Desrier2016,
  author = {Desrier, Antoine and Romanzin, Claire and Lamarre, Nicolas and Alcaraz, Christian and Gans, Bérenger and Gauyacq, Dolores and Liévin, Jacques and Boyé-Péronne, Séverine},
  title = {Experimental and ab initio characterization of HC3N+ vibronic structure. I. Synchrotron-based threshold photo-electron spectroscopy},
  journal = {Journal of Chemical Physics},
  year = {2016},
  volume = {145},
  number = {23},
  doi = {10.1063/1.4972019}
}
Filippin L, Beerwerth R, Ekman J, Fritzsche S, Godefroid M and Jönsson P (2016), "Multiconfiguration calculations of electronic isotope shift factors in Al i", Physical Review A. Vol. 94(6)
Abstract: The present work reports results from systematic multiconfiguration Dirac-Hartree-Fock calculations of electronic isotope shift factors for a set of transitions between low-lying levels of neutral aluminium. These electronic quantities together with observed isotope shifts between different pairs of isotopes provide the changes in mean-square charge radii of the atomic nuclei. Two computational approaches are adopted for the estimation of the mass- and field-shift factors. Within these approaches, different models for electron correlation are explored in a systematic way to determine a reliable computational strategy and to estimate theoretical error bars of the isotope shift factors. © 2016 American Physical Society.
BibTeX:
@article{Filippin2016a,
  author = {Filippin, Livio and Beerwerth, Randolf and Ekman, Jörgen and Fritzsche, Stephan and Godefroid, Michel and Jönsson, Per},
  title = {Multiconfiguration calculations of electronic isotope shift factors in Al i},
  journal = {Physical Review A},
  year = {2016},
  volume = {94},
  number = {6},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.94.062508}
}
Filippin L, Godefroid M and Baye D (2016), "Relativistic two-photon decay rates with the Lagrange-mesh method", Physical Review A. Vol. 93(1)
Abstract: Relativistic two-photon decay rates of the 2s1/2 and 2p1/2 states towards the 1s1/2 ground state of hydrogenic atoms are calculated by using numerically exact energies and wave functions obtained from the Dirac equation with the Lagrange-mesh method. This approach is an approximate variational method taking the form of equations on a grid because of the use of a Gauss quadrature approximation. Highly accurate values are obtained by a simple calculation involving different meshes for the initial, final, and intermediate wave functions and for the calculation of matrix elements. The accuracy of the results with a Coulomb potential is improved by several orders of magnitude in comparison with benchmark values from the literature. The general requirement of gauge invariance is also successfully tested, down to rounding errors. The method provides high accuracies for two-photon decay rates of a particle in other potentials and is applied to a hydrogen atom embedded in a Debye plasma simulated by a Yukawa potential. © 2016 American Physical Society.
BibTeX:
@article{Filippin2016,
  author = {Filippin, Livio and Godefroid, Michel and Baye, Daniel},
  title = {Relativistic two-photon decay rates with the Lagrange-mesh method},
  journal = {Physical Review A},
  year = {2016},
  volume = {93},
  number = {1},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.93.012517}
}
Filippin L, Godefroid M, Ekman J and Jönsson P (2016), "Core correlation effects in multiconfiguration calculations of isotope shifts in Mg I", Physical Review A. Vol. 93(6)
Abstract: The present work reports results from systematic multiconfiguration Dirac-Hartree-Fock calculations of isotope shifts for several well-known transitions in neutral magnesium. Relativistic normal and specific mass shift factors as well as the electronic probability density at the origin are calculated. Combining these electronic quantities with available nuclear data, energy and transition level shifts are determined for the Mg26-Mg24 pair of isotopes. Different models for electron correlation are adopted. It is shown that, although valence and core-valence models provide accurate values for the isotope shifts, the inclusion of core-core excitations in the computational strategy significantly improves the accuracy of the transition energies and normal mass shift factors. © 2016 American Physical Society.
BibTeX:
@article{Filippin2016b,
  author = {Filippin, Livio and Godefroid, Michel and Ekman, Jörgen and Jönsson, Per},
  title = {Core correlation effects in multiconfiguration calculations of isotope shifts in Mg I},
  journal = {Physical Review A},
  year = {2016},
  volume = {93},
  number = {6},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.93.062512}
}
Fischer CF, Godefroid M, Brage T, Jönsson P and Gaigalas G (2016), "Advanced multiconfiguration methods for complex atoms: I. Energies and wave functions", Journal of Physics B: Atomic, Molecular and Optical Physics. Vol. 49(18)
Abstract: Multiconfiguration wave function expansions combined with configuration interaction methods are a method of choice for complex atoms where atomic state functions are expanded in a basis of configuration state functions. Combined with a variational method such as the multiconfiguration Hartree-Fock (MCHF) or multiconfiguration Dirac-Hartree-Fock (MCDHF), the associated set of radial functions can be optimized for the levels of interest. The present review updates the variational MCHF theory to include MCDHF, describes the multireference single and double process for generating expansions and the systematic procedure of a computational scheme for monitoring convergence. It focuses on the calculations of energies and wave functions from which other atomic properties can be predicted such as transition rates, hyperfine structures and isotope shifts, for example. © 2016 IOP Publishing Ltd.
BibTeX:
@article{Fischer2016,
  author = {Fischer, Charlotte Froese and Godefroid, Michel and Brage, Tomas and Jönsson, Per and Gaigalas, Gediminas},
  title = {Advanced multiconfiguration methods for complex atoms: I. Energies and wave functions},
  journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  year = {2016},
  volume = {49},
  number = {18},
  note = {All Open Access, Green Open Access},
  doi = {10.1088/0953-4075/49/18/182004}
}
Földes T, Vanfleteren T, Rizopoulos A, Herman M, VanderAuwera J, Softley T, DiLonardo G and Fusina L (2016), "High-resolution room temperature and jet-cooled spectroscopic investigation of 15NH3 in the ν1+ν3 band region (1.51 μm)", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 179, pp. 112 – 125.
Abstract: Spectra of 99% isotopically pure 15NH3 were recorded using cavity ring-down (CRD, 6567-6639 cm-1) and Fourier transform (FT, 6350-6985 cm-1) spectroscopy under jet cooled and room temperature conditions, respectively. Measured line positions on both data sets improve on literature values, in particular by one order of magnitude for the ν1+ν3 band. A room temperature list of line positions, with approximate line intensities, is provided, much more complete and precise than presently available. Line broadening effects in the CRD spectrum allowed lines with J'''- values between 0 and 3 to be identified. Ground state combination differences were used to refine the assignments, further assisted by intensity ratios between the two data sets. Reliable values for J, K and inversion symmetry of the ground state vibrational levels, as well as further information on a/s doublets could be obtained, updating and extending literature assignments. © 2016 Elsevier Ltd.
BibTeX:
@article{Foeldes2016,
  author = {Földes, T. and Vanfleteren, T. and Rizopoulos, A. and Herman, M. and VanderAuwera, J. and Softley, T.P. and DiLonardo, G. and Fusina, L.},
  title = {High-resolution room temperature and jet-cooled spectroscopic investigation of 15NH3 in the ν1+ν3 band region (1.51 μm)},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2016},
  volume = {179},
  pages = {112 – 125},
  doi = {10.1016/j.jqsrt.2016.03.018}
}
Fortems-Cheiney A, Dufour G, Hamaoui-Laguel L, Foret G, Siour G, VanDamme M, Meleux F, Coheur P-F, Clerbaux C, Clarisse L, Favez O, Wallasch M and Beekmann M (2016), "Unaccounted variability in NH3 agricultural sources detected by IASI contributing to European spring haze episode", Geophysical Research Letters. Vol. 43(10), pp. 5475 – 5482.
Abstract: Ammonia (NH3), whose main source in the troposphere is agriculture, is an important gaseous precursor of atmospheric particulate matter (PM). We derived daily ammonia emissions using NH3 total columns measured from the Infrared Atmospheric Sounding Interferometer (IASI) on board Metop-A, at a relatively high spatial resolution (grid cell of 0.5° × 0.5°). During the European spring haze episodes of 24–31 March 2012 and 8–15 March 2014, IASI reveals NH3 total column magnitudes highlighting higher NH3 emissions over central Europe (especially over Germany, Czech Republic, and eastern France) from the ones provided by the European reference European Monitoring and Evaluation Programme inventory. These ammonia emissions exhibit in addition a large day-to-day variability, certainly due to spreading practices. The increase of NH3 emissions in the model, that reaches +300% locally, leads to an increase of both NH3 and PM2.5 surface concentrations and allows for a better comparison with independent measurements (in terms of bias, root-mean-square error, and correlation). This study suggests that there are good prospects for better quantifying NH3 emissions by atmospheric inversions. ©2016. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{FortemsCheiney2016,
  author = {Fortems-Cheiney, A. and Dufour, G. and Hamaoui-Laguel, L. and Foret, G. and Siour, G. and VanDamme, M. and Meleux, F. and Coheur, P.-F. and Clerbaux, C. and Clarisse, L. and Favez, O. and Wallasch, M. and Beekmann, M.},
  title = {Unaccounted variability in NH3 agricultural sources detected by IASI contributing to European spring haze episode},
  journal = {Geophysical Research Letters},
  year = {2016},
  volume = {43},
  number = {10},
  pages = {5475 – 5482},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1002/2016GL069361}
}
Franco B, A Marais E, Bovy B, Bader W, Lejeune B, Roland G, Servais C and Mahieu E (2016), "Diurnal cycle and multi-decadal trend of formaldehyde in the remote atmosphere near 46°N", Atmospheric Chemistry and Physics. Vol. 16(6), pp. 4171 – 4189.
Abstract: Only very few long-term records of formaldehyde (HCHO) exist that are suitable for trend analysis. Furthermore, many uncertainties remain as to its diurnal cycle, representing a large short-term variability superimposed on seasonal and inter-annual variations that should be accounted for when comparing ground-based observations to, e.g., model results. In this study, we derive a multi-decadal time series (January 1988-June 2015) of HCHO total columns from ground-based high-resolution Fourier transform infrared (FTIR) solar spectra recorded at the high-altitude station of Jungfraujoch (Swiss Alps, 46.5°N, 8.0°E, 3580ma. s. l. ), allowing for the characterization of the mid-latitudinal atmosphere for background conditions. First we investigate the HCHO diurnal variation, peaking around noontime and mainly driven by the intra-day insolation modulation and methane (CH4) oxidation. We also characterize quantitatively the diurnal cycles by adjusting a parametric model to the observations, which links the daytime to the HCHO columns according to the monthly intra-day regimes. It is then employed to scale all the individual FTIR measurements on a given daytime in order to remove the effect of the intra-day modulation for improving the trend determination and the comparison with HCHO columns simulated by the state-of-the-art GEOS-Chem v9-02 chemical transport model. Such a parametric model will be useful to scale the Jungfraujoch HCHO columns on satellite overpass times in the framework of future calibration/validation efforts of space-borne sensors. GEOS-Chem sensitivity tests suggest then that the seasonal and inter-annual HCHO column variations above Jungfraujoch are predominantly led by the atmospheric CH4 oxidation, with a maximum contribution of 25% from the anthropogenic non-methane volatile organic compound precursors during wintertime. Finally, trend analysis of the so-scaled 27-year FTIR time series reveals a long-term evolution of the HCHO columns in the remote troposphere to be related to the atmospheric CH4 fluctuations and the short-term OH variability: +2.9%year-1 between 1988 and 1995, -3.7%year-1 over 1996-2002 and +0.8%year-1 from 2003 onwards. © Author(s) 2016.
BibTeX:
@article{Franco2016a,
  author = {Franco, Bruno and A Marais, Eloise and Bovy, Benoît and Bader, Whitney and Lejeune, Bernard and Roland, Ginette and Servais, Christian and Mahieu, Emmanuel},
  title = {Diurnal cycle and multi-decadal trend of formaldehyde in the remote atmosphere near 46°N},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {6},
  pages = {4171 – 4189},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-4171-2016}
}
Franco B, Mahieu E, Emmons L, Tzompa-Sosa Z, Fischer E, Sudo K, Bovy B, Conway S, Griffin D, Hannigan J, Strong K and Walker K (2016), "Evaluating ethane and methane emissions associated with the development of oil and natural gas extraction in North America", Environmental Research Letters. Vol. 11(4)
Abstract: Sharp rises in the atmospheric abundance of ethane (C2H6) have been detected from 2009 onwards in the Northern Hemisphere as a result of the unprecedented growth in the exploitation of shale gas and tight oil reservoirs in North America. Using time series of C2H6 total columns derived from ground-based Fourier transform infrared (FTIR) observations made at five selected Network for the Detection of Atmospheric Composition Change sites, we characterize the recent C2H6 evolution and determine growth rates of ∼5% yr-1 at mid-latitudes and of ∼3% yr-1 at remote sites. Results from CAM-chem simulations with the Hemispheric Transport of Air Pollutants, Phase II bottom-up inventory for anthropogenic emissions are found to greatly underestimate the current C2H6 abundances. Doubling global emissions is required to reconcile the simulations and the observations prior to 2009. We further estimate that North American anthropogenic C2H6 emissions have increased from 1.6 Tg yr-1 in 2008 to 2.8 Tg yr-1 in 2014, i.e. by 75% over these six years. We also completed a second simulation with new top-down emissions of C2H6 from North American oil and gas activities, biofuel consumption and biomass burning, inferred from space-borne observations of methane (CH4) from Greenhouse Gases Observing SATellite. In this simulation, GEOS-Chem is able to reproduce FTIR measurements at the mid-latitudinal sites, underscoring the impact of the North American oil and gas development on the current C2H6 abundance. Finally we estimate that the North American oil and gas emissions of CH4, a major greenhouse gas, grew from 20 to 35 Tg yr-1 over the period 2008-2014, in association with the recent C2H6 rise. © 2016 IOP Publishing Ltd.
BibTeX:
@article{Franco2016,
  author = {Franco, B. and Mahieu, E. and Emmons, L.K. and Tzompa-Sosa, Z.A. and Fischer, E.V. and Sudo, K. and Bovy, B. and Conway, S. and Griffin, D. and Hannigan, J.W. and Strong, K. and Walker, K.A.},
  title = {Evaluating ethane and methane emissions associated with the development of oil and natural gas extraction in North America},
  journal = {Environmental Research Letters},
  year = {2016},
  volume = {11},
  number = {4},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1088/1748-9326/11/4/044010}
}
Gans B, Lamarre N, Broquier M, Liévin J and Boyé-Péronne S (2016), "Experimental and ab initio characterization of HC3N+ vibronic structure. II. High-resolution VUV PFI-ZEKE spectroscopy", Journal of Chemical Physics. Vol. 145(23)
Abstract: Vacuum-ultraviolet pulsed-field-ionization zero-kinetic-energy photoelectron spectra of X+Π2←XΣ+1 and B+Π2←XΣ+1 transitions of the HC314N and HC315N isotopologues of cyanoacetylene have been recorded. The resolution of the photoelectron spectra allowed us to resolve the vibrational structures and the spin-orbit splittings in the cation. Accurate values of the adiabatic ionization potentials of the two isotopologues (EI/hc(HC314N)=93 909(2) cm-1 and EI/hc(HC315N)=93 912(2) cm-1), the vibrational frequencies of the ν2, ν6, and ν7 vibrational modes, and the spin-orbit coupling constant (ASO = -44(2) cm-1) of the X+Π2 cationic ground state have been derived from the measurements. Using ab initio calculations, the unexpected structure of the B+Π2←XΣ+1 transition is tentatively attributed to a conical intersection between the A+ and B+ electronic states of the cation. © 2016 Author(s).
BibTeX:
@article{Gans2016,
  author = {Gans, Bérenger and Lamarre, Nicolas and Broquier, Michel and Liévin, Jacques and Boyé-Péronne, Séverine},
  title = {Experimental and ab initio characterization of HC3N+ vibronic structure. II. High-resolution VUV PFI-ZEKE spectroscopy},
  journal = {Journal of Chemical Physics},
  year = {2016},
  volume = {145},
  number = {23},
  doi = {10.1063/1.4972018}
}
Hadjichrysanthou C, Cauët E, Lawrence E, Vegvari C, De Wolf F and Anderson RM (2016), "Understanding the within-host dynamics of influenza A virus: From theory to clinical implications", Journal of the Royal Society Interface. Vol. 13(119)
Abstract: Mathematical models have provided important insights into acute viral dynamics within individual patients. In this paper, we study the simplest target cell-limited models to investigate the within-host dynamics of influenza A virus infection in humans. Despite the biological simplicity of the models, we show how these can be used to understand the severity of the infection and the key attributes of possible immunotherapy and antiviral drugs for the treatment of infection at different times post infection. Through an analytic approach, we derive and estimate simple summary biological quantities that can provide novel insights into the infection dynamics and the definition of clinical endpoints. We focus on nine quantities, including the area under the viral load curve, peak viral load, the time to peak viral load and the level of cell death due to infection. Using Markov chain Monte Carlo methods, we fitted the models to data collected from 12 untreated volunteers who participated in two clinical studies that tested the antiviral drugs oseltamivir and zanamivir. Based on the results, we also discuss various difficulties in deriving precise estimates of the parameters, even in the very simple models considered, when experimental data are limited to viral load measures and/or there is a limited number of viral load measurements post infection. © 2016 The Authors.
BibTeX:
@article{Hadjichrysanthou2016,
  author = {Hadjichrysanthou, Christoforos and Cauët, Emilie and Lawrence, Emma and Vegvari, Carolin and De Wolf, Frank and Anderson, Roy M.},
  title = {Understanding the within-host dynamics of influenza A virus: From theory to clinical implications},
  journal = {Journal of the Royal Society Interface},
  year = {2016},
  volume = {13},
  number = {119},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1098/rsif.2016.0289}
}
Hashemi R, Predoi-Cross A, Dudaryonok A, Lavrentieva N, Vandaele A and VanderAuwera J (2016), "CO2 pressure broadening and shift coefficients for the 2–0 band of 12C16O", Journal of Molecular Spectroscopy. Vol. 326, pp. 60 – 72.
Abstract: Fourier transform absorption spectra of the 2–0 band of 12C16O mixed with CO2 have been recorded at total pressures from 156 to 1212 hPa and at 4 different temperatures between 240 K and 283 K. CO2 pressure-induced line broadening and line shift coefficients, and the temperature dependence of the former have been measured including line mixing using a multi-spectrum non-linear least squares fitting technique. Different line shape models have been considered to take into account the Dicke narrowing or speed dependence effects. Measured line-shape parameters were compared with theoretical values, calculated for individual temperatures using a semi-empirical method and the Exponential Power Gap (EPG) law. © 2016 Elsevier Inc.
BibTeX:
@article{Hashemi2016,
  author = {Hashemi, R. and Predoi-Cross, A. and Dudaryonok, A.S. and Lavrentieva, N.N. and Vandaele, A.C. and VanderAuwera, J.},
  title = {CO2 pressure broadening and shift coefficients for the 2–0 band of 12C16O},
  journal = {Journal of Molecular Spectroscopy},
  year = {2016},
  volume = {326},
  pages = {60 – 72},
  doi = {10.1016/j.jms.2016.02.014}
}
Helmig D, Rossabi S, Hueber J, Tans P, Montzka SA, Masarie K, Thoning K, Plass-Duelmer C, Claude A, Carpenter LJ, Lewis AC, Punjabi S, Reimann S, Vollmer MK, Steinbrecher R, Hannigan JW, Emmons LK, Mahieu E, Franco B, Smale D and Pozzer A (2016), "Reversal of global atmospheric ethane and propane trends largely due to US oil and natural gas production", Nature Geoscience. Vol. 9(7), pp. 490 – 495.
