Simulation of the Last Glacial Inception with the Green McGill Paleoclimate Model

The "green'' McGill Paleoclimate Model ( MPM), which includes an interactive vegetation component, is run between 122 and 80 kyr Before Present ( BP) under Milankovitch forcing and Vostok-derived atmospheric CO2 concentration. The model simulates the last glacial inception ( LGI) at around 119 kyr BP, and the subsequent buildup of huge ice sheets over the high northern latitudes, especially North America. Due to the addition of a vegetation component and an improved land surface scheme in the MPM, the resulting ice sheet volume is relatively small over Eurasia but quite large over North America, which is in qualitative agreement with observations and represents a significant improvement over the LGI results from the previous version of the MPM. The reduction of the forest area at high northern latitudes during the inception phase, which is induced by decreased warm season insolation, is necessary for the ice sheets to grow over Eurasia and to have large ice sheet growth over North America.