From small whirls to the global ocean - how ocean eddies may govern the response of the Atlantic Meridional Overturning Circulation to high-latitude climate change, spreker: Caroline Katsman, TU Delft

In the marginal seas of the North Atlantic Ocean (Labrador Sea, Irminger Sea, and Greenland-Iceland-Norwegian Seas), surface waters are cooled by the atmosphere, mix vertically with waters below, sink, and return southward at depth.

This three-dimensional ocean circulation, quantified by means of the Atlantic Meridional Overturning Circulation (AMOC), transports vast amounts of heat northward and is of paramount importance for Earth’s climate. Climate models project a significant decline of the AMOC by the year 2100, with a regional sea level rise of several tens of centimeters along the Dutch coast as one of the consequences. In our research group we investigate where the North Atlantic dense waters sink, and what factors control this location and the magnitude of the downward mass transport. In particular, we focus on the role of small-scale eddies for this process, as these are known to affect the dense water formation, and are hypothesized to play an important role for the sinking and spreading of convectively-formed dense waters. If this is the case one may question the validity of projections of future AMOC changes, as the current generation of climate models does not have sufficient resolution to resolve small-scale eddies.

In this talk, I will show the first results of this project, in which we combine the analysis of global-scale simulations at eddy-resolving resolution and (climate model-like) non eddy-resolving resolution with regional high-resolution process studies.