The Influence of Bottom Topography on the Stability of Jets in a Baroclinic Fluid

Abstract

The stability of a two-layer model is analyzed using a numerical method taking into account the effect of bottom topography. A jet in geostropic equilibrium exists in the upper layer and baroclinic instability may occur. It is found if the bottom topography has a large amplitude relative to the total depth, that it has a destabilizing rather than a stabilizing influence. Applying the model to the Gulf Stream, it is found that the most unstable disturbances, corresponding to the basic flow upstream from Cape Hatteras, are markedly different in wavelength and period from those corresponding to the basic flow downstream from Hatteras. The baroclinic disturbances in the model are consistent with the limited observational evidence on momentum transfer by Gulf Stream eddies.