Large‐scale mass balance effects of blowing snow and surface sublimation

Abstract

This study examines the effects of surface sublimation and blowing snow on the surface mass balance on a global and basin scale using the European Centre for Medium‐Range Weather Forecasts (ECMWF) Re‐Analysis (ERA15) data at a resolution of 2.5° that span the years 1979–1993. The combined processes of surface and blowing snow sublimation are estimated to remove 29 mm yr−1 snow‐water equivalent (swe) over Antarctica, disposing about 17 to 20% of its annual precipitation. In the Northern Hemisphere, these processes are generally less important in continental areas than over the frozen Arctic Ocean, where surface and blowing snow sublimation deplete upward of 100 mm yr−1 swe. Areas with frequent blowing snow episodes, such as the coastal regions of Antarctica and the Arctic Ocean, are prone to a mass transport >100 Mg m−1 yr−1. Although important locally, values of the divergence of mass through wind redistribution are generally 2 orders of magnitude less than surface and blowing snow sublimation when evaluated over large areas. For the entire Mackenzie River Basin of Canada, surface sublimation remains the dominant sink of mass as it removes 29 mm yr−1 swe, or about 7% of the watershed's annual precipitation. Although the first of its kind, this study provides only a first‐order estimate of the contribution of surface sublimation and blowing snow to the surface mass balance because of limitations with the data set and some uncertainties in the blowing snow process.