Modeling drifting snow in Antarctica with a regional climate model: 2. Results

摘要

This paper presents a model study of the impact of drifting snow on the lower atmosphere, surface snow characteristics, and surface mass balance of Antarctica. We use the regional atmospheric climate model RACMO2.1/ANT with a high horizontal resolution (27 km), equipped with a drifting snow routine and forced by ERA-Interim (1989-2009) at its lateral and ocean boundaries. Drifting snow sublimation (SUds) is significant in Antarctica, especially in the coastal regions (>150 mm water equivalent yr~(-1) ). Integrated over the ice sheet, SUds removes —6% of the annually precipitated snow.Drifting snow interacts with the atmosphere, as it increases the lower atmospheric moisture content and reduces surface sublimation (SU_s), and leads to increased snowfall in regions where the atmosphere usually is close to saturation. Drifting snow sublimation (SUds) is smallest in summer, when katabatic wind speeds are lower and melting and surface sublimation consolidate the snow surface. Compared to a simulation without drifting snow, total sublimation (SUds + SUS) doubles on the grounded ice sheet if drifting snow is considered. Drifting snow erosion is locally significant, but can be neglected on a continent-wide scale.