Simulations of Heinrich Events in a coupled ocean-atmosphere-sea ice model

[1] Between 20 and 80 kyr ago several cooling cycles occurred in the Northern Hemisphere which culminated in a discharge of icebergs into the North Atlantic. These so called ‘‘Heinrich Events’’ (HEs) were followed by an abrupt shift to a warmer climate. Here we use a coupled ocean-atmosphere-sea ice model to study the response of the climate system under glacial conditions to a hypothetical HE. The HE is simulated by meltwater discharges and combined changes in land albedo and ice sheet topography mimicking a break-up of a considerable part of the Laurentide ice sheet. Despite very different initial strengths of the overturning circulation in the Northern Hemisphere, the model response to the HEs is qualitatively similar. A warming of ocean and atmosphere temperatures due to the topography/albedo changes is simulated after the iceberg discharge. North Atlantic Deep Water (NADW) formation drops and reestablishes due to the meltwater event.