Impacts of surface boundary conditions on regional climate model simulations of European climate during the Last Glacial Maximum

We examine the influences of North Atlantic sea surface temperatures (SSTs) and vegetation on regional climate simulations over Europe during the Last Glacial Maximum (LGM). Simulated regional temperature and precipitation patterns over Europe are considerably improved when using revised SSTs based on proxy data. Likewise, the simulated permafrost is more accurately reproduced with the SST modifications. These improvements are partially related to the changed regional atmospheric circulation due to the revised SSTs, leading to colder and drier conditions over Western Europe. Further sensitivity tests with prescribed vegetation for LGM conditions provide evidence of the sensitivity of the simulated glacial climate. This study reveals the importance of considering more realistic SST and vegetation boundary conditions for a more accurate representation of regional climate variability under glacial conditions.