Abstract: Non-methane hydrocarbons such as ethane are important precursors to tropospheric ozone and aerosols. Using data from a global surface network and atmospheric column observations we show that the steady decline in the ethane mole fraction that began in the 1970s halted between 2005 and 2010 in most of the Northern Hemisphere and has since reversed. We calculate a yearly increase in ethane emissions in the Northern Hemisphere of 0.42 (±0.19) Tg yr-1 between mid-2009 and mid-2014. The largest increases in ethane and the shorter-lived propane are seen over the central and eastern USA, with a spatial distribution that suggests North American oil and natural gas development as the primary source of increasing emissions. By including other co-emitted oil and natural gas non-methane hydrocarbons, we estimate a Northern Hemisphere total non-methane hydrocarbon yearly emission increase of 1.2 (±0.8) Tg yr-1. Atmospheric chemical transport modelling suggests that these emissions could augment summertime mean surface ozone by several nanomoles per mole near oil and natural gas production regions. Methane/ethane oil and natural gas emission ratios could suggest a significant increase in associated methane emissions; however, this increase is inconsistent with observed leak rates in production regions and changes in methane's global isotopic ratio. © 2016 Macmillan Publishers Limited.
BibTeX:
@article{Helmig2016,
  author = {Helmig, Detlev and Rossabi, Samuel and Hueber, Jacques and Tans, Pieter and Montzka, Stephen A. and Masarie, Ken and Thoning, Kirk and Plass-Duelmer, Christian and Claude, Anja and Carpenter, Lucy J. and Lewis, Alastair C. and Punjabi, Shalini and Reimann, Stefan and Vollmer, Martin K. and Steinbrecher, Rainer and Hannigan, James W. and Emmons, Louisa K. and Mahieu, Emmanuel and Franco, Bruno and Smale, Dan and Pozzer, Andrea},
  title = {Reversal of global atmospheric ethane and propane trends largely due to US oil and natural gas production},
  journal = {Nature Geoscience},
  year = {2016},
  volume = {9},
  number = {7},
  pages = {490 – 495},
  note = {All Open Access, Green Open Access},
  doi = {10.1038/ngeo2721}
}
Herman M, Földes T, Didriche K, Lauzin C and Vanfleteren T (2016), "Overtone spectroscopy of molecular complexes containing small polyatomic molecules", International Reviews in Physical Chemistry. Vol. 35(2), pp. 243 – 295.
Abstract: The literature on the high-resolution spectroscopic investigation of molecular complexes containing small polyatomic species excited in their vibrational overtones is reviewed. They turn out to be complexes containing acetylene, ammonia and water, mainly excited in their 2CH, 2NH and 2OH vibrations, respectively. The majority of results published on these systems was obtained using an instrumental set-up based on cw-cavity ring-down spectroscopy, built in the ‘Laboratoire de Chimie quantique et Photophysique’ at the ‘Université libre de Bruxelles’ (CQP/ULB) and named FANTASIO+, which is described. It allowed retrieving upper state vibrational predissociation lifetimes, which are highlighted together with more results. The sequence of experiments at CQP/ULB prior and along the line of those supporting the investigation of molecular complexes is briefly illustrated. © 2016 Informa UK Limited, trading as Taylor & Francis Group.
BibTeX:
@article{Herman2016,
  author = {Herman, M. and Földes, T. and Didriche, K. and Lauzin, C. and Vanfleteren, T.},
  title = {Overtone spectroscopy of molecular complexes containing small polyatomic molecules},
  journal = {International Reviews in Physical Chemistry},
  year = {2016},
  volume = {35},
  number = {2},
  pages = {243 – 295},
  doi = {10.1080/0144235X.2016.1171039}
}
Jacquinet-Husson N, Armante R, Scott N, Chédin A, Crépeau L, Boutammine C, Bouhdaoui A, Crevoisier C, Capelle V, Boonne C, Poulet-Crovisier N, Barbe A, Chris Benner D, Boudon V, Brown L, Buldyreva J, Campargue A, Coudert L, Devi V, Down M, Drouin B, Fayt A, Fittschen C, Flaud J-M, Gamache R, Harrison J, Hill C, Hodnebrog Ø, Hu S-M, Jacquemart D, Jolly A, Jiménez E, Lavrentieva N, Liu A-W, Lodi L, Lyulin O, Massie S, Mikhailenko S, Müller H, Naumenko O, Nikitin A, Nielsen C, Orphal J, Perevalov V, Perrin A, Polovtseva E, Predoi-Cross A, Rotger M, Ruth A, Yu S, Sung K, Tashkun S, Tennyson J, Tyuterev V, VanderAuwera J, Voronin B and Makie A (2016), "The 2015 edition of the GEISA spectroscopic database", Journal of Molecular Spectroscopy. Vol. 327, pp. 31 – 72.
Abstract: The GEISA database (Gestion et Etude des Informations Spectroscopiques Atmosphériques: Management and Study of Atmospheric Spectroscopic Information) has been developed and maintained by the ARA/ABC(t) group at LMD since 1974. GEISA is constantly evolving, taking into account the best available spectroscopic data. This paper presents the 2015 release of GEISA (GEISA-2015), which updates the last edition of 2011 and celebrates the 40th anniversary of the database. Significant updates and additions have been implemented in the three following independent databases of GEISA. The “line parameters database” contains 52 molecular species (118 isotopologues) and transitions in the spectral range from 10−6 to 35,877.031 cm−1, representing 5,067,351 entries, against 3,794,297 in GEISA-2011. Among the previously existing molecules, 20 molecular species have been updated. A new molecule (SO3) has been added. HDO, isotopologue of H2O, is now identified as an independent molecular species. Seven new isotopologues have been added to the GEISA-2015 database. The “cross section sub-database” has been enriched by the addition of 43 new molecular species in its infrared part, 4 molecules (ethane, propane, acetone, acetonitrile) are also updated; they represent 3% of the update. A new section is added, in the near-infrared spectral region, involving 7 molecular species: CH3CN, CH3I, CH3O2, H2CO, HO2, HONO, NH3. The “microphysical and optical properties of atmospheric aerosols sub-database” has been updated for the first time since 2003. It contains more than 40 species originating from NCAR and 20 from the ARIA archive of Oxford University. As for the previous versions, this new release of GEISA and associated management software facilities are implemented and freely accessible on the AERIS/ESPRI atmospheric chemistry data center website. © 2016 Elsevier Inc.
BibTeX:
@article{JacquinetHusson2016,
  author = {Jacquinet-Husson, N. and Armante, R. and Scott, N.A. and Chédin, A. and Crépeau, L. and Boutammine, C. and Bouhdaoui, A. and Crevoisier, C. and Capelle, V. and Boonne, C. and Poulet-Crovisier, N. and Barbe, A. and Chris Benner, D. and Boudon, V. and Brown, L.R. and Buldyreva, J. and Campargue, A. and Coudert, L.H. and Devi, V.M. and Down, M.J. and Drouin, B.J. and Fayt, A. and Fittschen, C. and Flaud, J.-M. and Gamache, R.R. and Harrison, J.J. and Hill, C. and Hodnebrog, Ø. and Hu, S.-M. and Jacquemart, D. and Jolly, A. and Jiménez, E. and Lavrentieva, N.N. and Liu, A.-W. and Lodi, L. and Lyulin, O.M. and Massie, S.T. and Mikhailenko, S. and Müller, H.S.P. and Naumenko, O.V. and Nikitin, A. and Nielsen, C.J. and Orphal, J. and Perevalov, V.I. and Perrin, A. and Polovtseva, E. and Predoi-Cross, A. and Rotger, M. and Ruth, A.A. and Yu, S.S. and Sung, K. and Tashkun, S.A. and Tennyson, J. and Tyuterev, Vl.G. and VanderAuwera, J. and Voronin, B.A. and Makie, A.},
  title = {The 2015 edition of the GEISA spectroscopic database},
  journal = {Journal of Molecular Spectroscopy},
  year = {2016},
  volume = {327},
  pages = {31 – 72},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.jms.2016.06.007}
}
Jacquinet-Husson N, Flaud J-M, Gamache RR, Predoi-Cross A and VanderAuwera J (2016), "New visions of spectroscopic databases: An introduction to the special issue", Journal of Molecular Spectroscopy. Vol. 326, pp. 1 – 4.
BibTeX:
@article{JacquinetHusson2016a,
  author = {Jacquinet-Husson, Nicole and Flaud, Jean-Marie and Gamache, Robert R. and Predoi-Cross, Adriana and VanderAuwera, J.},
  title = {New visions of spectroscopic databases: An introduction to the special issue},
  journal = {Journal of Molecular Spectroscopy},
  year = {2016},
  volume = {326},
  pages = {1 – 4},
  doi = {10.1016/j.jms.2016.07.006}
}
Jönsson P, Radžiute L, Gaigalas G, Godefroid M, Marques J, Brage T, FroeseFischer C and Grant I (2016), "Accurate multiconfiguration calculations of energy levels, lifetimes, and transition rates for the silicon isoelectronic sequence: Ti IX - Ge XIX, Sr XXV, Zr XXVII, Mo XXIX", Astronomy and Astrophysics. Vol. 585
Abstract: Multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations and relativistic configuration interaction (RCI) calculations are performed for states of the 3s23p2, 3s3p3 and 3s23p3d configurations in the Si-like ions Ti IX - Ge XIX, Sr XXV, Zr XXVII and Mo XXIX. Valence and core-valence electron correlation effects are accounted for through large configuration state function expansions. Calculated energy levels are compared with data from other calculations and with experimental data from the reference databases. Lifetime and transition rates along with uncertainty estimations are given for all ions. Energies from the calculations are in excellent agreement with observations and computed wavelength are almost of spectroscopic accuracy, aiding line identification in spectra. © 2015 ESO.
BibTeX:
@article{Joensson2016,
  author = {Jönsson, P. and Radžiute, L. and Gaigalas, G. and Godefroid, M.R. and Marques, J.P. and Brage, T. and FroeseFischer, C. and Grant, I.P.},
  title = {Accurate multiconfiguration calculations of energy levels, lifetimes, and transition rates for the silicon isoelectronic sequence: Ti IX - Ge XIX, Sr XXV, Zr XXVII, Mo XXIX},
  journal = {Astronomy and Astrophysics},
  year = {2016},
  volume = {585},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1051/0004-6361/201527106}
}
Kas M, Loreau J, Liévin J and Vaeck N (2016), "Ab initio study of reactive collisions between Rb(2 S) or Rb(2 P) and OH-(1Σ+)", Journal of Chemical Physics. Vol. 144(20)
Abstract: A theoretical rate constant for the associative detachment reaction Rb(2S) + OH-(1Σ+) → RbOH(1Σ+) + e- of 4 × 10-10 cm3 s-1 at 300 K has been calculated. This result agrees with the experimental rate constant of 2 - 1 + 2 × 1 0 - 10 cm 3 s - 1 obtained by Deiglmayr et al. [Phys. Rev. A 86, 043438 (2012)] for a temperature between 200 K and 600 K. A Langevin-based dynamics which depends on the crossing point between the anion (RbOH-) and neutral (RbOH) potential energy surfaces has been used. The calculations were performed using the ECP28MDF effective core potential to describe the rubidium atom at the CCSD(T) level of theory and extended basis sets. The effect of ECPs and basis set on the height of the crossing point, and hence the rate constant, has been investigated. The temperature dependence of the latter is also discussed. Preliminary work on the potential energy surface for the excited reaction channel Rb(2P) + OH-(1Σ+) calculated at the CASSCF-icMRCI level of theory is presented. We qualitatively discuss the charge transfer and associative detachment reactions arising from this excited entrance channel. © 2016 Author(s).
BibTeX:
@article{Kas2016,
  author = {Kas, Milaim and Loreau, Jérôme and Liévin, Jacques and Vaeck, Nathalie},
  title = {Ab initio study of reactive collisions between Rb(2 S) or Rb(2 P) and OH-(1Σ+)},
  journal = {Journal of Chemical Physics},
  year = {2016},
  volume = {144},
  number = {20},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/1.4950784}
}
Kremser S, Thomason LW, von Hobe M, Hermann M, Deshler T, Timmreck C, Toohey M, Stenke A, Schwarz JP, Weigel R, Fueglistaler S, Prata FJ, Vernier J-P, Schlager H, Barnes JE, Antuña-Marrero J-C, Fairlie D, Palm M, Mahieu E, Notholt J, Rex M, Bingen C, Vanhellemont F, Bourassa A, Plane JMC, Klocke D, Carn SA, Clarisse L, Trickl T, Neely R, James AD, Rieger L, Wilson JC and Meland B (2016), "Stratospheric aerosol—Observations, processes, and impact on climate", Reviews of Geophysics. Vol. 54(2), pp. 278 – 335.
Abstract: Interest in stratospheric aerosol and its role in climate have increased over the last decade due to the observed increase in stratospheric aerosol since 2000 and the potential for changes in the sulfur cycle induced by climate change. This review provides an overview about the advances in stratospheric aerosol research since the last comprehensive assessment of stratospheric aerosol was published in 2006. A crucial development since 2006 is the substantial improvement in the agreement between in situ and space-based inferences of stratospheric aerosol properties during volcanically quiescent periods. Furthermore, new measurement systems and techniques, both in situ and space based, have been developed for measuring physical aerosol properties with greater accuracy and for characterizing aerosol composition. However, these changes induce challenges to constructing a long-term stratospheric aerosol climatology. Currently, changes in stratospheric aerosol levels less than 20% cannot be confidently quantified. The volcanic signals tend to mask any nonvolcanically driven change, making them difficult to understand. While the role of carbonyl sulfide as a substantial and relatively constant source of stratospheric sulfur has been confirmed by new observations and model simulations, large uncertainties remain with respect to the contribution from anthropogenic sulfur dioxide emissions. New evidence has been provided that stratospheric aerosol can also contain small amounts of nonsulfate matter such as black carbon and organics. Chemistry-climate models have substantially increased in quantity and sophistication. In many models the implementation of stratospheric aerosol processes is coupled to radiation and/or stratospheric chemistry modules to account for relevant feedback processes. ©2016. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Kremser2016,
  author = {Kremser, Stefanie and Thomason, Larry W. and von Hobe, Marc and Hermann, Markus and Deshler, Terry and Timmreck, Claudia and Toohey, Matthew and Stenke, Andrea and Schwarz, Joshua P. and Weigel, Ralf and Fueglistaler, Stephan and Prata, Fred J. and Vernier, Jean-Paul and Schlager, Hans and Barnes, John E. and Antuña-Marrero, Juan-Carlos and Fairlie, Duncan and Palm, Mathias and Mahieu, Emmanuel and Notholt, Justus and Rex, Markus and Bingen, Christine and Vanhellemont, Filip and Bourassa, Adam and Plane, John M. C. and Klocke, Daniel and Carn, Simon A. and Clarisse, Lieven and Trickl, Thomas and Neely, Ryan and James, Alexander D. and Rieger, Landon and Wilson, James C. and Meland, Brian},
  title = {Stratospheric aerosol—Observations, processes, and impact on climate},
  journal = {Reviews of Geophysics},
  year = {2016},
  volume = {54},
  number = {2},
  pages = {278 – 335},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1002/2015RG000511}
}
Li J, Godefroid M and Wang J (2016), "Atomic parameters for the 2p^53p;^2[3/2]-2-2p^53s;^2[3/2]-2^otransition of Ne i relevant in nuclear physics", Journal of Physics B: Atomic, Molecular and Optical Physics. Vol. 49(11)
Abstract: We calculated the magnetic dipole hyperfine interaction constants and the electric field gradients of and levels of Ne I by using the multiconfiguration Dirac-Hartree-Fock method. The electronic factors contributing to the isotope shifts were also estimated for the transition connecting these two states. Electron correlation and relativistic effects including the Breit interaction were investigated in detail. Combining with recent measurements, we extracted the nuclear quadrupole moment values for 20Ne and 23Ne with a smaller uncertainty than the current available data. Isotope shifts in the transition based on the present calculated field- and mass-shift parameters are in good agreement with the experimental values. However, the field shifts in this transition are two or three orders of magnitude smaller than the mass shifts, making rather difficult to deduce changes in nuclear-charge mean-square radii. According to our theoretical predictions, we suggest using instead transitions connecting levels arising from the 2p53s configuration to the ground state, for which the normal mass shift and specific mass shift contributions counteract each other, producing relatively small mass shifts that are only one order of magnitude larger than relatively large field shifts, especially for the transition. © 2016 IOP Publishing Ltd.
BibTeX:
@article{Li2016,
  author = {Li, Jiguang and Godefroid, Michel and Wang, Jianguo},
  title = {Atomic parameters for the 2p^53p;^2[3/2]-2-2p^53s;^2[3/2]-2^otransition of Ne i relevant in nuclear physics},
  journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  year = {2016},
  volume = {49},
  number = {11},
  note = {All Open Access, Green Open Access},
  doi = {10.1088/0953-4075/49/11/115002}
}
Lyulin O, VanderAuwera J and Campargue A (2016), "The Fourier transform absorption spectrum of acetylene between 8280 and 8700 cm-1", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 177, pp. 234 – 240.
Abstract: High resolution (0.011 cm-1) room temperature (295 K) Fourier transform absorption spectra (FTS) of acetylene have been analyzed in the 8280-8700 cm-1 range dominated by the ν1+ν2+ν3 band at 8512 cm-1. Line positions and intensities were retrieved from FTS spectra recorded at 3.84 and 56.6 hPa. As a result, a list of 1001 lines was constructed with intensities ranging between about 2×10-26 and 10-22 cm/molecule. Comparison with accurate predictions provided by a global effective operator model led to the assignment of 629 12C2H2 lines. In addition, 114 lines of the 13C12CH2 isotopologue were assigned using information available in the literature. The 12C2H2 lines belong to thirteen bands, nine of which being newly reported. The 13C12CH2 lines belong to three bands, the intensities of which being reported for the first time. Spectroscopic parameters of the 12C2H2 upper vibrational levels were derived from band-by-band analyses of the line positions (typical rms are on the order of 0.002 cm-1). Three of the analyzed bands were found to be affected by rovibrational perturbations, which are discussed in the frame of a global effective Hamiltonian. The obtained line parameters are compared with those of the two bands included in the HITRAN 2012 database. © 2015 Elsevier Ltd.
BibTeX:
@article{Lyulin2016,
  author = {Lyulin, O.M. and VanderAuwera, J. and Campargue, A.},
  title = {The Fourier transform absorption spectrum of acetylene between 8280 and 8700 cm-1},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2016},
  volume = {177},
  pages = {234 – 240},
  doi = {10.1016/j.jqsrt.2015.11.026}
}
Perrin A, Flaud J-M, Ridolfi M, VanderAuwera J and Carlotti M (2016), "MIPAS database: New HNO3 line parameters at 7.6 μm validated with MIPAS satellite measurements", Atmospheric Measurement Techniques. Vol. 9(5), pp. 2067 – 2076.
