Resdual currents in the central strait of Georgia, C

Abstract

A depth‐independent numerical model of the central Strait of Georgia is used in an attempt to reproduce the observed depth‐averaged residual circulation. The observed depth‐averaged mean (i.e. time‐averaged) residual circulation is characterized by a cyclonic eddy in the velocity field of about eight kilometres in diameter. As far as we know this is the only eddy of its kind in the central Strait of Georgia. The model reproduces the location and scale of the observed mean residual but significantly underestimates the magnitude of the velocity. The time‐dependent part of the observed depth‐averaged residual (which is as energetic as the mean) is dominated by oscillations in the fortnightly and monthly bands. This too is true of the modelled time‐dependent residual; however, once again the magnitude of the velocity is significantly underestimated. Bearing in mind the limitations of the model in reproducing the observed residual in all of its aspects, various diagnostic analyses have been performed with the aim of revealing the mechanism(s) maintaining the observed residual. Further to this an analytical model has been used to elucidate the role of topographic and tidal current interactions in the generation of the model residual. © 1992 Taylor & Francis Group, LLC.