Analysis of high-resolution basal melt rate in the southernmost end of Amery Ice Shelf

Although there is considerable research on the basal melting of the Amery Ice Shelf (AIS), high-resolution calculations of the basal melt rate are lacking. This gap hinders a detailed understanding of spatial and temporal variations in the ice shelf’s basal melting. This study utilizes the reference elevation model of Antarctica (REMA) digital elevation model (DEM) at a spatial resolution of 2 m from 2011 to 2020, combined with various remote sensing data, to calculate long-term high-resolution basal melt rates in the grounding zone of Lambert Glacier. It also explores the primary factors driving spatial and temporal variability. We calculated the basal melt rate at a resolution of 100 m and discovered AIS that there is a significant spatial variability in the basal melting of this region. The eastern side and the internal basal channels experience intense melting, while the western side generally melts less. Based on the spatial variability, we further demonstrate that the direction of ocean circulation within the ice cavity in the grounding zone of Lambert Glacier is clockwise from east to west. The basal melting also exhibits interannual variability, which is primarily influenced by changes in the regional wind field. The southward shift of the westerlies over Prydz Bay and its adjacent waters can promote the intrusion of modified circumpolar deep water (mCDW) from the eastern side of the ice shelf, and becomes cooler when descending southward. The southernmost ice shelf water (ISW) is formed by the mixing of the inflow water with local cold and melted fresher water, thereby further enhancing basal melting.