Abstract: Improved line positions and intensities have been generated for the 7.6 m spectral region of nitric acid. They were obtained relying on a recent reinvestigation of the nitric acid band system at 7.6 m and comparisons of HNO3 volume mixing ratio profiles retrieved from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) limb emission radiances in the 11 and 7.6 m domains. This has led to an improved database called MIPAS-2015. Comparisons with available laboratory information (individual line intensities, integrated absorption cross sections, and absorption cross sections) show that MIPAS-2015 provides an improved description of the 7.6 m region of nitric acid. This study should help to improve HNO3 satellite retrievals by allowing measurements to be performed simultaneously in the 11 and 7.6 m micro-windows. In particular, it should be useful to analyze existing MIPAS and IASI spectra as well as spectra to be recorded by the forthcoming Infrared Atmospheric Sounding Interferometer-New Generation (IASI-NG) instrument. © 2016 Author(s).
BibTeX:
@article{Perrin2016,
  author = {Perrin, Agnès and Flaud, Jean-Marie and Ridolfi, Marco and VanderAuwera, Jean and Carlotti, Massimo},
  title = {MIPAS database: New HNO3 line parameters at 7.6 μm validated with MIPAS satellite measurements},
  journal = {Atmospheric Measurement Techniques},
  year = {2016},
  volume = {9},
  number = {5},
  pages = {2067 – 2076},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-9-2067-2016}
}
Pommier M, Clerbaux C, Coheur P-F, Mahieu E, Müller J-F, Paton-Walsh C, Stavrakou T and Vigouroux C (2016), "HCOOH distributions from IASI for 2008-2014: Comparison with ground-based FTIR measurements and a global chemistry-transport model", Atmospheric Chemistry and Physics. Vol. 16(14), pp. 8963 – 8981.
Abstract: Formic acid (HCOOH) is one of the most abundant volatile organic compounds in the atmosphere. It is a major contributor to rain acidity in remote areas. There are, however, large uncertainties on the sources and sinks of HCOOH and therefore HCOOH is misrepresented by global chemistry-transport models. This work presents global distributions from 2008 to 2014 as derived from the measurements of the Infrared Atmospheric Sounding Interferometer (IASI), based on conversion factors between brightness temperature differences and representative retrieved total columns over seven regions: Northern Africa, southern Africa, Amazonia, Atlantic, Australia, Pacific, and Russia. The dependence of the measured HCOOH signal on the thermal contrast is taken into account in the conversion method. This conversion presents errors lower than 20% for total columns ranging between 0.5 and 1×1016 molec cm-2 but reaches higher values, up to 78 %, for columns that are lower than 0:3×1016 molec cm-2. Signatures from biomass burning events are highlighted, such as in the Southern Hemisphere and in Russia, as well as biogenic emission sources, e.g., over the eastern USA. A comparison between 2008 and 2014 with ground-based Fourier transform infrared spectroscopy (FTIR) measurements obtained at four locations (Maido and Saint-Denis at La Réunion, Jungfraujoch, and Wollongong) is shown. Although IASI columns are found to correlate well with FTIR data, a large bias (> 100 %) is found over the two sites at La Réunion. A better agreement is found at Wollongong with a negligible bias. The comparison also highlights the difficulty of retrieving total columns from IASI measurements over mountainous regions such as Jungfraujoch. A comparison of the retrieved columns with the global chemistry-transport model IMAGESv2 is also presented, showing good representation of the seasonal and interannual cycles over America, Australia, Asia, and Siberia. A global model underestimation of the distribution and a misrepresentation of the seasonal cycle over India are also found. A small positive trend in the IASI columns is observed over Australia, Amazonia, and India over the 2008-2014 period (from 0.7 to 1.5%year-1), while a decrease of ∼0.8% year-1 is measured over Siberia. © Author(s) 2016.
BibTeX:
@article{Pommier2016,
  author = {Pommier, Matthieu and Clerbaux, Cathy and Coheur, Pierre-François and Mahieu, Emmanuel and Müller, Jean-François and Paton-Walsh, Clare and Stavrakou, Trissevgeni and Vigouroux, Corinne},
  title = {HCOOH distributions from IASI for 2008-2014: Comparison with ground-based FTIR measurements and a global chemistry-transport model},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {14},
  pages = {8963 – 8981},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-8963-2016}
}
Popp T, De Leeuw G, Bingen C, Brühl C, Capelle V, Chedin A, Clarisse L, Dubovik O, Grainger R, Griesfeller J, Heckel A, Kinne S, Klüser L, Kosmale M, Kolmonen P, Lelli L, Litvinov P, Mei L, North P, Pinnock S, Povey A, Robert C, Schulz M, Sogacheva L, Stebel K, Zweers DS, Thomas G, Tilstra LG, Vandenbussche S, Veefkind P, Vountas M and Xue Y (2016), "Development, production and evaluation of aerosol climate data records from European satellite observations (Aerosol_cci)", Remote Sensing. Vol. 8(5)
Abstract: Producing a global and comprehensive description of atmospheric aerosols requires integration of ground-based, airborne, satellite and model datasets. Due to its complexity, aerosol monitoring requires the use of several data records with complementary information content. This paper describes the lessons learned while developing and qualifying algorithms to generate aerosol Climate Data Records (CDR) within the European Space Agency (ESA) Aerosol_cci project. An iterative algorithm development and evaluation cycle involving core users is applied. It begins with the application-specific refinement of user requirements, leading to algorithm development, dataset processing and independent validation followed by user evaluation. This cycle is demonstrated for a CDR of total Aerosol Optical Depth (AOD) from two subsequent dual-view radiometers. Specific aspects of its applicability to other aerosol algorithms are illustrated with four complementary aerosol datasets. An important element in the development of aerosol CDRs is the inclusion of several algorithms evaluating the same data to benefit from various solutions to the ill-determined retrieval problem. The iterative approach has produced a 17-year AOD CDR, a 10-year stratospheric extinction profile CDR and a 35-year Absorbing Aerosol Index record. Further evolution cycles have been initiated for complementary datasets to provide insight into aerosol properties (i.e., dust aerosol, aerosol absorption). © 2016 by the authors.
BibTeX:
@article{Popp2016,
  author = {Popp, Thomas and De Leeuw, Gerrit and Bingen, Christine and Brühl, Christoph and Capelle, Virginie and Chedin, Alain and Clarisse, Lieven and Dubovik, Oleg and Grainger, Roy and Griesfeller, Jan and Heckel, Andreas and Kinne, Stefan and Klüser, Lars and Kosmale, Miriam and Kolmonen, Pekka and Lelli, Luca and Litvinov, Pavel and Mei, Linlu and North, Peter and Pinnock, Simon and Povey, Adam and Robert, Charles and Schulz, Michael and Sogacheva, Larisa and Stebel, Kerstin and Zweers, Deborah Stein and Thomas, Gareth and Tilstra, Lieuwe Gijsbert and Vandenbussche, Sophie and Veefkind, Pepijn and Vountas, Marco and Xue, Yong},
  title = {Development, production and evaluation of aerosol climate data records from European satellite observations (Aerosol_cci)},
  journal = {Remote Sensing},
  year = {2016},
  volume = {8},
  number = {5},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.3390/rs8050421}
}
Predoi-Cross A, Unni A, Liu W, Schofield I, Holladay C, McKellar A and Hurtmans D (2016), "Corrigendum to "Line shape parameters measurement and computations for self-broadened carbon dioxide transitions in the 30012 ← 00001 and 30013 ← 00001 bands, line mixing, and speed dependence" [J. Mol. Spectrosc. 245 (2007) 34-51]", Journal of Molecular Spectroscopy. Vol. 322, pp. 55.
BibTeX:
@article{PredoiCross2016,
  author = {Predoi-Cross, A. and Unni, A.V. and Liu, W. and Schofield, I. and Holladay, C. and McKellar, A.R.W. and Hurtmans, D.},
  title = {Corrigendum to "Line shape parameters measurement and computations for self-broadened carbon dioxide transitions in the 30012 ← 00001 and 30013 ← 00001 bands, line mixing, and speed dependence" [J. Mol. Spectrosc. 245 (2007) 34-51]},
  journal = {Journal of Molecular Spectroscopy},
  year = {2016},
  volume = {322},
  pages = {55},
  doi = {10.1016/j.jms.2015.11.005}
}
Quennehen B, Raut J-C, Law K, Daskalakis N, Ancellet G, Clerbaux C, Kim S-W, Lund M, Myhre G, Olivié D, Safieddine S, Skeie R, Thomas J, Tsyro S, Bazureau A, Bellouin N, Hu M, Kanakidou M, Klimont Z, Kupiainen K, Myriokefalitakis S, Quaas J, Rumbold S, Schulz M, Cherian R, Shimizu A, Wang J, Yoon S-C and Zhu T (2016), "Multi-model evaluation of short-lived pollutant distributions over east Asia during summer 2008", Atmospheric Chemistry and Physics. Vol. 16(17), pp. 10765 – 10792.
Abstract: The ability of seven state-of-the-art chemistry-aerosol models to reproduce distributions of tropospheric ozone and its precursors, as well as aerosols over eastern Asia in summer 2008, is evaluated. The study focuses on the performance of models used to assess impacts of pollutants on climate and air quality as part of the EU ECLIPSE project. Models, run using the same ECLIPSE emissions, are compared over different spatial scales to in situ surface, vertical profiles and satellite data. Several rather clear biases are found between model results and observations, including overestimation of ozone at rural locations downwind of the main emission regions in China, as well as downwind over the Pacific. Several models produce too much ozone over polluted regions, which is then transported downwind. Analysis points to different factors related to the ability of models to simulate VOC-limited regimes over polluted regions and NOx limited regimes downwind. This may also be linked to biases compared to satellite NO2, indicating overestimation of NO2 over and to the north of the northern China Plain emission region. On the other hand, model NO2 is too low to the south and west of this region and over South Korea/Japan. Overestimation of ozone is linked to systematic underestimation of CO particularly at rural sites and downwind of the main Chinese emission regions. This is likely to be due to enhanced destruction of CO by OH. Overestimation of Asian ozone and its transport downwind implies that radiative forcing from this source may be overestimated. Model-observation discrepancies over Beijing do not appear to be due to emission controls linked to the Olympic Games in summer 2008.

With regard to aerosols, most models reproduce the satellite-derived AOD patterns over eastern China. Our study nevertheless reveals an overestimation of ECLIPSE model mean surface BC and sulphate aerosols in urban China in summer 2008. The effect of the short-term emission mitigation in Beijing is too weak to explain the differences between the models. Our results rather point to an overestimation of SO2 emissions, in particular, close to the surface in Chinese urban areas. However, we also identify a clear underestimation of aerosol concentrations over northern India, suggesting that the rapid recent growth of emissions in India, as well as their spatial extension, is underestimated in emission inventories. Model deficiencies in the representation of pollution accumulation due to the Indian monsoon may also be playing a role. Comparison with vertical aerosol lidar measurements highlights a general underestimation of scattering aerosols in the boundary layer associated with overestimation in the free troposphere pointing to modelled aerosol lifetimes that are too long. This is likely linked to too strong vertical transport and/or insufficient deposition efficiency during transport or export from the boundary layer, rather than chemical processing (in the case of sulphate aerosols). Underestimation of sulphate in the boundary layer implies potentially large errors in simulated aerosol-cloud interactions, via impacts on boundary-layer clouds.

This evaluation has important implications for accurate assessment of air pollutants on regional air quality and global climate based on global model calculations. Ideally, models should be run at higher resolution over source regions to better simulate urban-rural pollutant gradients and/or chemical regimes, and also to better resolve pollutant processing and loss by wet deposition as well as vertical transport. Discrepancies in vertical distributions require further quantification and improvement since these are a key factor in the determination of radiative forcing from short-lived pollutants.
BibTeX:
@article{Quennehen2016,
  author = {Quennehen, B. and Raut, J.-C. and Law, K.S. and Daskalakis, N. and Ancellet, G. and Clerbaux, C. and Kim, S.-W. and Lund, M.T. and Myhre, G. and Olivié, D.J.L. and Safieddine, S. and Skeie, R.B. and Thomas, J.L. and Tsyro, S. and Bazureau, A. and Bellouin, N. and Hu, M. and Kanakidou, M. and Klimont, Z. and Kupiainen, K. and Myriokefalitakis, S. and Quaas, J. and Rumbold, S.T. and Schulz, M. and Cherian, R. and Shimizu, A. and Wang, J. and Yoon, S.-C. and Zhu, T.},
  title = {Multi-model evaluation of short-lived pollutant distributions over east Asia during summer 2008},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {17},
  pages = {10765 – 10792},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-10765-2016}
}
Robert S, Vandaele A, Thomas I, Willame Y, Daerden F, Delanoye S, Depiesse C, Drummond R, Neefs E, Neary L, Ristic B, Mason J, Lopez-Moreno J-J, Rodriguez-Gomez J, Patel M, Bellucci G, Patel M, Allen M, Altieri F, Aoki S, Bolsée D, Clancy T, Cloutis E, Fedorova A, Formisano V, Funke B, Fussen D, Garcia-Comas M, Geminale A, Gérard J-C, Gillotay D, Giuranna M, Gonzalez-Galindo F, Igna-Tiev N, Kaminski J, Karatekin O, Kasaba Y, Lefèvre F, Lewis S, López-Puertas M, López-Valverde M, Mahieux A, McConnell J, Mumma M, Novak R, Renotte E, Sindoni G, Smith M, Trokhimovskiy A, Vander AJ, Villanueva G, Viscardy S, Whiteway J, Wilquet V, Wolff M, Alonso-Rodrigo G, Aparicio Del Moral B, Barzin P, Benmoussa A, Berkenbosch S, Biondi D, Bonnewijn S, Candini G, Clairquin R, Cubas J, Giordanengo B, Gissot S, Gomez A, Zafra J-J, Leese M, Maes J, Mazy E, Mazzoli A, Meseguer J, Morales R, Orban A, Pastor-Morales M, Perez-Grande I, Saggin B, Samain V, Sanz AA, Sanz R, Simar J-F and Thibert T (2016), "Expected performances of the NOMAD/ExoMars instrument", Planetary and Space Science. Vol. 124, pp. 94 – 104.
Abstract: NOMAD (Nadir and Occultation for MArs Discovery) is one of the four instruments on board the ExoMars Trace Gas Orbiter, scheduled for launch in March 2016. It consists of a suite of three high-resolution spectrometers - SO (Solar Occultation), LNO (Limb, Nadir and Occultation) and UVIS (Ultraviolet and Visible Spectrometer). Based upon the characteristics of the channels and the values of Signal-to-Noise Ratio obtained from radiometric models discussed in (Vandaele et al., 2015a, 2015b; Thomas et al., 2016), the expected performances of the instrument in terms of sensitivity to detection have been investigated. The analysis led to the determination of detection limits for 18 molecules, namely CO, H 2 O, HDO, C 2 H 2 , C 2 H 4 , C 2 H 6 , H 2 CO, CH 4 , SO 2 , H 2 S, HCl, HCN, HO 2 , NH 3 , N 2 O, NO 2 , OCS, O 3 . NOMAD should have the ability to measure methane concentrations < 25 parts per trillion (ppt) in solar occultation mode, and 11 parts per billion in nadir mode. Occultation detections as low as 10 ppt could be made if spectra are averaged (Drummond et al., 2011). Results have been obtained for all three channels in nadir and in solar occultation. © 2016 The Authors. Published by Elsevier Ltd.
BibTeX:
@article{Robert2016,
  author = {Robert, S. and Vandaele, A.C. and Thomas, I. and Willame, Y. and Daerden, F. and Delanoye, S. and Depiesse, C. and Drummond, R. and Neefs, E. and Neary, L. and Ristic, B. and Mason, J. and Lopez-Moreno, J.-J. and Rodriguez-Gomez, J. and Patel, M.R. and Bellucci, G. and Patel, M. and Allen, M. and Altieri, F. and Aoki, S. and Bolsée, D. and Clancy, T. and Cloutis, E. and Fedorova, A. and Formisano, V. and Funke, B. and Fussen, D. and Garcia-Comas, M. and Geminale, A. and Gérard, J.-C. and Gillotay, D. and Giuranna, M. and Gonzalez-Galindo, F. and Igna-Tiev, N. and Kaminski, J. and Karatekin, O. and Kasaba, Y. and Lefèvre, F. and Lewis, S. and López-Puertas, M. and López-Valverde, M. and Mahieux, A. and McConnell, J. and Mumma, M. and Novak, R. and Renotte, E. and Sindoni, G. and Smith, M. and Trokhimovskiy, A. and Vander, Auwera J. and Villanueva, G. and Viscardy, S. and Whiteway, J. and Wilquet, V. and Wolff, M. and Alonso-Rodrigo, G. and Aparicio Del Moral, B. and Barzin, P. and Benmoussa, A. and Berkenbosch, S. and Biondi, D. and Bonnewijn, S. and Candini, G. and Clairquin, R. and Cubas, J. and Giordanengo, B. and Gissot, S. and Gomez, A. and Zafra, J.-J. and Leese, M. and Maes, J. and Mazy, E. and Mazzoli, A. and Meseguer, J. and Morales, R. and Orban, A. and Pastor-Morales, M. and Perez-Grande, I. and Saggin, B. and Samain, V. and Sanz, Andres A. and Sanz, R. and Simar, J.-F. and Thibert, T.},
  title = {Expected performances of the NOMAD/ExoMars instrument},
  journal = {Planetary and Space Science},
  year = {2016},
  volume = {124},
  pages = {94 – 104},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.1016/j.pss.2016.03.003}
}
Ronsmans G, Langerock B, Wespes C, Hannigan JW, Hase F, Kerzenmacher T, Mahieu E, Schneider M, Smale D, Hurtmans D, De Mazière M, Clerbaux C and Coheur P-F (2016), "First characterization and validation of FORLI-HNO3 vertical profiles retrieved from IASI/Metop", Atmospheric Measurement Techniques. Vol. 9(9), pp. 4783 – 4801.
Abstract: Knowing the spatial and seasonal distributions of nitric acid (HNO3/ around the globe is of great interest and allows us to comprehend the processes regulating stratospheric ozone, especially in the polar regions. Due to its unprecedented spatial and temporal sampling, the nadir-viewing Infrared Atmospheric Sounding Interferometer (IASI) is capable of sounding the atmosphere twice a day globally, with good spectral resolution and low noise. With the Fast Optimal Retrievals on Layers for IASI (FORLI) algorithm, we are retrieving, in near real time, columns as well as vertical profiles of several atmospheric species, among which is HNO3. We present in this paper the first characterization of the FORLI-HNO3 profile products, in terms of vertical sensitivity and error budgets. We show that the sensitivity of IASI to HNO3 is highest in the lower stratosphere (10-20 km), where the largest amounts of HNO3 are found, but that the vertical sensitivity of IASI only allows one level of information on the profile (degrees of freedom for signal, DOFS; ∼1). The sensitivity near the surface is negligible in most cases, and for this reason, a partial column (5-35 km) is used for the analyses. Both vertical profiles and partial columns are compared to FTIR ground-based measurements from the Network for the Detection of Atmospheric Composition Change (NDACC) to characterize the accuracy and precision of the FORLI-HNO3 product. The profile validation is conducted through the smoothing of the raw FTIR profiles by the IASI averaging kernels and gives good results, with a slight overestimation of IASI measurements in the upper troposphere/lower stratosphere (UTLS) at the six chosen stations (Thule, Kiruna, Jungfraujoch, Izaña, Lauder and Arrival Heights). The validation of the partial columns (5-35 km) is also conclusive with a mean correlation of 0.93 between IASI and the FTIR measurements. An initial survey of the HNO3 spatial and seasonal variabilities obtained from IASI measurements for a 1-year (2011) data set shows that the expected latitudinal gradient of concentrations from low to high latitudes and the large seasonal variability in polar regions (cycle amplitude around 30% of the seasonal signal, peak to peak) are well represented by IASI data. © Author(s) 2016.
