Biomass burning aerosol characterisctics over Benin

Pelon,  J., M. Mallet, A. Mariscal, P. Goloub, D. Tanré, D. Bou Karam, C. Flamant, J. Haywood, B. Pospichal, S. Victori: “Characterisation of biomass burning aerosol from microlidar observations at Djougou (Benin) during AMMA-SOP0/DABEX”, J. Geophys. Res., 113, D00C18,  doi:10.1029/2008JD009976. 

Abstract:

Microlidar observations performed at the Djougou-Nangatchori site in northern Benin, have been performed during the AMMA-SOP 0/DABEX intensive observation period of AMMA in the dry season, from mid-January to mid-February 2006. During the dry season, the Djougou area is a region where biomass burning aerosols are heavily produced from agriculture fires.

The aerosol vertical distribution is also controlled by dynamics, as the penetration of the winter monsoon flux to the north, and northern winds bring mineral dust leads to a frontal discontinuity location close to Djougou latitude. During the early dry season, the aerosol vertical distribution was observed to be structured in two layers, the lower being the boundary layer reaching altitudes up to 2 km, and an upper layer reaching 4 to 5 km.

Lidar data are used to retrieve the time evolution and vertical profile of extinction, and discuss transport processes during the period analyzed. As the monsoon flux during the dry season is steadily progressing to the north, but also moving back and forth according to shorter time scale forcings, biomass burning particles are transported from the boundary layer into the upper troposphere. This transport has a strong impact on the distribution of aerosol particles on the vertical, and extinction values larger than 0.3 km-1 have been retrieved at altitudes close to 3 km.

A particular event of biomass burning air mass outbreak associated with a synoptic forcing is studied, where satellite observations are used to discuss observations of biomass burning particles over Djougou and at the regional scale.

Main goal

I’m interested in evaluating the radiative impact of aerosol dust on atmospheric dynamics which is an important component of the climate system but is still poorly quantified.

To reach my goals, I use an observations-modelling coupled aproach.

In term of modelling my mean is the regional atmospheric model MesoNH coupled with a dust emission model (the DEAD model) together with the ECWMF analyses. In term of observations, I use the measurements collected during two field campaigns: the BoDEx campaign 2005 and the SOP2a1 2006 of the AMMA project where airborne LIDAR and ground based measurements of meteorological variables were performed. Satellite observations are also investigated in my studies such as CALIPSO , OMI , MODIS and SEVIRI data. For more details, please check the other sections on this website.