The seasonal cycle of snow cover, sea ice and surface albedo

Abstract Satellite data are used to construct monthly mean snow cover maps for the Northern Hemisphere. The zonally averaged snow cover from these maps is calculated and used, along with zonally averaged sea ice cover and detailed data on land surface types, to calculate the seasonal cycle of zonally averaged surface albedo. A parameterization is presented of the solar zenith angle effect on ocean albedo. The effects of meltwater on the surface, solar zenith angle and cloudiness are all parameterized and included in the calculations of snow and ice albedo. It is found that meltwater effects are very important, but that zenith angle and cloudiness effects are negligible. The albedo results for January, April, July, and October and the annual average results are compared to calculations by several other workers. The discrepancies are explained in terms of the above-mentioned effects and the averaging methods used. It is found that several other workers failed to weight the albedos by solar radiation when ca...