BibTeX:
@article{Ronsmans2016,
  author = {Ronsmans, Gaétane and Langerock, Bavo and Wespes, Catherine and Hannigan, James W. and Hase, Frank and Kerzenmacher, Tobias and Mahieu, Emmanuel and Schneider, Matthias and Smale, Dan and Hurtmans, Daniel and De Mazière, Martine and Clerbaux, Cathy and Coheur, Pierre-François},
  title = {First characterization and validation of FORLI-HNO3 vertical profiles retrieved from IASI/Metop},
  journal = {Atmospheric Measurement Techniques},
  year = {2016},
  volume = {9},
  number = {9},
  pages = {4783 – 4801},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-9-4783-2016}
}
Safieddine S, Boynard A, Hao N, Huang F, Wang L, Ji D, Barret B, Ghude SD, Coheur P-F, Hurtmans D and Clerbaux C (2016), "Tropospheric ozone variability during the East Asian summer monsoon as observed by satellite (IASI), aircraft (MOZAIC) and ground stations", Atmospheric Chemistry and Physics. Vol. 16(16), pp. 10489 – 10500.
Abstract: Satellite measurements from the thermal Infrared Atmospheric Sounding Interferometer (IASI), aircraft data from the MOZAIC/IAGOS project, as well as observations from ground-based stations, are used to assess the tropospheric ozone (O3) variability during the East Asian Summer Monsoon (EASM). Six years 2008-2013 of IASI data analysis reveals the ability of the instrument to detect the onset and the progression of the monsoon seen by a decrease in the tropospheric 0-6km O3 column due to the EASM, and to reproduce this decrease from one year to the other. The year-to-year variability is found to be mainly dependent on meteorology. Focusing on the period of May-August 2011, taken as an example year, IASI data show clear inverse relationship between tropospheric 0-6km O3 on one hand and meteorological parameters such as cloud cover, relative humidity and wind speed, on the other hand. Aircraft data from the MOZAIC/IAGOS project for the EASM of 2008-2013 are used to validate the IASI data and to assess the effect of the monsoon on the vertical distribution of the tropospheric O3 at different locations. Results show good agreement with a correlation coefficient of 0.73 (12%) between the 0-6km O3 column derived from IASI and aircraft data. IASI captures very well the inter-annual variation of tropospheric O3 observed by the aircraft data over the studied domain. Analysis of vertical profiles of the aircraft data shows a decrease in the tropospheric O3 that is more important in the free troposphere than in the boundary layer and at 10-20°N than elsewhere. Ground station data at different locations in India and China show a spatiotemporal dependence on meteorology during the monsoon, with a decrease up to 22ppbv in Hyderabad, and up to 5ppbv in the North China Plain. © Author(s) 2016.
BibTeX:
@article{Safieddine2016,
  author = {Safieddine, Sarah and Boynard, Anne and Hao, Nan and Huang, Fuxiang and Wang, Lili and Ji, Dongsheng and Barret, Brice and Ghude, Sachin D. and Coheur, Pierre-Franois and Hurtmans, Daniel and Clerbaux, Cathy},
  title = {Tropospheric ozone variability during the East Asian summer monsoon as observed by satellite (IASI), aircraft (MOZAIC) and ground stations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {16},
  pages = {10489 – 10500},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-10489-2016}
}
Schiferl LD, Heald CL, Damme MV, Clarisse L, Clerbaux C, Coheur P-F, Nowak JB, Neuman JA, Herndon SC, Roscioli JR and Eilerman SJ (2016), "Interannual variability of ammonia concentrations over the United States: Sources and implications", Atmospheric Chemistry and Physics. Vol. 16(18), pp. 12305 – 12328.
Abstract: The variability of atmospheric ammonia (NH3), emitted largely from agricultural sources, is an important factor when considering how inorganic fine particulate matter (PM2.5) concentrations and nitrogen cycling are changing over the United States. This study combines new observations of ammonia concentration from the surface, aboard aircraft, and retrieved by satellite to both evaluate the simulation of ammonia in a chemical transport model (GEOS-Chem) and identify which processes control the variability of these concentrations over a 5-year period (2008-2012). We find that the model generally underrepresents the ammonia concentration near large source regions (by 26% at surface sites) and fails to reproduce the extent of interannual variability observed at the surface during the summer (JJA). Variability in the base simulation surface ammonia concentration is dominated by meteorology (64%) as compared to reductions in SO2 and NOx emissions imposed by regulation (32%) over this period. Introduction of year-to-year varying ammonia emissions based on animal population, fertilizer application, and meteorologically driven volatilization does not substantially improve the model comparison with observed ammonia concentrations, and these ammonia emissions changes have little effect on the simulated ammonia concentration variability compared to those caused by the variability of meteorology and acid-precursor emissions. There is also little effect on the PM2.5 concentration due to ammonia emissions variability in the summer when gas-phase changes are favored, but variability in wintertime emissions, as well as in early spring and late fall, will have a larger impact on PM2.5 formation. This work highlights the need for continued improvement in both satellite-based and in situ ammonia measurements to better constrain the magnitude and impacts of spatial and temporal variability in ammonia concentrations. © 2016 The Author(s).
BibTeX:
@article{Schiferl2016,
  author = {Schiferl, Luke D. and Heald, Colette L. and Damme, Martin Van and Clarisse, Lieven and Clerbaux, Cathy and Coheur, Pierre-François and Nowak, John B. and Neuman, J. Andrew and Herndon, Scott C. and Roscioli, Joseph R. and Eilerman, Scott J.},
  title = {Interannual variability of ammonia concentrations over the United States: Sources and implications},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {18},
  pages = {12305 – 12328},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-12305-2016}
}
Stavrakou T, Müller J-F, Bauwens M, De Smedt I, Lerot C, vanRoozendael M, Coheur P-F, Clerbaux C, Boersma K, Van Der A and Song Y (2016), "Substantial Underestimation of Post-Harvest Burning Emissions in the North China Plain Revealed by Multi-Species Space Observations", Scientific Reports. Vol. 6
Abstract: The large-scale burning of crop residues in the North China Plain (NCP), one of the most densely populated world regions, was recently recognized to cause severe air pollution and harmful health effects. A reliable quantification of the magnitude of these fires is needed to assess regional air quality. Here, we use an eight-year record (2005-2012) of formaldehyde measurements from space to constrain the emissions of volatile organic compounds (VOCs) in this region. Using inverse modelling, we derive that satellite-based post-harvest burning fluxes are, on average, at least a factor of 2 higher than state-of-the-art bottom-up statistical estimates, although with significant interannual variability. Crop burning is calculated to cause important increases in surface ozone (+7%) and fine aerosol concentrations (+18%) in the North China Plain in June. The impact of crop fires is also found in satellite observations of other species, glyoxal, nitrogen dioxide and methanol, and we show that those measurements validate the magnitude of the top-down fluxes. Our study indicates that the top-down crop burning fluxes of VOCs in June exceed by almost a factor of 2 the combined emissions from other anthropogenic activities in this region, underscoring the need for targeted actions towards changes in agricultural management practices. © 2016 The Author(s).
BibTeX:
@article{Stavrakou2016,
  author = {Stavrakou, T. and Müller, J.-F. and Bauwens, M. and De Smedt, I. and Lerot, C. and vanRoozendael, M. and Coheur, P.-F. and Clerbaux, C. and Boersma, K.F. and Van Der, A.R. and Song, Y.},
  title = {Substantial Underestimation of Post-Harvest Burning Emissions in the North China Plain Revealed by Multi-Species Space Observations},
  journal = {Scientific Reports},
  year = {2016},
  volume = {6},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1038/srep32307}
}
Sullivan R, Crippa P, Hallar A, Clarisse L, Whitburn S, VanDamme M, Leaitch W, Walker J, Khlystov A and Pryor S (2016), "Using satellite-based measurements to explore spatiotemporal scales and variability of drivers of new particle formation", Journal of Geophysical Research. Vol. 121(20), pp. 12,217 – 12,235.
Abstract: New particle formation (NPF) can potentially alter regional climate by increasing aerosol particle (hereafter particle) number concentrations and ultimately cloud condensation nuclei. The large scales on which NPF is manifest indicate potential to use satellite-based (inherently spatially averaged) measurements of atmospheric conditions to diagnose the occurrence of NPF and NPF characteristics. We demonstrate the potential for using satellite-based measurements of insolation (UV), trace gas concentrations (sulfur dioxide (SO2), nitrogen dioxide (NO2), ammonia (NH3), formaldehyde (HCHO), and ozone (O3)), aerosol optical properties (aerosol optical depth (AOD) and Ångström exponent (AE)), and a proxy of biogenic volatile organic compound emissions (leaf area index (LAI) and temperature (T)) as predictors for NPF characteristics: formation rates, growth rates, survival probabilities, and ultrafine particle (UFP) concentrations at five locations across North America. NPF at all sites is most frequent in spring, exhibits a one-day autocorrelation, and is associated with low condensational sink(AOD × AE) andHCHOconcentrations, and high UV. However, there are important site-to-site variations in NPF frequency and characteristics, and in which of the predictor variables (particularly gas concentrations) significantly contribute to the explanatory power of regression models built to predict those characteristics. This finding may provide a partial explanation for the reported spatial variability in skill of simple generalized nucleation schemes in reproducing observed NPF. In contrast to more simple proxies developed in prior studies (e.g., based on AOD, AE, SO2, and UV), use of additional predictors (NO2, NH3, HCHO, LAI, T, and O3) increases the explained temporal variance of UFP concentrations at all sites. © 2016. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Sullivan2016,
  author = {Sullivan, R.C. and Crippa, P. and Hallar, A.G. and Clarisse, L. and Whitburn, S. and VanDamme, Martin and Leaitch, W.R. and Walker, J.T. and Khlystov, A. and Pryor, S.C.},
  title = {Using satellite-based measurements to explore spatiotemporal scales and variability of drivers of new particle formation},
  journal = {Journal of Geophysical Research},
  year = {2016},
  volume = {121},
  number = {20},
  pages = {12,217 – 12,235},
  note = {All Open Access, Green Open Access},
  doi = {10.1002/2016JD025568}
}
Té Y, Jeseck P, Franco B, Mahieu E, Jones N, Paton-Walsh C, Griffith DWT, Buchholz RR, Hadji-Lazaro J, Hurtmans D and Janssen C (2016), "Seasonal variability of surface and column carbon monoxide over the megacity Paris, high-altitude Jungfraujoch and Southern Hemispheric Wollongong stations", Atmospheric Chemistry and Physics. Vol. 16(17), pp. 10911 – 10925.
Abstract: This paper studies the seasonal variation of surface and column CO at three different sites (Paris, Jungfraujoch and Wollongong), with an emphasis on establishing a link between the CO vertical distribution and the nature of CO emission sources. We find the first evidence of a time lag between surface and free tropospheric CO seasonal variations in the Northern Hemisphere. The CO seasonal variability obtained from the total columns and free tropospheric partial columns shows a maximum around March-April and a minimum around September-October in the Northern Hemisphere (Paris and Jungfraujoch). In the Southern Hemisphere (Wollongong) this seasonal variability is shifted by about 6 months. Satellite observations by the IASI-MetOp (Infrared Atmospheric Sounding Interferometer) and MOPITT (Measurements Of Pollution In The Troposphere) instruments confirm this seasonality. Ground-based FTIR (Fourier transform infrared) measurements provide useful complementary information due to good sensitivity in the boundary layer. In situ surface measurements of CO volume mixing ratios at the Paris and Jungfraujoch sites reveal a time lag of the near-surface seasonal variability of about 2 months with respect to the total column variability at the same sites. The chemical transport model GEOS-Chem (Goddard Earth Observing System chemical transport model) is employed to interpret our observations. GEOS-Chem sensitivity runs identify the emission sources influencing the seasonal variation of CO. At both Paris and Jungfraujoch, the surface seasonality is mainly driven by anthropogenic emissions, while the total column seasonality is also controlled by air masses transported from distant sources. At Wollongong, where the CO seasonality is mainly affected by biomass burning, no time shift is observed between surface measurements and total column data. © Author(s) 2016. CC Attribution 3.0 License.
BibTeX:
@article{Te2016,
  author = {Té, Yao and Jeseck, Pascal and Franco, Bruno and Mahieu, Emmanuel and Jones, Nicholas and Paton-Walsh, Clare and Griffith, David W. T. and Buchholz, Rebecca R. and Hadji-Lazaro, Juliette and Hurtmans, Daniel and Janssen, Christof},
  title = {Seasonal variability of surface and column carbon monoxide over the megacity Paris, high-altitude Jungfraujoch and Southern Hemispheric Wollongong stations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {17},
  pages = {10911 – 10925},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-10911-2016}
}
Thomas I, Vandaele A, Robert S, Neefs E, Drummond R, Daerden F, Delanoye S, Ristic B, Berkenbosch S, Clairquin R, Maes J, Bonnewijn S, Depiesse C, Mahieux A, Trompet L, Neary L, Willame Y, Wilquet V, Nevejans D, Aballea L, Moelans W, De Vos L, Lesschaeve S, Van Vooren N, Lopez-Moreno J-J, Patel M, Bellucci G, Allen M, Altieri F, Aoki S, Bolsée D, Clancy T, Cloutis E, Fedorova A, Formisano V, Funke B, Fussen D, Garcia-Comas M, Geminale A, Gérard J-C, Gillotay D, Giuranna M, Gonzalez-Galindo F, Ignatiev N, Kaminski J, Karatekin O, Kasaba Y, Lefèvre F, Lewis S, López-Puertas M, López-Valverde M, Mason J, McConnell J, Mumma M, Novak R, Renotte E, Sindoni G, Smith M, Trokhimovsky S, VanderAuwera J, Villanueva G, Whiteway J, Wolff M, Alonso-Rodrigo G, Aparicio Del Moral B, Barzin P, BenMoussa A, Biondi D, Candini GP, Cubas J, Giordanengo B, Gissot S, Gomez A, Zafra J-J, Leese M, Mazy E, Mazzoli A, Meseguer J, Morales R, Orban A, Pastor-Morales MDC, Perez-Grande I, Rodriguez-Gomez J, Saggin B, Samain V, Sanz Andres A, Sanz R, Simar J-F and Thibert T (2016), "Optical and radiometric models of the NOMAD instrument Part II: The infrared channels - SO and LNO", Optics Express. Vol. 24(4), pp. 3790 – 3805.
Abstract: NOMAD is a suite of three spectrometers that will be launched in 2016 as part of the joint ESA-Roscosmos ExoMars Trace Gas Orbiter mission. The instrument contains three channels that cover the IR and UV spectral ranges and can perform solar occultation, nadir and limb observations, to detect and map a wide variety of Martian atmospheric gases and trace species. Part I of this work described the models of the UVIS channel; in this second part, we present the optical models representing the two IR channels, SO (Solar Occultation) and LNO (Limb, Nadir and Occultation), and use them to determine signal to noise ratios (SNRs) for many expected observational cases. In solar occultation mode, both the SO and LNO channel exhibit very high SNRs >5000. SNRs of around 100 were found for the LNO channel in nadir mode, depending on the atmospheric conditions, Martian surface properties, and observation geometry. © 2016 Optical Society of America.
BibTeX:
@article{Thomas2016,
  author = {Thomas, I.R. and Vandaele, A.C. and Robert, S. and Neefs, E. and Drummond, R. and Daerden, F. and Delanoye, S. and Ristic, B. and Berkenbosch, S. and Clairquin, R. and Maes, J. and Bonnewijn, S. and Depiesse, C. and Mahieux, A. and Trompet, L. and Neary, L. and Willame, Y. and Wilquet, V. and Nevejans, D. and Aballea, L. and Moelans, W. and De Vos, L. and Lesschaeve, S. and Van Vooren, N. and Lopez-Moreno, J.-J. and Patel, M.R. and Bellucci, G. and Allen, Mark and Altieri, Francesca and Aoki, Shohei and Bolsée, David and Clancy, Todd and Cloutis, Edward and Fedorova, Anna and Formisano, Vittorio and Funke, Bernd and Fussen, Didier and Garcia-Comas, Maya and Geminale, Anna and Gérard, Jean-Claude and Gillotay, Didier and Giuranna, Marco and Gonzalez-Galindo, Francisco and Ignatiev, Nicolai and Kaminski, Jacek and Karatekin, Ozgur and Kasaba, Yasumasa and Lefèvre, Franck and Lewis, Stephen and López-Puertas, Manuel and López-Valverde, Miguel and Mason, Jon and McConnell, Jack and Mumma, Mike and Novak, Robert and Renotte, Etienne and Sindoni, Giuseppe and Smith, Mike and Trokhimovsky, Sacha and VanderAuwera, Jean and Villanueva, Geronimo and Whiteway, Jim and Wolff, Mike and Alonso-Rodrigo, Gustavo and Aparicio Del Moral, Beatriz and Barzin, Pascal and BenMoussa, Ali and Biondi, David and Candini, Gian Paolo and Cubas, Javier and Giordanengo, Boris and Gissot, Samuel and Gomez, Alejandro and Zafra, Jose-Jeronimo and Leese, Mark and Mazy, Emmanuel and Mazzoli, Alexandra and Meseguer, Jose and Morales, Rafael and Orban, Anne and Pastor-Morales, Maria Del Carmen and Perez-Grande, Isabel and Rodriguez-Gomez, Julio and Saggin, Bortolino and Samain, Valérie and Sanz Andres, Angel and Sanz, Rosario and Simar, Juan-Felipe and Thibert, Tanguy},
  title = {Optical and radiometric models of the NOMAD instrument Part II: The infrared channels - SO and LNO},
  journal = {Optics Express},
  year = {2016},
  volume = {24},
  number = {4},
  pages = {3790 – 3805},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1364/OE.24.003790}
}
VanderAuwera J, Boulet C, Carré Y, Kocon L and Hartmann J-M (2016), "Confinement-induced infrared absorption by H2 and N2 gases in a porous silica aerogel", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 182, pp. 193 – 198.
Abstract: Transmission spectra in the fundamental bands of H2 and N2 gas inside the pores of a silica aerogel sample were recorded at room temperature and for several pressures using a Fourier transform spectrometer. They first show that, as the absorption is proportional to the pressure, it is due to the interactions of the molecules with the inner surfaces of the pores and not to the dipole induced during gas-phase molecule-molecule collisions. Furthermore, the analysis of the widths and areas of the observed absorption structures indicate that, for the considered aerogel sample, most of the absorption is likely due to "free" molecules moving within the pores with a weak contribution of adsorbed molecules. © 2016 Elsevier Ltd.
