The PI plans to determine the source characteristics of aerosols originating over the savannas of southwest Africa, including aerosol size distribution and composition, distinguishing between products from biomass burning and erosion of mineral soils, concentrations of water extractable nutrients in surface soils and in aerosols, fluxes of aerosols from identified source areas, and meteorological processes associated with aerosol emissions from source areas and subsequent long range transport. The PI plans to take advantage of data sets from the TRACE- A/SAFARI field programs to address both source characteristics and long range transports. Isotope characteristics of continental (both dry and wet) regimes will be used to fingerprint the source and trace the trajectories. Three-dimensional isobaric trajectory analysis will be carried out not only during the field experiment, but also for historical dry and wet conditions. The combined trajectory, isotope tracer and general circulation analysis will provide a framework to interpret the role of the atmosphere and the resultant transports of the aerosols. The PI plans to use the results of this work to infer consequences to both continental and oceanic ecosystems as a function of the airborne supply of nutrients.
