Impact of Greenland's Ice Loss on the Meridional Overturning Circulation

Ice loss from the Greenland Ice Sheet quadrupled in the last two decades and is projected to further increase. One important consequence of this ice loss is sea level rise. A second, largely overlooked consequence is the freshening of the waters of the Nordic Seas and subpolar North Atlantic and its potentially dramatic impact on the Atlantic's Meridional Overturning Circulation (AMOC). While models are beginning to address this question, the validity of these simulations is strongly limited by a lack of knowledge of how and where Greenland's meltwater enters the ocean. Explicitly, measurements from Greenland's glacial fjords show that the bulk of the meltwater is exported subsurface within glacially modified waters and not as a surface freshwater flux. At UiB, I propose to address this question in two steps. First, we will use new and existing data to track the spreading of Greenland's meltwater into the subpolar North Atlantic and the Nordic Seas. Second, we will use the results from phase 1 to develop appropriate forcing conditions for ocean models. This work will build on the expertise of Straneo, who has been leading efforts to understand glacier/ocean interactions in Greenland with that of Eldevik (AMOC modeling and data analysis in the Nordic Seas), Våge (convection in the subpolar North Atlantic and Nordic Seas/subpolar North Atlantic exchange) and Nisancioglu (ice sheet/ocean modeling and past changes on Greenland). It will also facilitate interactions between Norwegian scientists and the international network of scientists working on Greenland Ice Sheet/Ocean (GRISO - co-chaired by Straneo) and a large US-led international program to measure overturning in the Subpolar North Atlantic (OSNAP) that Straneo is involved in.