Helene De Longueville

Background

• BA in chemistry, UNamur (2014-2017)
• MA in chemistry, ULB (2017-2019)
• Master thesis: Espèces halogénées à long temps de vie : identification spectrale et tendances sur dix ans à partir des mesures du sondeur IASI, ULB (2019)
• PhD student in Sciences, ULB, FRIA grant (2019-present)

PhD project

Monitoring of atmospheric halocarbons by exploiting global measurements from the IASI/Metop sounders.

The emissions of halocarbons have profoundly modified the chemical and radiative equilibrium of the atmosphere. Following the Montreal protocol and its amendments, the concentrations of the chlorofluorocarbons (CFCs) have started to decline in the early-2000, however at slower rate than anticipated for CFC-11, probably because of new industrial emissions. In parallel, the concentrations of the hydrogenated substitutes have increased, and new chlorine species were found at significant concentrations. Together they maintain the chlorine load to a substantial level, which could delay the recovery of stratospheric ozone.
Halocarbons are also characterized by a large global warming potential. The monitoring of the halocarbons is therefore essential.
The aim of the project is to assess the potential of infrared satellite sounders operating in the nadir geometry, to contribute to this monitoring and thereby complement existing surface measurement networks. The research work is centered on the exploitation of the measurements from the IASI sounder. The challenges are (1) to isolate the weak spectral signatures of the halocarbons from IASI measurements and (2) determine the evolution of their concentrations from the 15 years of IASI measurements. The spatial variability in the concentrations will be carefully looked at in order to possibly isolate local sources. Finally, the radiative impact of the halocarbons will be assessed.

Publications

See here.

Contact

Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES)(https://squares.ulb.be//),
Université Libre de Bruxelles, CP160/09
50 Av. F.D. Roosevelt, B-1050 Belgium
E-mail