Session: Glacial Climates (LGM, Last deglaciation, Ice sheet uncertainties, Glacial-interglacial cycles)
Author: Takashi Obase / email@example.com / AORI, University to Tokyo
Co-author: Ayako Abe-Ouchi, AORI, University to Tokyo;
During the last deglaciation, a major global warming was punctuated by several abrupt climate changes, likely related to Atlantic Meridional Overturning Curculation (AMOC). A transient simulation from the Last Glacial Maximum (21,000 years ago) to Bolling-Allerod (BA, 14,000 years ago) is conducted using an atmosphere-ocean coupled general circulation model. Changing insolation, greenhouse gas concentrations and glacial meltwater fluxes are applied based on reconstructions. An abrupt recovery of the AMOC occurred at around the period of BA, even under the glacial meltwater flux that is equivalent to a sea level rise of approximately 5 meters in 1,000 years. The simulated transition of Greenland climate occurs in approximately 100 years, which is consistent with reconstructions. The results indicate that the increasing summer insolation and greenhouse gas concentration could trigger an abrupt recovery of the AMOC without large fluctuations of glacial meltwater flux in the North Atlantic in MIROC AOGCM.