Dust absorption averaged over the Sahara inferred from moderate resolution imaging spectroradiometer

摘要

We estimated the average dust single scattering albedo (omega(0)) over the Sahara using four years of moderate resolution imaging spectroradiometer data. The method employed is based on the theory that the critical surface reflectance (rho(c)) for which the reflectance at the top-of-the-atmosphere is not influenced by the variability of dust optical thickness depends on omega(0). The average dust absorption over the Sahara was estimated to be smaller than that previously reported in the literature, and this may be causing the cooling of the climate system. Our method enables one to estimate omega(0) from data with a variety of aerosol optical thickness values using samples in the vicinity of rho(c). Use of satellite data over large areas and for long periods enables quantification of the average dust absorption over the entire Sahara. (D 2008 Optical Society of America