REGIONAL STUDY OF SOUTHERN AFRICAN AEROSOLS USING COMPOUND SPECIFIC ISOTOPE ANALYSIS

This study, conducted as a part of the Southern African Regional Science Initiative (SAFARI 2000), applied compound specific isotope analysis (CSIA) to describe aerosols at source regions and rural locations. Stable carbon isotopic compositions of individual fatty acids were determined for aerosol samples collected at four sites throughout southern Africa. Mongu, Zambia and Skukuza, South Africa were chosen for their location within intense seasonal Miombo woodland savanna and bushveld savanna biomass burning source regions, respectively. Urban aerosols were collected at Johannesburg, South Africa and rural samples were collected at Sua Pan, Botswana. Fatty acid isotopic compositions varied temporally and as a function of synoptic-scale meteorology. Aerosol source region differences were also observed. For example, urban aerosols showed significant isotopic enrichment of selected short chain fatty acids (C < 20) compared to aerosols produced during biomass combustion. Additionally, atmospheric linkages between sites were hypothesized based on similarities within fatty acid profiles and signatures.