The poleward enhanced Arctic Ocean cooling machine in a warming climate.

As a cooling machine of the Arctic Ocean, the Barents Sea releases most of the incoming ocean heat originating from the North Atlantic. The related air-sea heat exchange plays a crucial role in both regulating the climate and determining the deep circulation in the Arctic Ocean and beyond. It was reported that the cooling efficiency of this cooling machine has decreased significantly. In this study, we find that the overall cooling efficiency did not really drop: When the cooling efficiency decreased in the southern Barents Sea, it increased in the northern Barents and Kara Seas, indicating that the cooling machine has expanded poleward. According to climate model projections, it is very likely that the cooling machine will continue to expand to the Kara Sea and then to the Arctic Basin in a warming climate. As a result, the Arctic Atlantification will be enhanced and pushed poleward in the future.