Numerical simulation of a severe blowing snow event over the Prydz Bay Region

Abstract

Antarctic blowing snow is a critical process regulating the mass balance of the ice sheet. From 15–17 July 2022, a mid-latitude cyclone invaded the Prydz Bay region of East Antarctica. Automatic weather stations at Zhongshan Station recorded a maximum minute-averaged wind speed exceeding 30 ms-1, while lidar ceilometer data and manual observations indicated that blowing snow persisted for approximately 36 h, marking the most intense blowing snow event of that year. This study reproduced the process using the CRYOWRF model and found that the strong winds induced by the cyclone triggered blowing snow and generated complex nonlinear motions under the influence of local topography, in turn shaping the transport of blowing snow. Topographically forced strong winds also triggered heavy snowfall, which replenished the wind-eroded snow layer. After deposition, this snow was more easily entrained by winds, mixing with falling snow to form blizzards. These results highlight the complexity of blowing snow processes in Antarctic coastal zones, which encompass topographic forcing on atmospheric circulation as well as dynamic feedback between snowfall and blowing snow. Therefore, adopting high-resolution non-hydrostatic numerical models combined with multi-source observations to accurately capture the key physical details of this complex process is of irreplaceable significance for the precise assessment of the Antarctic regional surface mass balance.