On a modified arrested topographic wave in Fram Strait

Abstract

The bottom geostrophic flow in Fram Strait is explained in terms of a modified arrested topographic wave model. The model is based on a combination of the vorticity balance between the topographic vortex stretching and the bottom Ekman pumping due to liner friction with a relation between the bottom flow and the bottom pressure gradient over a sloping bottom. Such a combination emphasizes a dynamical relevance of along-isobath density variations at the bottom. Using an inverse solution based on the hydrographic data from the MIZEX 84 experiment, it is shown that the along-isobath bottom density variations should be dynamically important, for example, in the East Greenland Current. A relatively high correlation between an along-isobath distribution of the bottom geostrophic flow and the bottom density is reported for that current. The density variations identified in the data should be able to drive a bottom geostrophic flow with a magnitude consistent with the inverse solution and observations.