Solar radiation transfer in the surface snow layer in Dronning Maud Land, Antarctica

Spectroradiometer measurements of solar radiation (the broadest band used 400-900 nm) were performed above and inside the surface snow layer in western Dronning Maud Land, Antarctica, during the austral summer of 2009-2010. The vertical distributions of transmittance and the extinction coefficient were examined from the surface to a depth of 30 cm. Physical characterization of the snowpack included measurements of thickness, density, hardness (hand test), liquid-water content, and grain size and shape (from photographs of grains). The transmittance was <1% in the upper 20 cm and <27% in the upper 10 cm. The mean spectral diffuse extinction coefficient varied between 0.04 and 0.31 cm(-1) (10-20-cm layer). Using the spectral extinction coefficients of the 0-10-cm and 10-20-cm layers, the depth, where broadband (400-700-nm band) irradiance was 1% of the downwelling irradiance at the surface, was 50 cm. The density of the snow in the upper part of the snowpack (depth of 0-55 cm) varied from 300 to 440 kg m(-3). The predominant grain type was large rounded particles (RGIr) and the predominant grain size was 1 mm. (C) 2013 Elsevier B.V. and NIPR. All rights reserved.