Non-linear climatic response to the weakening of the Atlantic Meridional Overturning Circulation during glacial times

Abstract

The climatic response to the weakening of the Atlantic Meridional Overturning Circulation (AMOC) is investigated under glacial conditions representative of Heinrich Stadial 5 using a fully coupled Earth System Model (ACCESS-ESM1.5). We find that the climatic response to an AMOC slowdown or shutdown, respectively representing Dansgaard–Oeschger (D–O) and Heinrich stadials, is non-linear. Global mean temperature and precipitation anomalies increase linearly with an AMOC slowdown; however, crossing the threshold of AMOC shutdown results in non-linear and more complex atmospheric circulation and climate responses. The atmosphere partially compensates for the significantly reduced oceanic energy ..