Numerical simulations of a buoyancy-driven coastal countercurrent off Vancouver Island

Abstract

A three-dimensional prognostic numerical model has been developed to study the ocean circulation around Vancouver Island, British Columbia. In a series of simulations, the model is applied to examine the role of buoyancy forcing in the dynamics of the summer coastal countercurrent found off the west coast of Vancouver Island. The forcing is provided by the Fraser River discharge into the Strait of Georgia. An estuarine circulation establishes itself in Juan de Fuca Strait, from which a distinctive right-bounded current is formed and advances along the coast. Sensitivity studies are conducted to determine the robustness of this current to initial conditions, opposing wind, enhanced vertical mixing, and grid resolution. Finally, various characteristics of the numerically modeled coastal flow are compared with observations.