Sensitivity of Multi-angle remote sensing observations to aerosol sphericity

Multi-angle, multi-spectral remote sensing observations, such as those anticipated from the Earth Observing System (EOS) multi-angle imaging spectroradiometer (MISR) can distinguish spherical from non-spherical particles over calm ocean, for mineral-dust-like particles with the range of sizes and column amounts expected under natural conditions. The ability to make such distinctions is critical if remote sensing of atmospheric aerosol properties is to provide significant new contributions to our understanding of the global-scale, clear-sky solar radiation balance. According to theoretical simulations, the measurements can retrieve column optical depth for non-spherical particles to an accuracy of at least 0.05 or 10%, whichever is larger. In addition, three to four distinct size groups between 0.1 and 2.0 microns effective radius can be identified at most latitudes.