Albedo of summer snow on sea ice, Ross Sea, Antarctica

Abstract

Surface all‐wave albedo and physical parameters (grain radius, mass density, surface temperature, and stratification) of an austral summer snow cover on sea ice were measured in the Ross Sea during January‐February 1999. It was observed that (1) from north to south the snow surface temperature decreases, albedo increases, snow mass density decreases, snow composite grain radius decreases, and number density of composite grains increases; (2) the size of the clusters of snow grains (i.e., melt clusters and well‐bonded chains of grains), rather than the size of the individual snow grains, is the dominant parameter controlling albedo (the smaller the snow composite grain radius and the larger the number density are, the higher the albedo is); and (3) in determining the snow albedo, grain size dominates over the number density and the upper layers dominate over the lower layers. A comparison of the statistical relation between albedo and the averaged grain size shows that statistical significance is independent of the selection of the grain size averaging method. Suggestions for snow albedo parameterization are made.