Pressure Compensation and the Bottom Boundary Layer

Abstract

It is an observed characteristic of oceans that velocities and horizontal pressure gradients are larger new the ocean surface than they are in deeper water. This is conventionally labeled ?pressure compensation? whereby baroclinic structure, comprising sloping isopycnal surfaces, is adjusted so that surface pressure gradients are reduced in deeper water. In this paper, a two-dimensional flow in a channel is numerically modeled to demonstrate the baroclinic adjustment process and its relationship to the bottom boundary layer. A simple analytical model is also developed and defines the timescale of the adjustment process.