Fate of heat approaching the Filchner-Ronne Ice Shelf mediated by continental shelf eddies.

Abstract

Transfer of ocean heat toward Antarctica's ice shelves is a key driver of changes in glacial mass balance. Previous work has indicated that transfer of warm, mid-depth waters across the continental slope is elevated close to Antarctica's largest ice shelves, where dense waters form over the continental shelf. Yet, ice shelves in such regions maintain relatively low area-averaged melt rates, suggesting that ocean processes must shield them from the inflowing heat. In this study, a high-resolution simulation is used to isolate the mechanisms of heat transfer toward the Filchner-Ronne Ice Shelf in the southern Weddell Sea. This study shows that ocean eddies divert almost all heat arriving on the continental shelf up to the ocean surface and away from the ice shelf by stirring heat anomalies along tilted density surfaces. These findings highlight the importance of understanding continental shelf eddies in the context of basal melt variability, for example, in driving future heat delivery to Antarctica's largest ice shelves.