Atlantic meridional overturning and climate response to Arctic Ocean freshening

The global deglaciation event that followed Last Glacial Maximum was punctuated by a sequence of rapid climate changes. This began with the Laurentide Ice Sheet derived calving event called Heinrich Event 1, continued with the Bølling‐Allerød warming that occurred synchronously with meltwater pulse 1a, and was in turn followed by the Younger‐Dryas abrupt return to cold conditions. Although it has long been believed that these events are consequences of the response of Atlantic meridional overturning circulation to freshwater inputs, it has always been assumed that these inputs were applied directly to the Atlantic Ocean itself. We address the question of how the Atlantic meridional overturning circulation would have responded to the recently hypothesized addition of freshwater into the Arctic Ocean at the time of onset of the Younger‐Dryas, and thereby demonstrate that this response is essentially identical to the response to North Atlantic freshening.