BibTeX:
@article{VanderAuwera2016,
  author = {VanderAuwera, J. and Boulet, C. and Carré, Y. and Kocon, L. and Hartmann, J.-M.},
  title = {Confinement-induced infrared absorption by H2 and N2 gases in a porous silica aerogel},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2016},
  volume = {182},
  pages = {193 – 198},
  doi = {10.1016/j.jqsrt.2016.05.032}
}
Vegvari C, Cauët E, Hadjichrysanthou C, Lawrence E, Weverling G-J, De Wolf F and Anderson RM (2016), "Using clinical trial simulators to analyse the sources of variance in clinical trials of novel therapies for acute viral infections", PLoS ONE. Vol. 11(6)
Abstract: Background About 90% of drugs fail in clinical development. The question is whether trials fail because of insufficient efficacy of the new treatment, or rather because of poor trial design that is unable to detect the true efficacy. The variance of the measured endpoints is a major, largely underestimated source of uncertainty in clinical trial design, particularly in acute viral infections. We use a clinical trial simulator to demonstrate how a thorough consideration of the variability inherent in clinical trials of novel therapies for acute viral infections can improve trial design. Methods and Findings We developed a clinical trial simulator to analyse the impact of three different types of variation on the outcome of a challenge study of influenza treatments for infected patients, including individual patient variability in the response to the drug, the variance of the measurement procedure, and the variance of the lower limit of quantification of endpoint measurements. In addition, we investigated the impact of protocol variation on clinical trial outcome. We found that the greatest source of variance was inter-individual variability in the natural course of infection. Running a larger phase II study can save up to $38 million, if an unlikely to succeed phase III trial is avoided. In addition, low-sensitivity viral load assays can lead to falsely negative trial outcomes. Conclusions Due to high inter-individual variability in natural infection, the most important variable in clinical trial design for challenge studies of potential novel influenza treatments is the number of participants. 100 participants are preferable over 50. Using more sensitive viral load assays increases the probability of a positive trial outcome, but may in some circumstances lead to false positive outcomes. Clinical trial simulations are powerful tools to identify the most important sources of variance in clinical trials and thereby help improve trial design. © 2016 Vegvari et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
BibTeX:
@article{Vegvari2016,
  author = {Vegvari, Carolin and Cauët, Emilie and Hadjichrysanthou, Christoforos and Lawrence, Emma and Weverling, Gerrit-Jan and De Wolf, Frank and Anderson, Roy M.},
  title = {Using clinical trial simulators to analyse the sources of variance in clinical trials of novel therapies for acute viral infections},
  journal = {PLoS ONE},
  year = {2016},
  volume = {11},
  number = {6},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1371/journal.pone.0156622}
}
Vegvari C, Hadjichrysanthou C, Cauët E, Lawrence E, Cori A, De Wolf F and Anderson RM (2016), "How can viral dynamics models inform endpoint measures in clinical trials of therapies for acute viral infections?", PLoS ONE. Vol. 11(7)
Abstract: Acute viral infections pose many practical challenges for the accurate assessment of the impact of novel therapies on viral growth and decay. Using the example of influenza A, we illustrate how the measurement of infection-related quantities that determine the dynamics of viral load within the human host, can inform investigators on the course and severity of infection and the efficacy of a novel treatment. We estimated the values of key infection-related quantities that determine the course of natural infection from viral load data, using Markov Chain Monte Carlo methods. The data were placebo group viral load measurements collected during volunteer challenge studies, conducted by Roche, as part of the oseltamivir trials. We calculated the values of the quantities for each patient and the correlations between the quantities, symptom severity and body temperature. The greatest variation among individuals occurred in the viral load peak and area under the viral load curve. Total symptom severity correlated positively with the basic reproductive number. The most sensitive endpoint for therapeutic trials with the goal to cure patients is the duration of infection. We suggest laboratory experiments to obtain more precise estimates of virological quantities that can supplement clinical endpoint measurements. © 2016 Vegvari et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
BibTeX:
@article{Vegvari2016a,
  author = {Vegvari, Carolin and Hadjichrysanthou, Christoforos and Cauët, Emilie and Lawrence, Emma and Cori, Anne and De Wolf, Frank and Anderson, Roy M.},
  title = {How can viral dynamics models inform endpoint measures in clinical trials of therapies for acute viral infections?},
  journal = {PLoS ONE},
  year = {2016},
  volume = {11},
  number = {7},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1371/journal.pone.0158237}
}
Wespes C, Hurtmans D, K Emmons L, Safieddine S, Clerbaux C, Edwards DP and Coheur P-F (2016), "Ozone variability in the troposphere and the stratosphere from the first 6 years of IASI observations (2008-2013)", Atmospheric Chemistry and Physics. Vol. 16(9), pp. 5721 – 5743.
Abstract: In this paper, we assess how daily ozone (O3) measurements from the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp-A platform can contribute to the analyses of the processes driving O3 variability in the troposphere and the stratosphere and, in the future, to the monitoring of long-term trends. The temporal evolution of O3 during the first 6 years of IASI (2008-2013) operation is investigated with multivariate regressions separately in four different layers (ground-300, 300-150, 150-25, 25-3ĝ€hPa), by adjusting to the daily time series averaged in 20° zonal bands, seasonal and linear trend terms along with important geophysical drivers of O3 variation (e.g. solar flux, quasi-biennial oscillation (QBO)). The regression model is shown to perform generally very well with a strong dominance of the annual harmonic terms and significant contributions from O3 drivers, in particular in the equatorial region where the QBO and the solar flux contribution dominate. More particularly, despite the short period of the IASI data set available up to now, two noticeable statistically significant apparent trends are inferred from the daily IASI measurements: a positive trend in the upper stratosphere (e.g. 1.74ĝ€±ĝ€0.77ĝ€DUĝ€yearĝ'1 between 30 and 50°ĝ€S), which is consistent with other studies suggesting a turnaround for stratospheric O3 recovery, and a negative trend in the troposphere at the mid-latitudes and high northern latitudes (e.g. ĝ'0.26ĝ€±ĝ€0.11ĝ€DUĝ€yearĝ'1 between 30 and 50°ĝ€N), especially during summer and probably linked to the impact of decreasing ozone precursor emissions. The impact of the high temporal sampling of IASI on the uncertainty in the determination of O3 trend has been further explored by performing multivariate regressions on IASI monthly averages and on ground-based Fourier transform infrared (FTIR) measurements. © Author(s) 2016. CC Attribution 3.0 License.
BibTeX:
@article{Wespes2016,
  author = {Wespes, Catherine and Hurtmans, Daniel and K Emmons, Louisa and Safieddine, Sarah and Clerbaux, Cathy and Edwards, David P. and Coheur, Pierre-François},
  title = {Ozone variability in the troposphere and the stratosphere from the first 6 years of IASI observations (2008-2013)},
  journal = {Atmospheric Chemistry and Physics},
  year = {2016},
  volume = {16},
  number = {9},
  pages = {5721 – 5743},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-16-5721-2016}
}
Whitburn S, VanDamme M, Clarisse L, Bauduin S, Heald C, Hadji-Lazaro J, Hurtmans D, Zondlo M, Clerbaux C and Coheur P-F (2016), "A flexible and robust neural network IASI-NH3 retrieval algorithm", Journal of Geophysical Research. Vol. 121(11), pp. 6581 – 6599.
Abstract: In this paper, we describe a new flexible and robust NH3 retrieval algorithm from measurements of the Infrared Atmospheric Sounding Interferometer (IASI). The method is based on the calculation of a spectral hyperspectral range index (HRI) and subsequent conversion to NH3 columns via a neural network. It is an extension of the method presented in VanDamme et al. (2014a) who used lookup tables (LUT) for the radiance-concentration conversion. The new method inherits the advantages of the LUT-based method while providing several significant improvements. These include the following: (1) Complete temperature and humidity vertical profiles can be accounted for. (2) Third-party NH3 vertical profile information can be used. (3) Reported positive biases of LUT retrieval are reduced, and finally (4) a full measurement uncertainty characterization is provided. A running theme in this study, related to item (2), is the importance of the assumed vertical NH3 profile. We demonstrate the advantages of allowing variable profile shapes in the retrieval. As an example, we analyze how the retrievals change when all NH3 is assumed to be confined to the boundary layer. We analyze different averaging procedures in use for NH3 in the literature, introduced to cope with the variable measurement sensitivity and derive global averaged distributions for the year 2013. A comparison with a GEOS-Chem modeled global distribution is also presented, showing a general good correspondence (within ±3×1015 molecules.cm-2) over most of the Northern Hemisphere. However, IASI finds mean columns about 1-1.5×1016 molecules.cm-2 (∼50-60%) lower than GEOS-Chem for India and the North China plain. © 2016. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Whitburn2016a,
  author = {Whitburn, S. and VanDamme, M. and Clarisse, L. and Bauduin, S. and Heald, C.L. and Hadji-Lazaro, J. and Hurtmans, D. and Zondlo, M.A. and Clerbaux, C. and Coheur, P.-F.},
  title = {A flexible and robust neural network IASI-NH3 retrieval algorithm},
  journal = {Journal of Geophysical Research},
  year = {2016},
  volume = {121},
  number = {11},
  pages = {6581 – 6599},
  note = {All Open Access, Green Open Access},
  doi = {10.1002/2016JD024828}
}
Whitburn S, VanDamme M, Clarisse L, Turquety S, Clerbaux C and Coheur P-F (2016), "Doubling of annual ammonia emissions from the peat fires in Indonesia during the 2015 El Niño", Geophysical Research Letters. Vol. 43(20), pp. 11,007 – 11,014.
Abstract: In the autumn of 2015, thousands of square kilometers of forest and peatlands in Indonesia went up in flames. Among the primary species emitted by fires, ammonia (NH3) is of special relevance for air quality. Here we derive daily and total NH3 emission fluxes over the affected area using satellite measurements for the years 2008–2015. The 2015 fires emitted an estimated 1.4–8.2 Tg of NH3 (with a maximum of 0.06–0.33 Tg d−1). On an annual basis, the 2015 NH3 emissions are a factor 2–3 larger than in the previous 7 years. We derive NH3 emission factors for peat soils, which are found to be 2.5–8 times lower than those used in the GFASv1.2 emission inventory but in excellent agreement with those reported in other recent studies. Finally, we estimate that 3.28 × 109 m3 peat soil was consumed during these 2015 fires, corresponding to an average burn depth of 39 cm. ©2016. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Whitburn2016,
  author = {Whitburn, S. and VanDamme, M. and Clarisse, L. and Turquety, S. and Clerbaux, C. and Coheur, P.-F.},
  title = {Doubling of annual ammonia emissions from the peat fires in Indonesia during the 2015 El Niño},
  journal = {Geophysical Research Letters},
  year = {2016},
  volume = {43},
  number = {20},
  pages = {11,007 – 11,014},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1002/2016GL070620}
}
Baldassarre G, Pozzoli L, Schmidt C, Unal A, Kindap T, Menzel W, Whitburn S, Coheur P-F, Kavgaci A and Kaiser J (2015), "Using SEVIRI fire observations to drive smoke plumes in the CMAQ air quality model: A case study over Antalya in 2008", Atmospheric Chemistry and Physics. Vol. 15(14), pp. 8539 – 8558.
Abstract: Among the atmospheric emission sources, wildfires are episodic events characterized by large spatial and temporal variability. Therefore, accurate information on gaseous and aerosol emissions from fires for specific regions and seasons is critical for air quality forecasts. The Spinning Enhanced Visible and Infrared Imager (SEVIRI) in geostationary orbit provides fire observations over Africa and the Mediterranean with a temporal resolution of 15 min. It thus resolves the complete fire life cycle and captures the fires' peak intensities, which is not possible in Moderate Resolution Imaging Spectroradiometer (MODIS) fire emission inventories like the Global Fire Assimilation System (GFAS). We evaluate two different operational fire radiative power (FRP) products derived from SEVIRI, by studying a large forest fire in Antalya, Turkey, in July-August 2008. The EUMETSAT Land Surface Analysis Satellite Applications Facility (LSA SAF) has higher FRP values during the fire episode than the Wildfire Automated Biomass Burning Algorithm (WF-ABBA). It is also in better agreement with the co-located, gridded MODIS FRP. Both products miss small fires that frequently occur in the region and are detected by MODIS. Emissions are derived from the FRP products. They are used along-side GFAS emissions in smoke plume simulations with the Weather Research and Forecasting (WRF) model and the Community Multiscale Air Quality (CMAQ) model. In comparisons with MODIS aerosol optical thickness (AOT) and Infrared Atmospheric Sounding Interferometer (IASI), CO and NH3 observations show that including the diurnal variability of fire emissions improves the spatial distribution and peak concentrations of the simulated smoke plumes associated with this large fire. They also show a large discrepancy between the currently available operational FRP products, with the LSA SAF being the most appropriate. © Author(s) 2015.
BibTeX:
@article{Baldassarre2015,
  author = {Baldassarre, G. and Pozzoli, L. and Schmidt, C.C. and Unal, A. and Kindap, T. and Menzel, W.P. and Whitburn, S. and Coheur, P.-F. and Kavgaci, A. and Kaiser, J.W.},
  title = {Using SEVIRI fire observations to drive smoke plumes in the CMAQ air quality model: A case study over Antalya in 2008},
  journal = {Atmospheric Chemistry and Physics},
  year = {2015},
  volume = {15},
  number = {14},
  pages = {8539 – 8558},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-15-8539-2015}
}
Baldassarre G, Pozzoli L, Schmidt C, Unal A, Kindap T, Menzel W, Whitburn S, Coheur P-F, Kavgaci A and Kaiser J (2015), "Using SEVIRI fire observations to drive smoke plumes in the CMAQ air quality model: The case of Antalya in 2008", Atmospheric Chemistry and Physics Discussions. Vol. 15(1), pp. 1 – 46.
Abstract: Among the atmospheric emission sources, wildfires are episodic events characterized by large spatial and temporal variability. Therefore, accurate information on fire gaseous and aerosol emissions for specific regions and seasons is critical for air quality forecasts. The Spinning Enhanced Visible and Infrared Imager (SEVIRI) in geostationary orbit provides fire observations over Africa and the Mediterranean with a unique temporal resolution of 15min. It thus resolves the complete fire life cycle and captures the fires' peak intensities, which is not possible in MODIS-based fire emission inventories like GFAS. We evaluate two different operational Fire Radiative Power (FRP) products derived from SEVIRI, by studying the case of a large forest fire in Antalya, Turkey, in July-August 2008. The EUMETSAT LSA SAF product has higher FRP values during the fire episode than the WF-ABBA product. It is also in better agreement with the colocated, gridded MODIS FRP. Both products miss small fires that frequently occur in the region and are detected by MODIS. Emissions are derived from the FRP products. They are used along-side GFAS emissions in smoke plume simulations with WRF and the Community Multiscale Air Quality model (CMAQ). Comparisons with MODIS AOT and IASI CO and NH3 observations show that including the diurnal variability of fire emissions improves the spatial distribution and peak concentrations of the simulated smoke plumes associated to the large fire. They also show a large discrepancy between the currently available operational FRP products, with the LSA SAF one being the most appropriate. © Author(s) 2015. CC Attribution 3.0 License.
BibTeX:
@article{Baldassarre2015a,
  author = {Baldassarre, G. and Pozzoli, L. and Schmidt, C.C. and Unal, A. and Kindap, T. and Menzel, W.P. and Whitburn, S. and Coheur, P.-F. and Kavgaci, A. and Kaiser, J.W.},
  title = {Using SEVIRI fire observations to drive smoke plumes in the CMAQ air quality model: The case of Antalya in 2008},
  journal = {Atmospheric Chemistry and Physics Discussions},
  year = {2015},
  volume = {15},
  number = {1},
  pages = {1 – 46},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.5194/acpd-15-1-2015}
}
Barré J, Gaubert B, Arellano AFJ, Worden HM, Edwards DP, Deeter MN, Anderson JL, Raeder K, Collins N, Tilmes S, Francis G, Clerbaux C, Emmons LK, Pfister GG, Coheur P-F and Hurtmans D (2015), "Assessing the impacts of assimilating IASI and MOPITT CO retrievals using CESM-CAM-chem and DART", Journal of Geophysical Research. Vol. 120(19), pp. 10501 – 10529.
Abstract: We show the results and evaluation with independent measurements from assimilating both MOPITT (Measurements Of Pollution In The Troposphere) and IASI (Infrared Atmospheric Sounding Interferometer) retrieved profiles into the Community Earth System Model (CESM). We used the Data Assimilation Research Testbed ensemble Kalman filter technique, with the full atmospheric chemistry CESM component Community Atmospheric Model with Chemistry. We first discuss the methodology and evaluation of the current data assimilation system with coupled meteorology and chemistry data assimilation. The different capabilities of MOPITT and IASI retrievals are highlighted, with particular attention to instrument vertical sensitivity and coverage and how these impact the analyses. MOPITT and IASI CO retrievals mostly constrain the CO fields close to the main anthropogenic, biogenic, and biomass burning CO sources. In the case of IASI CO assimilation, we also observe constraints on CO far from the sources. During the simulation time period (June and July 2008), CO assimilation of both instruments strongly improves the atmospheric CO state as compared to independent observations, with the higher spatial coverage of IASI providing better results on the global scale. However, the enhanced sensitivity of multispectral MOPITT observations to near surface CO over the main source regions provides synergistic effects at regional scales. © 2015. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Barre2015,
  author = {Barré, Jérôme and Gaubert, Benjamin and Arellano, Avelino F. J. and Worden, Helen M. and Edwards, David P. and Deeter, Merritt N. and Anderson, Jeffrey L. and Raeder, Kevin and Collins, Nancy and Tilmes, Simone and Francis, Gene and Clerbaux, Cathy and Emmons, Louisa K. and Pfister, Gabriele G. and Coheur, Pierre-François and Hurtmans, Daniel},
  title = {Assessing the impacts of assimilating IASI and MOPITT CO retrievals using CESM-CAM-chem and DART},
  journal = {Journal of Geophysical Research},
  year = {2015},
  volume = {120},
  number = {19},
  pages = {10501 – 10529},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1002/2015JD023467}
}
Berger G, Gelbcke M, Cauët E, Luhmer M, Nève J and Dufrasne F (2015), "Erratum:Corrigendum to "synthesis of 15N-labeled vicinal diamines through N-activated chiral aziridines: Tools for the NMR study of platinum-based anticancer compounds" (Tetrahedron Letters (2013) 54 (545-548) doi:10.1016/j.tetlet.2014.11.086))", Tetrahedron Letters. Vol. 56(2), pp. 485.
