Advanced Characterization of Aerosol through combination of remote sensing Active/Passive and In situ measurements

PhD student: Qiaoyun HU

Context
Aerosols are one of the most variable components of the atmosphere where these tiny particles interact with radiation and, at the surface level, they impact the air quality. Their diversity and their variability make their detection and detailed characterization quite complicated and often relying of complementary instrumentations.

The proposed thesis consists in enhancing the current inverse scheme, based on GRASP/GARRLIC development, by introducing available additional information provided by Raman LIDAR, spectral depolarization information in elastic channels and, also, in situ aerosol optical properties provided by a nephelometer at surface level.

Improvement and application of the current methodology, based on daytime joint inversion of sun-photometer and backscattered LIDAR data, have been successful during V. Bovchaliuk thesis supported by CaPPA project. The results are promising and provide more detailed information on the vertical distribution of aerosols properties.

This project will address the next step aiming at accounting for all data available from multi-wavelength-Raman-polarized LIDAR such as the one, LILAS, operated by LOA.

The candidate will have to address both experimental work in laboratory or during field campaigns (performing measurements with the LIDAR) and develop new algorithm accounting for the additional information from Raman and depolarization channels (day and night time measurements). A sensitivity study will be performed and experimental results will be validated on existing dataset from Lille, Dakar and during a field campaign scheduled in China.

This methodological development is quite relevant for a wide community involved in ORAURE national aerosol observation system and also with the ACTRIS (Aerosol Cloud Trace gas Infrastructure Project) in cooperation with ICARE.

Keywords: aerosols, optical and microphysical properties, vertical distribution, LIDAR, sun/lunar photometry, nephelometer, inverse method, GRASP

Thesis responsible: Philippe Goloub (LOA)
Co-responsible: Oleg Dubovik (LOA)

Laboratory: LOA

Financing: European Space Agency (ESA)