Session: Glacial Climates (LGM, Last deglaciation, Ice sheet uncertainties, Glacial-interglacial cycles)
Author: Rumi Ohgaito / email@example.com / AORI, U. Tokyo
Co-author: Ayako Abe-Ouchi, AORI, U. Tokyo;
Ryouta O’ishi, AORI, U. Tokyo;
Toshihiko Takemura, Kyushu Univ.;
Last Glacial Maximum (LGM) is known with the enhancement of the dust deposition from the ice/sediment core data (Winckler et al. 2008, Dome Fuji Ice Core Project members 2017), especially over the polar
regions. Using an earth system model, MIROC-ESM (Watanabe et al.
2011), we investigated the impact of glaciogenic dust by Mahowald et
al. (2006) on LGM climate. We have found that the effect of the
enhancement of dust is less cooling in the polar regions. One of the
major reason of the less cooling is that the aging of snow or ice
albedo by high dust deposition mainly in the northern hemisphere.
Although the net radiative forcing at the lee of high glaciogenic dust
provenances are negative, warming by aging of snow overcomes the
change of the radiative forcing in MIROC-ESM. The model ability of
aging of snow under the glacial climate should be evaluated. On the
other hand, the radiative forcing by high dust load in the troposphere
acts for the surface warming surroundings of the Antarctica mainly
caused by the indirect effect of dust.