Detailed simulations of spatial snow accumulation and properties in Dronning Maud Land

Abstract:

Snow accumulation is an important component of Antarctic Ice Sheet surface mass balance. However, accumulation rates are generally low, and snow redistribution by wind is not only common, but also of the same order of magnitude as precipitation. This poses difficulty in assessing Surface Mass Balance (SMB), for example, in modeling or remote sensing retrievals. In this study, we apply the physics-based, multi-layer snow model SNOWPACK in a distributed mode to simulate near-surface snow processes at 1 km resolution. MERRA-2 reanalysis is used as forcing. The model calculates snow erosion based on snow microstructural properties and downscaled surface winds. The simulations cover a 200x200 km area near the Princess Elisabeth Station in Dronning Maud Land, stretching from the coastal area to the edge of the Antarctic Plateau. A rich dataset of high-resolution snow microstructure and density measurements of the near-surface, repeat terrestrial laser scanning to determine snow erosion and deposition patterns, and blowing snow observations are used to evaluate the model. The model results show a good agreement in the spatial and temporal patterns in near-surface snow density profiles, and timing of blowing snow events. The contrasting snow properties found in the coastal areas and the Antarctic Plateau are successfully reproduced. The simulations demonstrate how the snow layering is determined by wind erosion and deposition, which improves our understanding of the role of drifting snow in the Antarctic SMB.