Heat Transport by Mesoscale Eddies in the Norwegian and Greenland Seas

Abstract

AbstractOcean vortices are an important regional agent of water transport and cross‐frontal exchange. This study is a first attempt to compare statistics of 3D properties of mesoscale eddies over the Norwegian and Greenland Seas. Results suggest that eddies in the central Greenland Sea are less intense, have smaller vertical extent and much smaller heat anomalies in their cores compared to eddies in the Lofoten Basin of the Norwegian Sea. In addition, these results suggest a relatively small inter‐basin eddy exchange. The large‐scale pattern of eddy translations shows that eddies cyclonically skirt the Norwegian‐Greenland region. There is also a regional cyclonic pattern in the Lofoten Basin with a consistent signature of eddy merger in the northern part of the basin. We confirm that eddies generated from the Norwegian Atlantic Slope Current (NwASC) have a significant effect on the amount of heat the NwASC brings to the Arctic. The heat lost from the NwASC between the Svinoy and Sorkapp sections associated with the westward eddy heat transport translates to 70 ± 23 TW, 90% of which occurs in the Lofoten Basin. This accounts to 35% of the heat advected by the NwASC across the Svinoy section and is comparable with the heat loss in the Barents Sea. Interannual variability of the heat flux due to a change in the number of generated eddies is relatively small (∼10 TW). Nevertheless, our estimates suggest that, by varying temperature of their cores, the generated eddies can effectively damp temperature anomalies that propagate north along the NwASC.