LASER MICROPROBE MASS ANALYSIS OF AMAZON BASIN AEROSOLS

Individual aerosol particles sampled over the Amazon Basin, Brazil, we re analysed using laser microprobe mass analysis (LAMMA). Spectra are complex due to the high organic content of the samples. Phosphate was found to be concentrated largely in one particle type, which was only detected in the dry season samples. This points to a biomass burning o rigin or at least to a season-related vegetative aerosol production me chanism. The most abundant particle type, most likely originating from a vegetation source, can be described as a mixture of different salts and organic fragments.