Enhanced light absorption and reduced snow albedo due to internally mixed mineral dust in grains of snow

Abstract. Mineral dust is a major light-absorbing aerosol, which can significantly reduce snow albedo and accelerate snow/glacier melting via wet dry deposition on snow. In this study, three scenarios of internal mixing in ice grains were analyzed theoretically by combining asymptotic radiative transfer theory (core–shell) Mie to evaluate the effects absorption coefficient semi-infinite snowpack consisting spherical grains. general, was substantially reduced at wavelengths <1.0 µm dust–snow mixing, with stronger reductions higher concentrations larger grain sizes. Moreover, calculations showed that nonuniform distribution lead significant differences values dust-contaminated visible relative uniform Finally, using comprehensive situ measurements across Northern Hemisphere, we found broadband further 5.2 % 9.1 due Tibetan Plateau North American mountains. This than reduction caused black carbon over most Arctic regions. Our results suggest important for retreat glaciers mountain snowpack.