Minimal AMOC Impact in Alaska During the Younger Dryas

Abstract The Younger Dryas chronozone (YD), between ∼12,900 and 11,600 years ago, represents a climatically dynamic period in Earth's history that was defined by rapid millennial‐scale climate changes. The cause of the climate change during the YD is typically attributed to substantial meltwater flux into the North Atlantic, which weakened the Atlantic meridional overturning circulation (AMOC). However, it is unclear if the climate signal from periods of AMOC shutdown were truly global in nature. Here, by utilizing the transient iTraCE simulation, a coupled climate model simulation of the last deglaciation, we test if the climate in Alaska was strongly influenced by an AMOC forcing. We find no significant impact of a North Atlantic meltwater forcing on Alaska climate during the YD. However, we do find millennial‐scale climate changes concurrent with the YD. We argue that the millennial‐scale climate change in Alaska during the YD was driven by changes in the tropical Pacific mean state, which could have been mistaken for an AMOC forcing.