Constraints on exchanges in the Arctic Mediterranean—do they exist and can they be of use?

Extensive changes have been reported from the Arctic Mediterranean. The ice cover is retreating, the temperature in the Atlantic layer has been increasing, the salinity in the upper layers shows large variations and deep waters in the Greenland Sea have become warmer and more saline. These changes all appear externally forced; by the radiation balance, by the atmosphere, and by ocean advection. The question arises—are there processes inherent to the Arctic Ocean, which can constrain changes induced by external forcing? Three features are examined; the storage and export of liquid freshwater in the upper layers, the heat loss of the Atlantic water encountering sea ice and the possibility to define a salinity separating the two roles of the Arctic Mediterranean, as estuary and as concentration basin. If the freshwater outflow in the upper layer is rotationally controlled, the liquid freshwater storage and export only depend upon the freshwater input. The melting rate of sea ice is affected both by the heat transport and by the temperature of the inflowing Atlantic water. A salinity separating the estuarine and the deep-water circulation is proposed depending upon the salinity and the temperature of the Atlantic water as it encounters sea ice.