BibTeX:
@article{Berger2015,
  author = {Berger, Gilles and Gelbcke, Michel and Cauët, Emilie and Luhmer, Michel and Nève, Jean and Dufrasne, François},
  title = {Erratum:Corrigendum to "synthesis of 15N-labeled vicinal diamines through N-activated chiral aziridines: Tools for the NMR study of platinum-based anticancer compounds" (Tetrahedron Letters (2013) 54 (545-548) doi:10.1016/j.tetlet.2014.11.086))},
  journal = {Tetrahedron Letters},
  year = {2015},
  volume = {56},
  number = {2},
  pages = {485},
  doi = {10.1016/j.tetlet.2014.11.086}
}
Boichu M, Clarisse L, Péré J-C, Herbin H, Goloub P, Thieuleux F, Ducos F, Clerbaux C and Tanré D (2015), "Temporal variations of flux and altitude of sulfur dioxide emissions during volcanic eruptions: Implications for long-range dispersal of volcanic clouds", Atmospheric Chemistry and Physics. Vol. 15(14), pp. 8381 – 8400.
Abstract: Sulfur-rich degassing, which is mostly composed of sulfur dioxide (SO2), plays a major role in the overall impact of volcanism on the atmosphere and climate. The accurate assessment of this impact is currently hampered by the poor knowledge of volcanic SO2 emissions. Here, using an inversion procedure, we show how assimilating snapshots of the volcanic SO2 load derived from the Infrared Atmospheric Sounding Interferometer (IASI) allows for reconstructing both the flux and altitude of the SO2 emissions with an hourly resolution. For this purpose, the regional chemistry-transport model CHIMERE is used to describe the dispersion of SO2 when released in the atmosphere. As proof of concept, we study the 10 April 2011 eruption of the Etna volcano (Italy), which represents one of the few volcanoes instrumented on the ground for the continuous monitoring of SO2 degassing. We find that the SO2 flux time-series retrieved from satellite imagery using the inverse scheme is in agreement with ground observations during ash-poor phases of the eruption. However, large discrepancies are observed during the ash-rich paroxysmal phase as a result of enhanced plume opacity affecting ground-based ultraviolet (UV) spectroscopic retrievals. As a consequence, the SO2 emission rate derived from the ground is underestimated by almost one order of magnitude. Altitudes of the SO2 emissions predicted by the inverse scheme are validated against an RGB image of the Moderate Resolution Imaging Spectroradiometer (MODIS) capturing the near-source atmospheric pathways followed by Etna plumes, in combination with forward trajectories from the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. At a large distance from the source, modelled SO2 altitudes are compared with independent information on the volcanic cloud height. We find that the altitude predicted by the inverse scheme is in agreement with snapshots of the SO2 height retrieved from recent algorithms exploiting the high spectral resolution of IASI. The validity of the modelled SO2 altitude is further confirmed by the detection of a layer of particles at the same altitude by the spaceborne Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). Analysis of CALIOP colour and depolarization ratios suggests that these particles consist of sulfate aerosols formed from precursory volcanic SO2. The reconstruction of emission altitude, through inversion procedures which assimilate volcanic SO2 column amounts, requires specific meteorological conditions, especially sufficient wind shear so that gas parcels emitted at different altitudes follow distinct trajectories. We consequently explore the possibility and limits of assimilating in inverse schemes infrared (IR) imagery of the volcanic SO2 cloud altitude which will render the inversion procedure independent of the wind shear prerequisite. © Author(s) 2015.
BibTeX:
@article{Boichu2015,
  author = {Boichu, M. and Clarisse, L. and Péré, J.-C. and Herbin, H. and Goloub, P. and Thieuleux, F. and Ducos, F. and Clerbaux, C. and Tanré, D.},
  title = {Temporal variations of flux and altitude of sulfur dioxide emissions during volcanic eruptions: Implications for long-range dispersal of volcanic clouds},
  journal = {Atmospheric Chemistry and Physics},
  year = {2015},
  volume = {15},
  number = {14},
  pages = {8381 – 8400},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-15-8381-2015}
}
Bonne J-L, Steen-Larsen HC, Risi C, Werner M, Sodemann H, Lacour J-L, Fettweis X, Cesana G, Delmotte M, Cattani O, Vallelonga P, Kjær HA, Clerbaux C, Sveinbjörnsdóttir ÁE and Masson-Delmotte V (2015), "The summer 2012 Greenland heat wave: In situ and remote sensing observations of water vapor isotopic composition during an atmospheric river event", Journal of Geophysical Research. Vol. 120(7), pp. 2970 – 2989.
Abstract: During 7-12 July 2012, extreme moist and warm conditions occurred over Greenland, leading to widespread surface melt. To investigate the physical processes during the atmospheric moisture transport of this event, we study the water vapor isotopic composition using surface in situ observations in Bermuda Island, South Greenland coast (Ivittuut), and northwest Greenland ice sheet (NEEM), as well as remote sensing observations (Infrared Atmospheric Sounding Interferometer (IASI) instrument on board MetOp-A), depicting propagation of similar surface and midtropospheric humidity and δD signals. Simulations using Lagrangian moisture source diagnostic and water tagging in a regional model showed that Greenland was affected by an atmospheric river transporting moisture from the western subtropical North Atlantic Ocean, which is coherent with observations of snow pit impurities deposited at NEEM. At Ivittuut, surface air temperature, humidity, and δD increases are observed. At NEEM, similar temperature increase is associated with a large and long-lasting  100‰δD enrichment and  15‰ deuterium excess decrease, thereby reaching Ivittuut level. We assess the simulation of this event in two isotope-enabled atmospheric general circulation models (LMDz-iso and ECHAM5-wiso). LMDz-iso correctly captures the timing of propagation for this event identified in IASI data but depict too gradual variations when compared to surface data. Both models reproduce the surface meteorological and isotopic values during the event but underestimate the background deuterium excess at NEEM. Cloud liquid water content parametrization in LMDz-iso poorly impacts the vapor isotopic composition. Our data demonstrate that during this atmospheric river event the deuterium excess signal is conserved from the moisture source to northwest Greenland. © 2015. American Geophysical Union. All Rights Reserved.
BibTeX:
@article{Bonne2015,
  author = {Bonne, Jean-Louis and Steen-Larsen, Hans Christian and Risi, Camille and Werner, Martin and Sodemann, Harald and Lacour, Jean-Lionel and Fettweis, Xavier and Cesana, Grégory and Delmotte, Marc and Cattani, Olivier and Vallelonga, Paul and Kjær, Helle Astrid and Clerbaux, Cathy and Sveinbjörnsdóttir, Árny Erla and Masson-Delmotte, Valérie},
  title = {The summer 2012 Greenland heat wave: In situ and remote sensing observations of water vapor isotopic composition during an atmospheric river event},
  journal = {Journal of Geophysical Research},
  year = {2015},
  volume = {120},
  number = {7},
  pages = {2970 – 2989},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1002/2014JD022602}
}
Clerbaux C, Hadji-Lazaro J, Turquety S, George M, Boynard A, Pommier M, Safieddine S, Coheur P-F, Hurtmans D, Clarisse L and VanDamme M (2015), "Tracking pollutants from space: Eight years of IASI satellite observation", Comptes Rendus - Geoscience. Vol. 347(3), pp. 134 – 144.
Abstract: The IASI mission flying onboard the MetOp satellites has been providing global observations of the air composition twice a day since 2007. From the atmospheric spectra recorded by the instruments in the thermal infrared spectral range, concentrations of a series of trace gases can be monitored, enhanced levels of pollution can be detected, and particle types can be determined to some extent. This paper recalls the historical context for the IASI remote sensor, reviews its capability to observe some key species for global and regional pollution monitoring, and reports on information services that benefit from the mission. © 2015 Academie des sciences
BibTeX:
@article{Clerbaux2015,
  author = {Clerbaux, Cathy and Hadji-Lazaro, Juliette and Turquety, Solène and George, Maya and Boynard, Anne and Pommier, Matthieu and Safieddine, Sarah and Coheur, Pierre-François and Hurtmans, Daniel and Clarisse, Lieven and VanDamme, Martin},
  title = {Tracking pollutants from space: Eight years of IASI satellite observation},
  journal = {Comptes Rendus - Geoscience},
  year = {2015},
  volume = {347},
  number = {3},
  pages = {134 – 144},
  note = {All Open Access, Bronze Open Access, Green Open Access},
  doi = {10.1016/j.crte.2015.06.001}
}
Dammers E, Vigouroux C, Palm M, Mahieu E, Warneke T, Smale D, Langerock B, Franco B, VanDamme M, Schaap M, Notholt J and Erisman J (2015), "Retrieval of ammonia from ground-based FTIR solar spectra", Atmospheric Chemistry and Physics. Vol. 15(22), pp. 12789 – 12803.
Abstract: We present a retrieval method for ammonia (NH3) total columns from ground-based Fourier transform infrared (FTIR) observations. Observations from Bremen (53.10° N, 8.85° E), Lauder (45.04° S, 169.68° E), Reúnion (20.9° S, 55.50° E) and Jungfraujoch (46.55° N, 7.98° E) were used to illustrate the capabilities of the method. NH3 mean total columns ranging 3 orders of magnitude were obtained, with higher values at Bremen (mean of 13.47 × 1015 molecules cm-2) and lower values at Jungfraujoch (mean of 0.18 × 1015 molecules cm-2). In conditions with high surface concentrations of ammonia, as in Bremen, it is possible to retrieve information on the vertical gradient, as two layers can be distinguished. The retrieval there is most sensitive to ammonia in the planetary boundary layer, where the trace gas concentration is highest. For conditions with low concentrations, only the total column can be retrieved. Combining the systematic and random errors we have a mean total error of 26 % for all spectra measured at Bremen (number of spectra (N)= 554), 30 % for all spectra from Lauder (N = 2412), 25 % for spectra from Reúnion (N = 1262) and 34 % for spectra measured at Jungfraujoch (N = 2702). The error is dominated by the systematic uncertainties in the spectroscopy parameters. Station-specific seasonal cycles were found to be consistent with known seasonal cycles of the dominant ammonia sources in the station surroundings. The developed retrieval methodology from FTIR instruments provides a new way of obtaining highly time-resolved measurements of ammonia burdens. FTIR-NH3 observations will be useful for understanding the dynamics of ammonia concentrations in the atmosphere and for satellite and model validation. It will also provide additional information to constrain the global ammonia budget. © 2015 Author(s).
BibTeX:
@article{Dammers2015,
  author = {Dammers, E. and Vigouroux, C. and Palm, M. and Mahieu, E. and Warneke, T. and Smale, D. and Langerock, B. and Franco, B. and VanDamme, M. and Schaap, M. and Notholt, J. and Erisman, J.W.},
  title = {Retrieval of ammonia from ground-based FTIR solar spectra},
  journal = {Atmospheric Chemistry and Physics},
  year = {2015},
  volume = {15},
  number = {22},
  pages = {12789 – 12803},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-15-12789-2015}
}
Dammers E, Vigouroux C, Palm M, Mahieu E, Warneke T, Smale D, Langerock B, Franco B, VanDamme M, Schaap M, Notholt J and Erisman J (2015), "Retrieval of ammonia from ground-based FTIR solar spectra", Atmospheric Chemistry and Physics Discussions. Vol. 15(16), pp. 23279 – 23315.
Abstract: We present a retrieval method for ammonia (NH3) total columns from ground-based Fourier Transform InfraRed (FTIR) observations. Observations from Bremen (53.10° N, 8.85° E), Lauder (45.04° S, 169.68° E), Reunion (20.9° S, 55.50 ° E) and Jungfraujoch (46.55° N, 7.98° E) were used to illustrate the capabilities of the method. NH3 mean total columns ranging three orders of magnitude were obtained with higher values at Bremen (mean of 13.47 × 1015 molecules cm-2) to the lower values at Jungfraujoch (mean of 0.18 × 1015 molecules cm-2). In conditions with high surface concentrations of ammonia, as in Bremen, it is possible to retrieve information on the vertical gradient as two layers can be discriminated. The retrieval there is most sensitive to ammonia in the planetary boundary layer, where the trace gas concentration is highest. For conditions with low concentrations only the total column can be retrieved. Combining the systematic and random errors we have a mean total error of 26 % for all spectra measured at Bremen (Number of spectra (N) Combining double low line 554), 30 % for all spectra from Lauder (N Combining double low line2412), 25 % for spectra from Reunion (N Combining double low line1262) and 34 % for spectra measured at Jungfraujoch (N Combining double low line2702). The error is dominated by the systematic uncertainties in the spectroscopy parameters. Station specific seasonal cycles were found to be consistent with known seasonal cycles of the dominant ammonia sources in the station surroundings. The developed retrieval methodology from FTIR-instruments provides a new way to obtain highly time-resolved measurements of ammonia burdens. FTIR-NH3 observations will be useful for understanding the dynamics of ammonia concentrations in the atmosphere and for satellite and model validation. It will also provide additional information to constrain the global ammonia budget. © Author(s) 2015.
BibTeX:
@article{Dammers2015a,
  author = {Dammers, E. and Vigouroux, C. and Palm, M. and Mahieu, E. and Warneke, T. and Smale, D. and Langerock, B. and Franco, B. and VanDamme, M. and Schaap, M. and Notholt, J. and Erisman, J.W.},
  title = {Retrieval of ammonia from ground-based FTIR solar spectra},
  journal = {Atmospheric Chemistry and Physics Discussions},
  year = {2015},
  volume = {15},
  number = {16},
  pages = {23279 – 23315},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.5194/acpd-15-23279-2015}
}
Doniki S, Hurtmans D, Clarisse L, Clerbaux C, Worden H, Bowman K and Coheur P-F (2015), "Instantaneous longwave radiative impact of ozone: An application on IASI/MetOp observations", Atmospheric Chemistry and Physics. Vol. 15(22), pp. 12971 – 12987.
Abstract: Ozone is an important greenhouse gas in terms of anthropogenic radiative forcing (RF). RF calculations for ozone were until recently entirely model based, and significant discrepancies were reported due to different model characteristics. However, new instantaneous radiative kernels (IRKs) calculated from hyperspectral thermal IR satellites have been able to help adjudicate between different climate model RF calculations. IRKs are defined as the sensitivity of the outgoing longwave radiation (OLR) flux with respect to the ozone vertical distribution in the full 9.6 μm band. Previous methods applied to measurements from the Tropospheric Emission Spectrometer (TES) on Aura rely on an anisotropy approximation for the angular integration. In this paper, we present a more accurate but more computationally expensive method to calculate these kernels. The method of direct integration is based on similar principles to the anisotropy approximation, but it deals more precisely with the integration of the Jacobians. We describe both methods and highlight their differences with respect to the IRKs and the ozone longwave radiative effect (LWRE), i.e., the radiative impact in OLR due to absorption by ozone, for both tropospheric and total columns, from measurements of the Infrared Atmospheric Sounding Interferometer (IASI) onboard MetOp-A. Biases between the two methods vary from -25 to +20 % for the LWRE, depending on the viewing angle. These biases point to the inadequacy of the anisotropy method, especially at nadir, suggesting that the TES-derived LWREs are biased low by around 25 % and that chemistry-climate model OLR biases with respect to TES are underestimated. In this paper we also exploit the sampling performance of IASI to obtain first daily global distributions of the LWRE, for 12 days (the 15th of each month) in 2011, calculated with the direct integration method. We show that the temporal variation of global and latitudinal averages of the LWRE shows patterns which are controlled by changes in the surface temperature and ozone variation due to specific processes, such as the ozone hole in the polar regions and stratospheric intrusions into the troposphere. © Author(s) 2015.
BibTeX:
@article{Doniki2015,
  author = {Doniki, S. and Hurtmans, D. and Clarisse, L. and Clerbaux, C. and Worden, H.M. and Bowman, K.W. and Coheur, P.-F.},
  title = {Instantaneous longwave radiative impact of ozone: An application on IASI/MetOp observations},
  journal = {Atmospheric Chemistry and Physics},
  year = {2015},
  volume = {15},
  number = {22},
  pages = {12971 – 12987},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-15-12971-2015}
}
Duflot V, Wespes C, Clarisse L, Hurtmans D, Ngadi Y, Jones N, Paton-Walsh C, Hadji-Lazaro J, Vigouroux C, De Mazière M, Metzger J-M, Mahieu E, Servais C, Hase F, Schneider M, Clerbaux C and Coheur P-F (2015), "Acetylene (C2H2) and hydrogen cyanide (HCN) from IASI satellite observations: Global distributions, validation, and comparison with model", Atmospheric Chemistry and Physics. Vol. 15(18), pp. 10509 – 10527.
Abstract: We present global distributions of C2H2 and hydrogen cyanide (HCN) total columns derived from the Infrared Atmospheric Sounding Interferometer (IASI) for the years 2008-2010. These distributions are obtained with a fast method allowing to retrieve C2H2 abundance globally with a 5 % precision and HCN abundance in the tropical (subtropical) belt with a 10 % (25 %) precision. IASI data are compared for validation purposes with ground-based Fourier transform infrared (FTIR) spectrometer measurements at four selected stations. We show that there is an overall agreement between the ground-based and space measurements with correlation coefficients for daily mean measurements ranging from 0.28 to 0.81, depending on the site. Global C2H2 and subtropical HCN abundances retrieved from IASI spectra show the expected seasonality linked to variations in the anthropogenic emissions and seasonal biomass burning activity, as well as exceptional events, and are in good agreement with previous spaceborne studies. Total columns simulated by the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4) are compared to the ground-based FTIR measurements at the four selected stations. The model is able to capture the seasonality in the two species in most of the cases, with correlation coefficients for daily mean measurements ranging from 0.50 to 0.86, depending on the site. IASI measurements are also compared to the distributions from MOZART-4. Seasonal cycles observed from satellite data are reasonably well reproduced by the model with correlation coefficients ranging from g'0.31 to 0.93 for C2H2 daily means, and from 0.09 to 0.86 for HCN daily means, depending on the considered region. However, the anthropogenic (biomass burning) emissions used in the model seem to be overestimated (underestimated), and a negative global mean bias of 1 % (16 %) of the model relative to the satellite observations was found for C2H2 (HCN). © Author(s) 2015.
BibTeX:
@article{Duflot2015,
  author = {Duflot, V. and Wespes, C. and Clarisse, L. and Hurtmans, D. and Ngadi, Y. and Jones, N. and Paton-Walsh, C. and Hadji-Lazaro, J. and Vigouroux, C. and De Mazière, M. and Metzger, J.-M. and Mahieu, E. and Servais, C. and Hase, F. and Schneider, M. and Clerbaux, C. and Coheur, P.-F.},
  title = {Acetylene (C2H2) and hydrogen cyanide (HCN) from IASI satellite observations: Global distributions, validation, and comparison with model},
  journal = {Atmospheric Chemistry and Physics},
  year = {2015},
  volume = {15},
  number = {18},
  pages = {10509 – 10527},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-15-10509-2015}
}
Erisman JW, Dammers E, VanDamme M, Soudzilovskaia N and Schaap M (2015), "Trends in EU nitrogen deposition and impacts on ecosystems", EM: Air and Waste Management Association's Magazine for Environmental Managers. Vol. 65(September), pp. 31 – 35.
Abstract: An overview of the achievements and the current state of knowledge on reactive nitrogen in Europe, focusing on deposition, critical load exceedances, and modeled and measured trends.
BibTeX:
@article{Erisman2015,
  author = {Erisman, Jan Willem and Dammers, Enrico and VanDamme, Martin and Soudzilovskaia, Nadejda and Schaap, Martijn},
  title = {Trends in EU nitrogen deposition and impacts on ecosystems},
  journal = {EM: Air and Waste Management Association's Magazine for Environmental Managers},
  year = {2015},
  volume = {65},
  number = {September},
  pages = {31 – 35}
}
Földes T, Lauzin C, Vanfleteren T, Herman M, Liévin J and Didriche K (2015), "High-resolution, near-infrared CW-CRDS, and ab initio investigations of N2O-HDO", Molecular Physics. Vol. 113(5), pp. 473 – 482.
