Impact of Dust on Climate and AMOC During the Last Glacial Maximum Simulated by CESM1.2

While the impact of dust on climate and Atlantic Meridional Overturning Circulation (AMOC) during the interglacial period such as the mid-Holocene has been studied extensively, its impact during the glacial period is unclear. Here we investigate how the climate and AMOC would change if there had been no dust during the Last Glacial Maximum. Model simulations show that the dust removal leads to a global cooling of over 2.4 degrees C and a weakening of AMOC by similar to 30%. Such temperature change is opposite in sign to that for the MH. The cooling is attributed to the increase of snow and ice albedo and weakening of AMOC when dust is removed, and is amplified through a positive feedback between sea ice and AMOC. Our results indicate that the climate and AMOC are more sensitive to dust change during the glacial than the interglacial period.