Airborne aerosols over central Africa during the Experiment for Regional Sources and Sinks of Oxidants (EXPRESSO)

As part of EXPRESSO conducted over central Africa in November 1996, 24 airborne aerosol samples were obtained and further analyzed for black and organic carbon, water-soluble organic carbon, polycyclic aromatic hydrocarbons, soluble ions, elemental composition, and morphology. The authors present a speciation of the particulate phase which shows the overwhelming contribution of fire-derived aerosols. The data give some insight into the important aging processes affecting the particles by comparing their physical and chemical characteristics in the different layers. For this purpose, the inorganic, organic, and black carbon particulate fractions were analyzed. The water-soluble component of the carbonaceous fraction was also evaluated as biomass burning organic particles are suspected to serve as cloud condensation nuclei agents. An interesting output of the data is the distribution of aerosols in the regional atmosphere. (AIAA)