Abstract: We have investigated the N2O-HDO molecular complex using ab initio calculations at the CCSD(T)-F12a/aug-cc-pVTZ level of theory and using cavity ring-down spectroscopy to probe an HDO/N2O/Ar supersonic jet around 1.58 m. A single a-type vibrational band was observed, 13 cm-1 redshifted compared to the OH+OD excited band in HDO, and 173 vibration-rotation lines were assigned (Trot ≈ 20 K). A weighted fit of existing microwave and present near infrared (NIR) data was achieved using a standard Watson's Hamiltonian (σ = 1.26), producing ground and excited states rotational constants. The comparison of the former with those calculated ab initio suggests a planar geometry in which the OD rather than the OH bond in water is almost parallel to NNO. The equilibrium geometry and dissociation energy (De = -11.7 kJ/mol) of the water-nitrous oxide complex were calculated. The calculations further demonstrate and allow characterising another minimum, 404 cm-1 (ΔE0) higher in energy. Harmonic vibrational frequencies and dissociation energies, D0, were calculated for various conformers and isotopic forms of the complex, in both minima. The absence of N2O-D2O from dedicated NIR experiments is reported and discussed. © 2014 Taylor & Francis.
BibTeX:
@article{Foeldes2015,
  author = {Földes, T. and Lauzin, C. and Vanfleteren, T. and Herman, M. and Liévin, J. and Didriche, K.},
  title = {High-resolution, near-infrared CW-CRDS, and ab initio investigations of N2O-HDO},
  journal = {Molecular Physics},
  year = {2015},
  volume = {113},
  number = {5},
  pages = {473 – 482},
  doi = {10.1080/00268976.2014.953611}
}
Franco B, Bader W, Toon G, Bray C, Perrin A, Fischer E, Sudo K, Boone C, Bovy B, Lejeune B, Servais C and Mahieu E (2015), "Retrieval of ethane from ground-based FTIR solar spectra using improved spectroscopy: Recent burden increase above Jungfraujoch", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 160, pp. 36 – 49.
Abstract: An improved spectroscopy is used to implement and optimize the retrieval strategy of ethane (C2H6) from ground-based Fourier Transform Infrared (FTIR) solar spectra recorded at the high-altitude station of Jungfraujoch (Swiss Alps, 46.5°N, 8.0°E, 3580m a.s.l.). The improved spectroscopic parameters include C2H6 pseudo-lines in the 2720-3100cm-1 range and updated line parameters for methyl chloride and ozone. These improved spectroscopic parameters allow for substantial reduction of the fitting residuals as well as enhanced information content. They also contribute to limiting oscillations responsible for ungeophysical negative mixing ratio profiles. This strategy has been successfully applied to the Jungfraujoch solar spectra available from 1994 onwards. The resulting time series is compared with C2H6 total columns simulated by the state-of-the-art chemical transport model GEOS-Chem. Despite very consistent seasonal cycles between both data sets, a negative systematic bias relative to the FTIR observations suggests that C2H6 emissions are underestimated in the current inventories implemented in GEOS-Chem. Finally, C2H6 trends are derived from the FTIR time series, revealing a statistically-significant sharp increase of the C2H6 burden in the remote atmosphere above Jungfraujoch since 2009. Evaluating cause of this change in the C2H6 burden, which may be related to the recent massive growth of shale gas exploitation in North America, is of primary importance for atmospheric composition and air quality in the Northern Hemisphere. © 2015 Elsevier Ltd.
BibTeX:
@article{Franco2015,
  author = {Franco, B. and Bader, W. and Toon, G.C. and Bray, C. and Perrin, A. and Fischer, E.V. and Sudo, K. and Boone, C.D. and Bovy, B. and Lejeune, B. and Servais, C. and Mahieu, E.},
  title = {Retrieval of ethane from ground-based FTIR solar spectra using improved spectroscopy: Recent burden increase above Jungfraujoch},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2015},
  volume = {160},
  pages = {36 – 49},
  doi = {10.1016/j.jqsrt.2015.03.017}
}
Franco B, Hendrick F, vanRoozendael M, Müller J-F, Stavrakou T, Marais E, Bovy B, Bader W, Fayt C, Hermans C, Lejeune B, Pinardi G, Servais C and Mahieu E (2015), "Retrievals of formaldehyde from ground-based FTIR and MAX-DOAS observations at the Jungfraujoch station and comparisons with GEOS-Chem and IMAGES model simulations", Atmospheric Measurement Techniques. Vol. 8(4), pp. 1733 – 1756.
Abstract: As an ubiquitous product of the oxidation of many volatile organic compounds (VOCs), formaldehyde (HCHO) plays a key role as a short-lived and reactive intermediate in the atmospheric photo-oxidation pathways leading to the formation of tropospheric ozone and secondary organic aerosols. In this study, HCHO profiles have been successfully retrieved from ground-based Fourier transform infrared (FTIR) solar spectra and UV-visible Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) scans recorded during the July 2010&ndash;December 2012 time period at the Jungfraujoch station (Swiss Alps, 46.5&deg; N, 8.0&deg; E, 3580 m a.s.l.). Analysis of the retrieved products has revealed different vertical sensitivity between both remote sensing techniques. Furthermore, HCHO amounts simulated by two state-of-the-art chemical transport models (CTMs), GEOS-Chem and IMAGES v2, have been compared to FTIR total columns and MAX-DOAS 3.6&ndash;8 km partial columns, accounting for the respective vertical resolution of each ground-based instrument. Using the CTM outputs as the intermediate, FTIR and MAX-DOAS retrievals have shown consistent seasonal modulations of HCHO throughout the investigated period, characterized by summertime maximum and wintertime minimum. Such comparisons have also highlighted that FTIR and MAX-DOAS provide complementary products for the HCHO retrieval above the Jungfraujoch station. Finally, tests have revealed that the updated IR parameters from the HITRAN 2012 database have a cumulative effect and significantly decrease the retrieved HCHO columns with respect to the use of the HITRAN 2008 compilation. © Author(s) 2015.
BibTeX:
@article{Franco2015a,
  author = {Franco, B. and Hendrick, F. and vanRoozendael, M. and Müller, J.-F. and Stavrakou, T. and Marais, E.A. and Bovy, B. and Bader, W. and Fayt, C. and Hermans, C. and Lejeune, B. and Pinardi, G. and Servais, C. and Mahieu, E.},
  title = {Retrievals of formaldehyde from ground-based FTIR and MAX-DOAS observations at the Jungfraujoch station and comparisons with GEOS-Chem and IMAGES model simulations},
  journal = {Atmospheric Measurement Techniques},
  year = {2015},
  volume = {8},
  number = {4},
  pages = {1733 – 1756},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-8-1733-2015}
}
George M, Clerbaux C, Bouarar I, Coheur P-F, Deeter M, Edwards D, Francis G, Gille J, Hadji-Lazaro J, Hurtmans D, Inness A, Mao D and Worden H (2015), "An examination of the long-term CO records from MOPITT and IASI: Comparison of retrieval methodology", Atmospheric Measurement Techniques. Vol. 8(10), pp. 4313 – 4328.
Abstract: Carbon monoxide (CO) is a key atmospheric compound that can be remotely sensed by satellite on the global scale. Fifteen years of continuous observations are now available from the MOPITT/Terra mission (2000 to present). Another 15 and more years of observations will be provided by the IASI/MetOp instrument series (2007-2023 >). In order to study long-term variability and trends, a homogeneous record is required, which is not straightforward as the retrieved quantities are instrument and processing dependent. The present study aims at evaluating the consistency between the CO products derived from the MOPITT and IASI missions, both for total columns and vertical profiles, during a 6-year overlap period (2008-2013). The analysis is performed by first comparing the available 2013 versions of the retrieval algorithms (v5T for MOPITT and v20100815 for IASI), and second using a dedicated reprocessing of MOPITT CO profiles and columns using the same a priori information as the IASI product. MOPITT total columns are generally slightly higher over land (bias ranging from 0 to 13 %) than IASI data. When IASI and MOPITT data are retrieved with the same a priori constraints, correlation coefficients are slightly improved. Large discrepancies (total column bias over 15 %) observed in the Northern Hemisphere during the winter months are reduced by a factor of 2 to 2.5. The detailed analysis of retrieved vertical profiles compared with collocated aircraft data from the MOZAIC-IAGOS network, illustrates the advantages and disadvantages of a constant vs. a variable a priori. On one hand, MOPITT agrees better with the aircraft profiles for observations with persisting high levels of CO throughout the year due to pollution or seasonal fire activity (because the climatology-based a priori is supposed to be closer to the real atmospheric state). On the other hand, IASI performs better when unexpected events leading to high levels of CO occur, due to a larger variability associated with the a priori. © 2015 Author(s).
BibTeX:
@article{George2015,
  author = {George, M. and Clerbaux, C. and Bouarar, I. and Coheur, P.-F. and Deeter, M.N. and Edwards, D.P. and Francis, G. and Gille, J.C. and Hadji-Lazaro, J. and Hurtmans, D. and Inness, A. and Mao, D. and Worden, H.M.},
  title = {An examination of the long-term CO records from MOPITT and IASI: Comparison of retrieval methodology},
  journal = {Atmospheric Measurement Techniques},
  year = {2015},
  volume = {8},
  number = {10},
  pages = {4313 – 4328},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-8-4313-2015}
}
Golebiowski D, Földes T, Vanfleteren T, Herman M and Perrin A (2015), "Complementary cavity-enhanced spectrometers to investigate the OH + CH combination band in trans -formic acid", Journal of Chemical Physics. Vol. 143(1)
Abstract: We have used continuous-wave cavity ring-down and femto-Fourier transform-cavity-enhanced absorption spectrometers to record the spectrum of the OH-stretching + CH-stretching (ν1 + ν2) combination band in trans-formic acid, with origin close to 6507 cm-1. They, respectively, allowed resolving and simplifying the rotational structure of the band near its origin under jet-cooled conditions (Trot = 10 K) and highlighting the overview of the band under room temperature conditions. The stronger B-type and weaker A-type subbands close to the band origin could be assigned, as well as the main B-type Q branches. The high-resolution analysis was hindered by numerous, severe perturbations. Rotational constants are reported with, however, limited physical meaning. The ν1 + ν2 transition moment is estimated from relative intensities to be 24°away from the principal b-axis of inertia. © 2015 AIP Publishing LLC.
BibTeX:
@article{Golebiowski2015,
  author = {Golebiowski, D. and Földes, T. and Vanfleteren, T. and Herman, M. and Perrin, A.},
  title = {Complementary cavity-enhanced spectrometers to investigate the OH + CH combination band in trans -formic acid},
  journal = {Journal of Chemical Physics},
  year = {2015},
  volume = {143},
  number = {1},
  doi = {10.1063/1.4923256}
}
Jecko T, Sutcliffe BT and Woolley RG (2015), "On factorization of molecular wavefunctions", Journal of Physics A: Mathematical and Theoretical. Vol. 48(44)
Abstract: Recently there has been a renewed interest in the chemical physics literature of factorization of the position representation eigenfunctions φ of the molecular Schrödinger equation as originally proposed by Hunter in the 1970s. The idea is to represent φ in the form φχ where χ is purely a function of the nuclear coordinates, while φ must depend on both electron and nuclear position variables in the problem. This is a generalization of the approximate factorization originally proposed by Born and Oppenheimer, the hope being that an 'exact' representation of φ can be achieved in this form with φ and χ interpretable as 'electronic' and 'nuclear' wavefunctions respectively. We offer a mathematical analysis of these proposals that identifies ambiguities stemming mainly from the singularities in the Coulomb potential energy. © 2015 IOP Publishing Ltd.
BibTeX:
@article{Jecko2015,
  author = {Jecko, Thierry and Sutcliffe, Brian T. and Woolley, R. Guy},
  title = {On factorization of molecular wavefunctions},
  journal = {Journal of Physics A: Mathematical and Theoretical},
  year = {2015},
  volume = {48},
  number = {44},
  note = {All Open Access, Green Open Access},
  doi = {10.1088/1751-8113/48/44/445201}
}
Lacour J-L, Clarisse L, Worden J, Schneider M, Barthlott S, Hase F, Risi C, Clerbaux C, Hurtmans D and Coheur P-F (2015), "Cross-validation of IASI/MetOp derived tropospheric δd with TES and ground-based FTIR observations", Atmospheric Measurement Techniques. Vol. 8(3), pp. 1447 – 1466.
Abstract: The Infrared Atmospheric Sounding Interferometer (IASI) flying onboard MetOpA and MetOpB is able to capture fine isotopic variations of the HDO to H2O ratio (δD) in the troposphere. Such observations at the high spatio-temporal resolution of the sounder are of great interest to improve our understanding of the mechanisms controlling humidity in the troposphere. In this study we aim to empirically assess the validity of our error estimation previously evaluated theoretically. To achieve this, we compare IASI δD retrieved profiles with other available profiles of δD, from the TES infrared sounder onboard AURA and from three ground-based FTIR stations produced within the MUSICA project: the NDACC (Network for the Detection of Atmospheric Composition Change) sites Kiruna and Izaña, and the TCCON site Karlsruhe, which in addition to near-infrared TCCON spectra also records mid-infrared spectra. We describe the achievable level of agreement between the different retrievals and show that these theoretical errors are in good agreement with empirical differences. The comparisons are made at different locations from tropical to Arctic latitudes, above sea and above land. Generally IASI and TES are similarly sensitive to δD in the free troposphere which allows one to compare their measurements directly. At tropical latitudes where IASI's sensitivity is lower than that of TES, we show that the agreement improves when taking into account the sensitivity of IASI in the TES retrieval. For the comparison IASI-FTIR only direct comparisons are performed because the sensitivity profiles of the two observing systems do not allow to take into account their differences of sensitivity. We identify a quasi negligible bias in the free troposphere (-3 ‰) between IASI retrieved δD with the TES, which are bias corrected, but important with the ground-based FTIR reaching -47 ‰. We also suggest that model-satellite observation comparisons could be optimized with IASI thanks to its high spatial and temporal sampling. © Author(s) 2015.
BibTeX:
@article{Lacour2015,
  author = {Lacour, J.-L. and Clarisse, L. and Worden, J. and Schneider, M. and Barthlott, S. and Hase, F. and Risi, C. and Clerbaux, C. and Hurtmans, D. and Coheur, P.-F.},
  title = {Cross-validation of IASI/MetOp derived tropospheric δd with TES and ground-based FTIR observations},
  journal = {Atmospheric Measurement Techniques},
  year = {2015},
  volume = {8},
  number = {3},
  pages = {1447 – 1466},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/amt-8-1447-2015}
}
Lamarre N, Gans B, Alcaraz C, De Miranda BC, Guillemin J-C, Broquier M, Liévin J and Boyé-Péronne S (2015), "Vibronic structure of the 2Π u ground electronic state of dicyanoacetylene cation revisited by PFI-ZEKE photoelectron spectroscopy and ab initio calculations", Molecular Physics. Vol. 113(24), pp. 3946 – 3954.
Abstract: The X+ 2Πu ← X1Σ+ g transition of dicyanoacetylene has been recorded for the first time using pulsed-field-ionisation zero-kinetic-energy photoelectron spectroscopy. The analysis of the photoelectron spectrum allowed an accurate determination of the adiabatic ionisation potential of C4N2 (Ei, ad./hc = 95,479 ± 2 cm-1) and a description of the vibrational structure of the electronic ground state of the cation which is affected by the Renner-Teller effect and the spin-orbit interaction. The spin-orbit coupling constant was measured as -52 ± 2 cm-1. These results are supported by ab initio calculations performed at the complete active space self-consistent field and second-order perturbation theory levels of theory, with extrapolation to the complete basis set limit. © 2015 Taylor and Francis.
BibTeX:
@article{Lamarre2015,
  author = {Lamarre, Nicolas and Gans, Bérenger and Alcaraz, Christian and De Miranda, Barbara Cunha and Guillemin, Jean-Claude and Broquier, Michel and Liévin, Jacques and Boyé-Péronne, Séverine},
  title = {Vibronic structure of the 2Π u ground electronic state of dicyanoacetylene cation revisited by PFI-ZEKE photoelectron spectroscopy and ab initio calculations},
  journal = {Molecular Physics},
  year = {2015},
  volume = {113},
  number = {24},
  pages = {3946 – 3954},
  doi = {10.1080/00268976.2015.1075074}
}
Lamouroux J, Régalia L, Thomas X, VanderAuwera J, Gamache R and Hartmann J-M (2015), "CO2 line-mixing database and software update and its tests in the 2.1μm and 4.3μm regions", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 151, pp. 88 – 96.
Abstract: An update of the former version of the database and software for the calculation of CO2-air absorption coefficients taking line-mixing into account [Lamouroux et al. J Quant Spectrosc Radiat Transf 2010;111:2321] is described. In this new edition, the data sets were constructed using parameters from the 2012 version of the HITRAN database and recent measurements of line-shape parameters. Among other improvements, speed-dependent profiles can now be used if line-mixing is treated within the first order approximation. This new package is tested using laboratory spectra measured in the 2.1μm and 4.3μm spectral regions for various pressures, temperatures and CO2 concentration conditions. Despite improvements at 4.3μm at room temperature, the conclusions on the quality of this update are more ambiguous at low temperature and in the 2.1μm region. Further tests using laboratory and atmospheric spectra are thus required for the evaluation of the performances of this updated package. © 2014 Elsevier Ltd.
BibTeX:
@article{Lamouroux2015,
  author = {Lamouroux, J. and Régalia, L. and Thomas, X. and VanderAuwera, J. and Gamache, R.R. and Hartmann, J.-M.},
  title = {CO2 line-mixing database and software update and its tests in the 2.1μm and 4.3μm regions},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2015},
  volume = {151},
  pages = {88 – 96},
  doi = {10.1016/j.jqsrt.2014.09.017}
}
Launoy T, Chabot M, Martinet G, Pino T, LePadellec A, Bouneau S, Féraud G, Do Thi N, Vaeck N, Liévin J, Loreau J and Béroff K (2015), "Ion-pair dissociation of highly excited carbon clusters, size and charge effects", Journal of Physics: Conference Series. Vol. 635(3)
Abstract: Ion-pair dissociation of a highly excited molecule is a relaxation process giving rise to emission of anionic and cationic fragments. We present first measurements of ion-pair dissociation of carbon clusters. We found that ion- pair relaxation is an ubiquitous, although very small, relaxation channel common to all sizes and charges of Cq+n species produced in high velocity C+n-He collisions. Quantitative interpretation of measured branching ratios is conducted on the basis of a statistical approach i.e through listing of all possible final states. © Published under licence by IOP Publishing Ltd.
