Small‐Scale, High‐Frequency Ice, and Ocean Processes in the Amundsen Sea Embayment, West Antarctica

Abstract In proximity of the Antarctic ice sheet, oceanic motions with different spatial structures contribute to the transport of warm water onto the continental shelf, fueling submarine ice‐shelf melting. Emerging evidence suggests that km‐sized ocean submesoscale fronts and eddies significantly impact ice‐ocean interactions on timescale of a few hours to a few days, with profound implications for the melting regime. However, ocean models often rely on parameterizations to represent these fine‐scale, high‐frequency processes because of the coarse resolution. This results in uncertainties in heat transfer mechanisms at the ice‐ocean boundary which often leads to conservative estimations of melt rates. Here, we assess the impact of sub‐kilometer model resolution on capturing ocean features at different scales in the Amundsen Sea Embayment, West Antarctica, and their impact on the melting regime of local ice shelves. While the simulations do not show substantial differences in large‐scale ocean dynamics, we find that using a sub‐kilometer resolution is necessary to resolve ocean eddies beneath ice shelves. Furthermore, the ocean kinetic energy using 200 m resolution is approximately three times higher than when using a 1 km resolution. This increase is driven by significantly stronger submesoscale activity, both in the open ocean and beneath the ice shelves, leading to improved model‐data agreement, particularly in capturing high melt rates observed at the grounding line.