A seasonal trend of single scattering albedo in southern African biomass‐burning particles: Implications for satellite products and estimates of emissions for the world's largest biomass‐burning source

摘要: [1] As a representative site of the southern African biomass-burning region, sun-sky data from 15 year Aerosol Robotic Network (AERONET) deployment at Mongu, Zambia, was analyzed. For season months (July–November), we investigate seasonal trends in aerosol single scattering albedo (SSA), size distributions, and refractive indices almucantar sky scan retrievals. The monthly mean 440 nm Mongu found to increase significantly ~0.84 July ~0.93 November (from 0.78 0.90 675 nm these same months). There no significant change particle size, either dominant accumulation or secondary coarse modes during months, nor any trend Angstrom exponent (440–870 nm; r2 = 0.02). A downward imaginary index (r2 = 0.43) suggests decreasing black carbon content composition as burning progresses. Similarly, SSA retrievals for Etosha Pan, Namibia AERONET also show very similar increasing values Furthermore, 388 nm Ozone Monitoring Instrument satellite sensor observed by suggest that this shift is widespread throughout much Africa. retrieval bias optical depth Moderate Resolution Imaging Spectroradiometer collection 5 dark target algorithm consistent with since assumes constant value SSA. Multi-angle Spectroradiometer, however, appears less sensitive absorption-induced bias.