Arctic Ocean change heralds North Atlantic freshening

Abstract

A large pool of freshwater formed of ice and runoff is hosted by the Arctic Ocean. It exits through the Canadian Archipelago and Fram Strait to enter the North Atlantic deep water production regions. Using a numerical model and observations we trace a strong freshwater release to subpolar waters in the mid-1990s. In contrast to the ice export driven 1970's 'Great Salinity Anomaly' its source was a large additional liquid freshwater release from the Arctic Ocean. In fact it was a consequence of a change of the Arctic Ocean's thermohaline structure in response to the very intense North Atlantic Oscillation in the early 1990s. Our results show a strong link of large-scale Arctic Ocean changes with the freshwater flux to subpolar waters. Copyright 2005 by the American Geophysical Union.