Representing eddy stress in an Arctic Ocean model

Abstract

Experiences with a number of ocean models have shown Arctic Ocean circulation to be quite dependent upon assumptions about eddy stresses. A key difference is between assuming that subgrid eddies act as friction and assuming that eddies act to generate entropy, propelling mean flows (sometimes called “neptune”). Fisheries and Oceans Canada is developing global ocean and sea ice modeling after Nucleus for European Modeling of the Ocean (NEMO). We have modified NEMO to include neptune as an alternative to friction. Consistent with previous modeling studies, our results show marked impacts. Neptune supports narrow cyclonic midwater and deepwater currents around the peripheries of Arctic basins. Neptune also induces two‐way flows through channels in the Canadian Archipelago and limits the width of the ice tongue exiting at Fram Strait.