The development of East Antarctic ocean simulation with a focus on the Totten Glacier.

Antarctic ice-sheet mass loss is currently impacting global sea-level rise, deep-ocean circulation, marine ecosystems, and ocean-atmosphere carbon exchange. The Totten Glacier in East Antarctica has received increasing attention in recent years, due to its rapid mass loss and the warm ocean waters observed at the ice-shelf front. A key question in assessing and projecting Totten's impact concerns the mechanisms that drive intrusions of ocean heat toward the ice shelf cavity. To address this question, we developed satellite estimates of temporally-varying Totten Ice Shelf (TIS) melt rates and a high-resolution ocean model to examine the processes that influence melt at TIS. We show that the Antarctic Slope Current (ASC) impedes ocean heat intrusions and TIS melt increases when the ASC weakens. We also conduct sensitivity experiments showing that heat intrusions towards the TIS are strongly enhanced with coastal freshening, suggesting that freshening from ice loss in West Antarctica could trigger a chain reaction, leading to increased melt in East Antarctica and further coastal freshening. Finally, we present new model development that includes online coupling with biogeochemistry (ECCO-Darwin) and an ice sheet model (ISSM). This coupled ocean-ice-biogeochemistry modeling approach allows for a better understanding of the future trajectory of Totten Glacier, and its net impact on marine systems.