The role of ice-sheet topography in the Alpine hydro-climate at glacial times

Abstract. In this study, we investigate the sensitivity of glacial Alpine hydro-climate to northern hemispheric and local ice-sheet changes. Bridging scale gap by using a chain global regional climate models, perform simulations up 2 km horizontal resolution over Alps for Last Glacial Maximum (LGM) Marine Isotope Stage 4 (MIS4). winter, find wetter conditions in southern part during LGM compared present day, which dynamical processes, i.e. changes wind speed direction, contribute substantially. During summer, expected drier most region LGM, as thermodynamics suggests under lower temperatures. The MIS4 shows enhanced winter precipitation is explained its warmer – thus, again thermodynamics. show that an increase thickness leads significant intensification conditions, mainly processes. Changing only Fennoscandian ice sheet less influential on precipitation, whereas modifications topography significantly alter precipitation; particular, reduction summer at face when lowering sheet. findings demonstrate play important role regulating thus permits better understanding patterns complex terrain times.