Response of Total and Eddy Kinetic Energy to the recent spin-up of the Beaufort Gyre

Camille Lique, Laboratoire d'Océanographie Physique et Spatiale, IUEM, Plouzané, France, Heather Regan, NERC British Antarctic Survey, Cambridge, United Kingdom; IUEM Institut Universitaire Européen de la Mer, Laboratoire d'Oceanographie Physique et Spatiale, Plouzané, France, Gianluca Meneghello, Massachusetts Institute of Technology, Cambridge, MA, United States and Claude Talandier, CNRS, Laboratoire d'océanographie physique et spatiale, Plouzane, France
The Beaufort Gyre in the Arctic Ocean has spun up over the past two decades in response to change of the wind forcing and sea ice conditions, accumulating a significant amount of freshwater. In this talk, we will use results from a simulation performed with a high-resolution, eddy resolving model in order to provide a detailed description of the total and eddy kinetic energy, and their response to this spin up of the gyre. On average and in contrast to the typical open ocean conditions, the levels of mean and eddy kinetic energy are of the same order of magnitude, and the eddy kinetic energy is mostly intensified along the boundary and in the subsurface. In response to a strong input of momentum at the surface in 2007-2008, the mean kinetic in the gyre doubles and this new state is sustained afterwards. In contrast, the eddy kinetic energy does not increase significantly, because the isopycnals are able to flatten and the gyre expands outwards, reducing the potential for baroclinic instability. We will discuss the potential implications of our results for understanding the mechanisms at play for equilibrating the Beaufort Gyre and the variability and future changes of the Arctic freshwater system.