Sensitivity of the European LGM climate to North Atlantic sea-surface temperature

Recent reconstructions of Sea-Surface Temperatures (SSTs) for the Last Glacial Maximum (LGM, 21 kyr BP) based on foraminifera and dinoflagellate proxies suggest that the north Atlantic may have been warmer than estimated by CLIMAP [1981]. To better understand the impact of such a warm north Atlantic on the global LGM climate, we used two different AGCMs to perform sensitivity studies. With the new, warmer SSTs, both models simulate a hydrological cycle and temperatures very different from those obtained with the CLIMAP boundary conditions. The most noticeable differences occur in winter over North America and Siberia whereas southern Europe is only weakly affected at all seasons. Whichever the conditions prescribed over the north Atlantic, both models underestimate the large cooling recorded by continental proxy data over the Mediterranean Basin.