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Snow accumulation is an important component of Antarctic Ice Sheet Surface Mass Balance (SMB). 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 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 and deposition based on surface 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 density and microstructure measurements of the near-surface, repeat terrestrial laser scanning to determine snow erosion and deposition patterns, as well as blowing snow observations, are used to evaluate the model simulations. 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 model reproduces the contrasting snow properties found in the coastal areas and the Antarctic Plateau. The detailed model output demonstrates how the snow layering is determined by wind erosion and deposition, improving our understanding of the role of drifting snow in the Antarctic SMB.
Michael Lehning, Tobias Jonas, Dylan Stewart Reynolds