The Influence of Viscous Boundary Layers on Transient Motions in a Stratified Rotating Fluid. Part II.

Abstract

The response of an unbounded ocean to circularly symmetric time varying wind stresses is analyzed. A continuously stratified ocean is first considered. The model includes bottom friction, but the Coriolis parameter is a constant. It is shown that in a stratified ocean both barotropic and baroclinic currents are generated by wind stresses. The barotropic current, however, has its amplitude limited by bottom friction, so that the baroclinic mode dominates for long period forcing. A simple analytic approximation to the depth dependence of static stability in the oceans is introduced and shown to give more realistic results than a constant static stability model. A two-layer model including both a variable Coriolis parameter and bottom friction is analysed. This simple model indicates that both bottom friction and the variation of the Coriolis force enhance the baroclinic mode.