Retrieval of aerosol single-scattering properties from diffuse and direct irradiances: Numerical studies

Abstract

Two different methods have been developed to retrieve aerosol single-scattering albedo ω 0 (λ) and asymmetry factor g(λ) from the direct and diffuse spectral irradiances measured at the surface. One is the direct method, which assumes the Henyey-Greenstein phase function and retrieves ω 0 (λ) and g(λ) directly from the irradiances. The other is the indirect method, which calculates optimum ω 0 (λ) and g(λ) after roughly retrieving the size distribution and refractive index from the irradiances. Their retrieval accuracies were evaluated from intensive sensitivity tests for water-soluble, dust, and biomass-burning models. The retrieval accuracies of ω 0 (λ) and g(λ) were 0.01 to 0.06 and 0.02 to 0.13 for the direct method, and 0.00 to 0.03 and 0.00 to 0.06 for the indirect method. Copyright 2008 by the American Geophysical Union.