A Primitive Equation Model Simulation of Eddies in the Norwegian Coastal Current

Abstract

Abstract A recent paper by Ikeda, Johannessen, Lygre and Sandven applying a two-layer quasi-geostrophic model to the growth of eddies in the Norwegian Coastal Current contains the comment that a more appropriate model may be a continuously stratified primitive equation model. Such a model is applied in this note to the same problem with similar initial conditions. The closeness of the results supports both models and demonstrates that the simpler model contains the important physics determining eddy growth, although it does not include outcropping of the isopycnals. The present model can be run in a frictionless mode, and the effect of reasonable values of friction is shown to be small. The effect of an Atlantic inflow with compensating outflow in the northern part of the Norwegian Trench is confined mainly to this region and causes the eddies to be pushed towards the coast by the topographically steered cross-trench flow.