Atmospheric River Contributions to Ice Sheet Hydroclimate at the Last Glacial Maximum

Abstract Atmospheric rivers (ARs) are an important driver of surface mass balance over today's Greenland and Antarctic ice sheets. Using paleoclimate simulations with the Community Earth System Model, we find ARs also had a key influence on extensive sheets Last Glacial Maximum (LGM). provide up to 53% total precipitation along margins eastern Laurentide sheet 22%–27% Patagonian, western Cordilleran, Fennoscandian Despite overall cold conditions at LGM, temperatures during AR events often above freezing, resulting in more rain than snow that promote melt. The results suggest may have role growth melt previous glacial periods accelerated retreat following LGM.