Atmospheric response to Antarctic sea-ice reductions drives ice sheet surface mass balance increases

Abstract The mass balance of the Antarctic ice sheet is intricately linked to state surrounding atmosphere and ocean. As a direct result, improving projections future sea level change requires understanding in Southern Ocean, processes that couple these systems. Here, we examine influence cover on overlying subsequently surface (SMB) adjacent sheet. We investigate both over observational era using ERA5 atmospheric reanalysis ensemble simulations Community Earth System Model 2.1 (CESM2) where only coverage altered. Comparing extreme high low satellite reveals SMB anomalies largely mirror simulated by CESM2 response loss. Results highlight significant near-surface warming reductions are particularly pronounced nonsummer seasons driven ocean-to-atmosphere turbulent heat fluxes. In areas loss, ocean evaporation increases occur. On eastern flank climatological pressure systems, moisture readily advected toward sheet, driving positive SMB. These results indicate underestimation ice, which common many current-generation coupled climate models, may lead overestimation therefore Antarctica’s contributions global level. Significance Statement largest potential source rise. Its depend part how much snow accumulates across its surface. Through observation-incorporating data model sensitivity studies, find Ocean exerts an important Our show promote enhanced subsequent snowfall Because current models tend simulate too little conclude they overestimate snowfall, leading underprediction