Lejeudi 11 janvier 2024, Rodriguez YOMBO PHAKA présentera l'examen en vue de l’obtention du grade académique de Docteur en Sciences (Collège de doctorat en Sciences spatiales) sous la direction de Emmanuel MAHIEU et Jean-Pierre MBUNGU TSUMBU (Université de Kinshasa).

Cette épreuve consistera en la défense publique d’une dissertation intitulée :

« First MAX-DOAS observations of tropospheric NO₂ and H₂CO in Central Africa, impact on air quality and validation of the TROPOMI satellite instrument  ».

Abstract

This thesis addresses air pollution in Central Africa, with a focus on nitrogen dioxide (NO₂), formaldehyde (H₂CO), and aerosol pollution. Recent studies, utilizing satellite observations, reveal peaks in these pollutants, primarily attributed to biogenic emissions from the region's extensive forests, but also from biomass burning, forest fires, and charcoal production. The lack of ground-level measurements in Central Africa is emphasized.
The thesis operationalizes a remote sensing instrument based on Differential Optical Absorption Spectroscopy (DOAS) in Kinshasa. Data collected from May 2017 to July 2021 establish a pollution database, revealing significant levels of NO₂, H₂CO, and aerosols, particularly during the dry season. Daily cycles are identified, showing elevated levels around noontime.
Initial validation exercises of the TROPOMI satellite instrument demonstrate good agreement with ground observations, considering corrections based on the use of more representative MAX-DOAS measured profile as a priori information in the TROPOMI product. Evaluation of the GEOS-Chem model indicates its accuracy in replicating real atmospheric conditions, emphasizing the significant impact of biomass burning on NO₂ and H₂CO pollution.
This work underscores the need for more ground instruments in the sub-region. The need to inform the population is emphasized, as is the definition of effective measures to reduce pollution levels.

Lien Orbi

Le Jury sera composé de :

M. B. TYCHON (Président), Mme et MM. R. BOPILI MBOTIA LEPIBA (Université de Kinshasa), L. FRANCOIS (Secrétaire), E. MAHIEU (Promoteur), A. MERLAUD (IASB), J.-P. MBUNGU TSUMBU (Université de Kinshasa) (Co-promoteur), G. PINARDI (IASB).

Teams : Rejoindre la Défense