Description du sujet de thèse

Using satellite imagery and sounding to characterize aerosols in a kilometer-scale Earth system model.

Recent and ongoing work at CNRM aims to describe aerosols in terms of optical thickness (AOD) using the FCI instrument on board MTG. In addition, the direct assimilation of spectral radiances from IASI and future IRS measurements into meteorological and AROME models demonstrates the unprecedented contribution of these instruments to meteorological variables. A PhD thesis in progress aims to assimilate the spectral radiances of IASI and IASI-NG in the atmospheric composition model MOCAGE to initialize desert aerosols, as well as to address the synergy between IASI(-NG) and IRS for these aerosols. In addition, CNRM is currently developing Earth System versions of AROME, which will enable, among other things, meteorological atmosphere and atmospheric composition to be described in the same model. This will enable, for example, better modeling of atmospheric radiation.
The main objective of this thesis is to explore the assimilation of IRS and FCI in the AROME Earth System model, in order to initialize meteorological and aerosol fields in a coherent, fine-scale manner.
A first part will be dedicated to the study of the sensitivity and information content for desert dust of the IRS and FCI instruments, as well as to the possible evolutions of the FCI instrument, which can be used for the assimilation of meteorological and aerosol fields.
In a second part, the assimilation of IRS spectral radiances in AROME for desert aerosols will be evaluated, as well as possible complements based on FCI AOD data. The improvement of meteorological fields will also be evaluated. Assimilation parameters will be studied for possible adaptation.

Contexte de travail

The successful candidate will work within the CNRM PLASMA team. The work will be carried out in close collaboration with several colleagues from different CNRM teams working on the assimilation of observations into CNRM models, as well as with a scientific manager from the industrial company designing the IRS instrument.
The PhD student will be enrolled at the University of Toulouse (SDU2E doctoral school).
The CNRM laboratory is presented here: https://www.umr-cnrm.fr
Skills required include
- ability to carry out a supervised scientific project as part of a research team, and to present results both orally and in writing. Previous experience in a research internship at M2 or engineering school level is essential.
- knowledge of atmospheric remote sensing (particularly satellite-based), numerical modeling and statistics
- good knowledge of Fortran 90 (in assimilation software) and Python (for scientific data processing and visualization)
- fluency in English: one of the aims of the thesis is to write a scientific article in English, and make presentations at international conferences.

Contraintes et risques

None.