BibTeX:
@conference{Launoy2015,
  author = {Launoy, T. and Chabot, M. and Martinet, G. and Pino, T. and LePadellec, A. and Bouneau, S. and Féraud, G. and Do Thi, N. and Vaeck, N. and Liévin, J. and Loreau, J. and Béroff, K.},
  title = {Ion-pair dissociation of highly excited carbon clusters, size and charge effects},
  journal = {Journal of Physics: Conference Series},
  year = {2015},
  volume = {635},
  number = {3},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.1088/1742-6596/635/3/032085}
}
Launoy T, Vaeck N, Urbain X, Liévin J, Loreau J, Béroff K and Chabot M (2015), "On the reactivity of ion pairs into different diatomic systems", Journal of Physics: Conference Series. Vol. 635(2)
Abstract: Ion pair collisions are an important process in many astrophysical environments. We present ab initio calculations of highly excited states of C2+ and identify the ion pair channel C2+/C-. We use these results to interpret recent experiments on carbon cluster dissociation. © Published under licence by IOP Publishing Ltd.
BibTeX:
@conference{Launoy2015a,
  author = {Launoy, T. and Vaeck, N. and Urbain, X. and Liévin, J. and Loreau, J. and Béroff, K. and Chabot, M.},
  title = {On the reactivity of ion pairs into different diatomic systems},
  journal = {Journal of Physics: Conference Series},
  year = {2015},
  volume = {635},
  number = {2},
  note = {All Open Access, Gold Open Access},
  doi = {10.1088/1742-6596/635/2/022018}
}
Lyulin O, VanderAuwera J and Campargue A (2015), "The Fourier transform absorption spectrum of acetylene between 7000 and 7500cm-1", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 160, pp. 85 – 93.
Abstract: High resolution (0.011cm-1) room temperature (295K) Fourier transform absorption spectra (FTS) of acetylene have been recorded between 7000 and 7500cm-1. Line parameters (positions, intensities and self broadening coefficients) have been measured using a multispectrum treatment of three FTS spectra, recorded at 3.84, 8.04 and 56.6hPa. As a result, a list of 3788 lines was constructed with intensities ranging between about 10-26 and 10-22cm/molecule. Comparison with accurate predictions provided by a global effective operator model (Lyulin OM, Perevalov VI, Teffo JL, Proc. SPIE 2004;5311:134-43) led to the assignment of 2471 of these lines to 12C2H2. The assigned lines belong to 29 12C2H2 bands, 12 of them being newly reported. Spectroscopic parameters of the upper vibrational levels were derived from band-by-band fits of the line positions (typical rms values are on the order of 0.001cm-1). About half of the analyzed bands were found to be affected by rovibrational perturbations. Line parameters obtained in this work were compared with those available for about 350 transitions in the HITRAN 2012 database. The large set of new data will be valuable to refine the parameters of the global effective Hamiltonian and dipole moments of 12C2H2. © 2015 Elsevier Ltd.
BibTeX:
@article{Lyulin2015,
  author = {Lyulin, O.M. and VanderAuwera, J. and Campargue, A.},
  title = {The Fourier transform absorption spectrum of acetylene between 7000 and 7500cm-1},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2015},
  volume = {160},
  pages = {85 – 93},
  doi = {10.1016/j.jqsrt.2015.03.018}
}
Nazé C, Li J and Godefroid M (2015), "Theoretical isotope shifts in neutral barium", Physical Review A - Atomic, Molecular, and Optical Physics. Vol. 91(3)
Abstract: The present work deals with a set of problems in isotope shifts of neutral barium spectral lines. Some well-known transitions (6s21S0-6s6p1,3P1o and 6s21S0-6p23P0) are investigated. Values of the changes in the nuclear mean-square charge radius are deduced from the available experimental isotope shifts using our ab initio electronic factors. The three sets δ r2A,A′ obtained from these lines are consistent with each other. The combination of the available nuclear mean-square radii with our electronic factors for the 6s5d3D1,2-6s6p1P1o transitions produces isotope shift values in conflict with the laser spectroscopy measurements of U. Dammalapati et al. [Eur. Phys. J. D 53, 1 (2009)EPJDF61434-606010.1140/epjd/e2009-00076-x]. © 2015 American Physical Society.
BibTeX:
@article{Naze2015,
  author = {Nazé, C. and Li, J.G. and Godefroid, M.},
  title = {Theoretical isotope shifts in neutral barium},
  journal = {Physical Review A - Atomic, Molecular, and Optical Physics},
  year = {2015},
  volume = {91},
  number = {3},
  note = {All Open Access, Green Open Access},
  doi = {10.1103/PhysRevA.91.032511}
}
Predoi-Cross A, Liu W, Murphy R, Povey C, Gamache R, Laraia A, McKellar A, Hurtmans D and Devi V (2015), "Corrigendum to "Measurement and computations for temperature dependences of self-broadened carbon dioxide transitions in the 30012-00001 and 30013-00001 bands" [J. Quant. Spectrosc. Radiat. Transf., 111 (9) (2010) 1065-1079] doi: 10.1016/j.jqsrt.2010.01.003", Journal of Quantitative Spectroscopy and Radiative Transfer. Vol. 164, pp. 256.
BibTeX:
@article{PredoiCross2015,
  author = {Predoi-Cross, Adriana and Liu, W. and Murphy, Reba and Povey, Chad and Gamache, R. and Laraia, A. and McKellar, A.R.W. and Hurtmans, Daniel and Devi, V.M.},
  title = {Corrigendum to "Measurement and computations for temperature dependences of self-broadened carbon dioxide transitions in the 30012-00001 and 30013-00001 bands" [J. Quant. Spectrosc. Radiat. Transf., 111 (9) (2010) 1065-1079] doi: 10.1016/j.jqsrt.2010.01.003},
  journal = {Journal of Quantitative Spectroscopy and Radiative Transfer},
  year = {2015},
  volume = {164},
  pages = {256},
  doi = {10.1016/j.jqsrt.2015.06.017}
}
Safieddine S, Boynard A, Hao N, Huang F, Wang L, Ji D, Barret B, Ghude S, Coheur P-F, Hurtmans D and Clerbaux C (2015), "Tropospheric Ozone Variability during the East Asian Summer Monsoon as Observed by Satellite (IASI), Aircraft (MOZAIC) and Ground Stations", Atmospheric Chemistry and Physics Discussions. Vol. 15(21), pp. 31925 – 31950.
Abstract: Satellite measurements from the thermal Infrared Atmospheric Sounding Interferometer (IASI), the Measurements of OZone and water vapor by in-service AIrbus airCraft (MOZAIC), as well as observations from ground based stations, are used to assess the tropospheric ozone (O3) variability during the East Asian Summer Monsoon (EASM). Six years [2008-2013] of IASI data analysis reveals the ability of the instrument to detect the onset and the progression of the monsoon reflected by a decrease in the tropospheric [0-6] km O3 column due to the EASM, and to reproduce this decrease from one year to the other. Focusing on the period of May-August 2011, taken as an example year, IASI data show clear inverse relationship between tropospheric [0-6] km O3 on one hand and meteorological parameters such as cloud cover, relative humidity and wind speed, on the other hand. Aircraft data from the MOZAIC project at Hyderabad, Nanjing and Guangzhou are used to validate the IASI data and to assess the effect of the monsoon on the vertical distribution of the tropospheric O3 at different locations. Results show good agreement with a correlation coefficient of 0.74 between the [0-6] km O3 column derived from IASI and MOZAIC. The aircraft data show a decrease in the tropospheric O3 that is more important in the free troposphere than in the boundary layer and at Hyderabad than at the other two Chinese cities. Ground station data at different locations in India and China show a spatiotemporal dependence on meteorology during the monsoon, with decrease up to 22 ppbv in Hyderabad, and up to 5 ppbv in the North China Plain. © Author(s) 2015.
BibTeX:
@article{Safieddine2015,
  author = {Safieddine, S. and Boynard, A. and Hao, N. and Huang, F. and Wang, L. and Ji, D. and Barret, B. and Ghude, S.D. and Coheur, P.-F. and Hurtmans, D. and Clerbaux, C.},
  title = {Tropospheric Ozone Variability during the East Asian Summer Monsoon as Observed by Satellite (IASI), Aircraft (MOZAIC) and Ground Stations},
  journal = {Atmospheric Chemistry and Physics Discussions},
  year = {2015},
  volume = {15},
  number = {21},
  pages = {31925 – 31950},
  note = {All Open Access, Green Open Access, Hybrid Gold Open Access},
  doi = {10.5194/acpd-15-31925-2015}
}
Santos L, Iacobellis N, Herman M, Perry D, Desouter-Lecomte M and Vaeck N (2015), "A test of optimal laser impulsion for controlling population within the N s = 1, N r = 5 polyad of 12C 2H 2 ", Molecular Physics. Vol. 113(24), pp. 4000 – 4006.
Abstract: Optimal control theory has been employed to populate separately two dark states of the acetylene polyad, Ns = 1 and Nr = 5, by indirect coupling via the ground state. Relevant level energies and transition dipole moments are extracted from the experimental literature. The optimal pulses are rather simple. The evolution of the population is shown for the duration of the control process and also for the field-free evolution that follows the control. One of the dark states appears to be a potential target for realistic experimental investigation because the average population of the Rabi oscillation remains high and decoherence is expected to be weak. © 2015 Taylor and Francis.
BibTeX:
@article{Santos2015a,
  author = {Santos, L. and Iacobellis, N. and Herman, M. and Perry, D.S. and Desouter-Lecomte, M. and Vaeck, N.},
  title = {A test of optimal laser impulsion for controlling population within the N s = 1, N r = 5 polyad of 12C 2H 2 },
  journal = {Molecular Physics},
  year = {2015},
  volume = {113},
  number = {24},
  pages = {4000 – 4006},
  note = {All Open Access, Green Open Access},
  doi = {10.1080/00268976.2015.1102980}
}
Santos L, Justum Y, Vaeck N and Desouter-Lecomte M (2015), "Simulation of the elementary evolution operator with the motional states of an ion in an anharmonic trap", Journal of Chemical Physics. Vol. 142(13)
Abstract: Following a recent proposal of L. Wang and D. Babikov [J. Chem. Phys. 137, 064301 (2012)], we theoretically illustrate the possibility of using the motional states of a Cd+ ion trapped in a slightly anharmonic potential to simulate the single-particle time-dependent Schrödinger equation. The simulated wave packet is discretized on a spatial grid and the grid points are mapped on the ion motional states which define the qubit network. The localization probability at each grid point is obtained from the population in the corresponding motional state. The quantum gate is the elementary evolution operator corresponding to the time-dependent Schrödinger equation of the simulated system. The corresponding matrix can be estimated by any numerical algorithm. The radio-frequency field which is able to drive this unitary transformation among the qubit states of the ion is obtained by multi-target optimal control theory. The ion is assumed to be cooled in the ground motional state, and the preliminary step consists in initializing the qubits with the amplitudes of the initial simulated wave packet. The time evolution of the localization probability at the grids points is then obtained by successive applications of the gate and reading out the motional state population. The gate field is always identical for a given simulated potential, only the field preparing the initial wave packet has to be optimized for different simulations. We check the stability of the simulation against decoherence due to fluctuating electric fields in the trap electrodes by applying dissipative Lindblad dynamics. © 2015 AIP Publishing LLC.
BibTeX:
@article{Santos2015,
  author = {Santos, Ludovic and Justum, Yves and Vaeck, Nathalie and Desouter-Lecomte, M.},
  title = {Simulation of the elementary evolution operator with the motional states of an ion in an anharmonic trap},
  journal = {Journal of Chemical Physics},
  year = {2015},
  volume = {142},
  number = {13},
  note = {All Open Access, Green Open Access},
  doi = {10.1063/1.4916355}
}
Schullian O, Loreau J, Vaeck N, Avoird AVD, Heazlewood B, Rennick C and Softley T (2015), "Simulating rotationally inelastic collisions using a direct simulation Monte Carlo method", Molecular Physics. Vol. 113(24), pp. 3972 – 3978.
Abstract: A new approach to simulating rotational cooling using a direct simulation Monte Carlo (DSMC) method is described and applied to the rotational cooling of ammonia seeded into a helium supersonic jet. The method makes use of ab initio rotational state changing cross sections calculated as a function of collision energy. Each particle in the DSMC simulations is labelled with a vector of rotational populations that evolves with time. Transfer of energy into translation is calculated from the mean energy transfer for this population at the specified collision energy. The simulations are compared with a continuum model for the on-axis density, temperature and velocity; rotational temperature as a function of distance from the nozzle is in accord with expectations from experimental measurements. The method could be applied to other types of gas mixture dynamics under non-uniform conditions, such as buffer gas cooling of NH3 by He. © 2015 Taylor and Francis.
BibTeX:
@article{Schullian2015,
  author = {Schullian, O. and Loreau, J. and Vaeck, N. and Avoird, A. Van Der and Heazlewood, B.R. and Rennick, C.J. and Softley, T.P.},
  title = {Simulating rotationally inelastic collisions using a direct simulation Monte Carlo method},
  journal = {Molecular Physics},
  year = {2015},
  volume = {113},
  number = {24},
  pages = {3972 – 3978},
  note = {All Open Access, Green Open Access},
  doi = {10.1080/00268976.2015.1098740}
}
Softley T, Herman M and Vaeck N (2015), "Special issue on atomic and molecular collision mechanisms", Molecular Physics. Vol. 113(24), pp. 3917.
BibTeX:
@article{Softley2015,
  author = {Softley, Tim and Herman, Michel and Vaeck, Nathalie},
  title = {Special issue on atomic and molecular collision mechanisms},
  journal = {Molecular Physics},
  year = {2015},
  volume = {113},
  number = {24},
  pages = {3917},
  note = {All Open Access, Bronze Open Access},
  doi = {10.1080/00268976.2015.1114702}
}
Stavrakou T, Müller J-F, Bauwens M, De Smedt I, vanRoozendael M, De Mazière M, Vigouroux C, Hendrick F, George M, Clerbaux C, Coheur P-F and Guenther A (2015), "How consistent are top-down hydrocarbon emissions based on formaldehyde observations from GOME-2 and OMI?", Atmospheric Chemistry and Physics. Vol. 15(20), pp. 11861 – 11884.
Abstract: The vertical columns of formaldehyde (HCHO) retrieved from two satellite instruments, the Global Ozone Monitoring Instrument-2 (GOME-2) on Metop-A and the Ozone Monitoring Instrument (OMI) on Aura, are used to constrain global emissions of HCHO precursors from open fires, vegetation and human activities in the year 2010. To this end, the emissions are varied and optimized using the adjoint model technique in the IMAGESv2 global CTM (chemical transport model) on a monthly basis and at the model resolution. Given the different local overpass times of GOME-2 (09:30 LT) and OMI (13:30 LT), the simulated diurnal cycle of HCHO columns is investigated and evaluated against ground-based optical measurements at seven sites in Europe, China and Africa. The modeled diurnal cycle exhibits large variability, reflecting competition between photochemistry and emission variations, with noon or early afternoon maxima at remote locations (oceans) and in regions dominated by anthropogenic emissions, late afternoon or evening maxima over fire scenes, and midday minima in isoprene-rich regions. The agreement between simulated and ground-based columns is generally better in summer (with a clear afternoon maximum at mid-latitude sites) than in winter, and the annually averaged ratio of afternoon to morning columns is slightly higher in the model (1.126) than in the ground-based measurements (1.043). The anthropogenic VOC (volatile organic compound) sources are found to be weakly constrained by the inversions on the global scale, mainly owing to their generally minor contribution to the HCHO columns, except over strongly polluted regions, like China. The OMI-based inversion yields total flux estimates over China close to the bottom-up inventory (24.6 vs. 25.5 TgVOC yrg-1 in the a priori) with, however, pronounced increases in the northeast of China and reductions in the south. Lower fluxes are estimated based on GOME-2 HCHO columns (20.6 TgVOC yrg-1), in particular over the northeast, likely reflecting mismatches between the observed and the modeled diurnal cycle in this region. The resulting biogenic and pyrogenic flux estimates from both optimizations generally show a good degree of consistency. A reduction of the global annual biogenic emissions of isoprene is derived, of 9 and 13 % according to GOME-2 and OMI, respectively, compared to the a priori estimate of 363 Tg in 2010. The reduction is largest (up to 25-40 %) in the Southeastern US, in accordance with earlier studies. The GOME-2 and OMI satellite columns suggest a global pyrogenic flux decrease by 36 and 33 %, respectively, compared to the GFEDv3 (Global Fire Emissions Database) inventory. This decrease is especially pronounced over tropical forests, such as in Amazonia, Thailand and Myanmar, and is supported by comparisons with CO observations from IASI (Infrared Atmospheric Sounding Interferometer). In contrast to these flux reductions, the emissions due to harvest waste burning are strongly enhanced over the northeastern China plain in June (by ca. 70 % in June according to OMI) as well as over Indochina in March. Sensitivity inversions showed robustness of the inferred estimates, which were found to lie within 7 % of the standard inversion results at the global scale. © Author(s) 2015.
BibTeX:
@article{Stavrakou2015,
  author = {Stavrakou, T. and Müller, J.-F. and Bauwens, M. and De Smedt, I. and vanRoozendael, M. and De Mazière, M. and Vigouroux, C. and Hendrick, F. and George, M. and Clerbaux, C. and Coheur, P.-F. and Guenther, A.},
  title = {How consistent are top-down hydrocarbon emissions based on formaldehyde observations from GOME-2 and OMI?},
  journal = {Atmospheric Chemistry and Physics},
  year = {2015},
  volume = {15},
  number = {20},
  pages = {11861 – 11884},
  note = {All Open Access, Gold Open Access, Green Open Access},
  doi = {10.5194/acp-15-11861-2015}
}
Suas-David N, Vanfleteren T, Földes T, Kassi S, Georges R and Herman M (2015), "The Water Dimer Investigated in the 2OH Spectral Range Using Cavity Ring-Down Spectroscopy", Journal of Physical Chemistry A. Vol. 119(39), pp. 10022 – 10034.
Abstract: Two setups based on CW cavity ring-down spectroscopy were used at Bruxelles and Rennes to record jet-cooled water dimer absorption between 7188 and 7285, and between 7357 and 7386 cm-1. Some 19 absorption features are reported, significantly more than in the literature. Limited high-resolution information is available due to strong overlap between neighboring vibration-rotation-tunneling (VRT) structures and to spectral broadening induced by short upper state vibrational predissociation lifetimes, likely to range between 100 and 20 ps. Rotational band contours analyses are performed to assign the partly resolved VRT structures to the v1v2v3,vfvb = 000,11; 200,00; 000,20; and 101,00 zero-order vibrational states. Their wavenumbers are found to be 7192.34, 7225.86, 7240.57, and 7256.99 cm-1, respectively. Both so-called acceptor-switching tunneling components are involved in the assignments whose tentative character is discussed. © 2015 American Chemical Society.
BibTeX:
@article{SuasDavid2015,
  author = {Suas-David, N. and Vanfleteren, T. and Földes, T. and Kassi, S. and Georges, R. and Herman, M.},
  title = {The Water Dimer Investigated in the 2OH Spectral Range Using Cavity Ring-Down Spectroscopy},
  journal = {Journal of Physical Chemistry A},
  year = {2015},
  volume = {119},
  number = {39},
  pages = {10022 – 10034},
  doi = {10.1021/acs.jpca.5b06746}
}
Sutcliffe BT (2015), "The quantum form of the reaction path Hamiltonian", Molecular Physics. Vol. 113(13-14), pp. 1600 – 1607.