Impact of Dust on climate and AMOC during the Last Glacial Maximum
Simulated by CESM1.2
Abstract
While the impact of dust on climate and Atlantic Meridional Overturning
Circulation (AMOC) during the interglacial period such as the
mid-Holocene (MH) 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
(LGM). Model simulations show that the dust removal leads to a global
cooling of over 2.4 °C and a weakening of AMOC by ~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.