A wind-driven snow redistribution module for Alpine3D v3.3.0: adaptations designed for downscaling ice sheet surface mass balance

Abstract. Ice sheet surface mass balance describes the net snow accumulation at ice surface. On Antarctic sheet, winds redistribute snow, resulting in a that is variable both space and time. Representing wind-driven redistribution processes models critical for local assessments of balance, repeat altimetry studies, interpretation core records. To this end, we have adapted Alpine3D, an existing distributed modeling framework, to downscale horizontal resolutions up 1 km. In particular, introduced new two-dimensional advection-based module driven by offline coupling between WindNinja, wind downscaling model, Alpine3D. We then show large variability can be least partially explained terrain-induced speed variations which subsequently around rolling topography. By comparing Alpine3D airborne-derived measurements within testing domain over Pine Island Glacier West Antarctica, demonstrate our approach improves estimates when compared Modern-Era Retrospective analysis Research Applications, Version 2 (MERRA-2), global atmospheric reanalysis use as forcing. MERRA-2, reduces simulated root mean squared error 23.4 mmw.e.yr-1 (13 %) increases variance 24 %. Despite these improvements, results considerable uncertainty stems from employed saltation confounding simulations variability.