Circulation and Energetics of a Deep, Strongly Stratified Inlet

Abstract

The paper compares a theoretical model of steady flow in a strongly stratified inlet with the observed behavior of Knight Inlet, British Columbia. Some aspects of the behavior compare favorably with the theory and some aspects do not. Specifically, the model does well in the limit of small interfacial friction coefficient, which is surprising as the evidence presented by Long (1975) suggests that interfacial friction should dominate the flow. Long demonstrates that the circulation in inlets of this type should adjust to maintain the interfacial Froude number at unity near the mouth. In the paper we demonstrate that Knight Inlet is not apparently being controlled in this way.Computations of the amount of energy required to drive the circulation, the amount that can be extracted from the wind, and the amount that is being lost by the barotropic tides indicate that tidal interactions with the sill in Knight Inlet drive the mean circulation. The wind contributes little to the overall energy budget of Knight Inlet.Key words: Knight Inlet, circulation, dynamics, energetics, internal waves, turbulence, mixing processes, entrainment