Ice-sheet mass balance during the Last Glacial Maximum

In the framework of the Paleoclimate Modelling Intercomparison Project (PMIP), simulations of the Last Glacial Maximum (LGM) have been performed. More than 10 different atmospheric general circulation models (AGCMs) have been used with the same boundary conditions: sea-surface temperatures prescribed by CLIMAP (1981), ice-sheet reconstruction provided by Peltier (1994), change in insolation, and reduced CO2 content. One of the major questions is to investigate whether the simulations of the LGM are in equilibrium with the prescribed ice-sheet reconstruction. To answer this question, we have used two different approaches. First, we analyze the results of a set of LGM simulations performed with different versions of the Laboratoire de Meteorologie Dynamique (LMD) AGCM and study the hydrologic and snow budgets over the Laurentide and Fennoscandian ice sheets. Second, we use the AGCM outputs to forte an ice-sheet model in order to investigate its ability to maintain the ice sheets as reconstructed by CLIMAP (1981) or Peltier (1994).