Iceberg-induced snowdrift formation on Antarctic landfast sea ice: effects of wind and iceberg size

Abstract Snow cover influences sea ice thermodynamics and mass balance, making its distribution and properties critical to polar research. Grounded icebergs in coastal Antarctica substantially affect surface snow distribution and landfast sea ice patterns, which have received limited scientific attention. To address this gap, this study integrates airborne laser scanning observations with numerical snow transport simulations to investigate snow distribution on landfast ice around icebergs, emphasizing the influence of wind and iceberg size. Observations show that persistent wind directions shape characteristic snow patterns around icebergs, with substantial windward and lateral drifts and an elongated snow-depleted region in the lee. Data further reveal that snowdrift size scales nonlinearly with iceberg size, indicating reduced snow accumulation efficiency for larger icebergs, which simulations partially captured. This study also highlights the key role of wind direction shifts in reproducing measured snow distributions and suggests that the maximum extent of snowdrifts is constrained by peak wind speeds encountered on site. Together, our findings show that iceberg-induced snowdrifts connect ice shelf and fast ice dynamics, reflect local wind conditions and provide key insights into snow mass balance on Antarctic landfast sea ice.