ACCESS-ESM1.5 model simulations of AMOC shutdown during Heinrich 5: impacts on Southern Hemisphere hydroclimate

The Last Glacial Period was characterised by repeated millennial-scale climate oscillations which are commonly referred as the Dansgaard-Oeschger (D-O) variability. During some of the coldest D-O stadials, massive icebergs discharged into the North Atlantic Ocean leading to a substantial weakening of the Atlantic Meridional Overturning Circulation (AMOC). These events are known as Heinrich events. In this study, we perform North Atlantic freshwater hosing experiments under 49 ka boundary conditions to simulate Heinrich 5 using the Australian Earth System Model ACCESS-ESM1.5 (CMIP6/PMIP4 model). We investigate the Southern Hemisphere and Australian climate response to an AMOC shutdown. The simulated temperature and precipitation changes are compared with available proxy reconstructions of Heinrich stadials, with a focus on the Southern Hemisphere. These idealised simulations provide insight into the processes linking changes in North Atlantic climate to the Southern Hemisphere, and particularly the Australian region.