Seasonal current simulations for the western continental margin of Vancouver Island

Abstract

Two three‐dimensional finite element models, one diagnostic and one semiprognostic, are used to simulate summer and winter currents for the western continental margin of Vancouver Island, British Columbia. The calculations are forced (or nudged) with seasonal winds, climatological density fields, and elevation‐specified boundary conditions that have been adjusted via inversion to more accurately represent the California Undercurrent and estuarine flow in Juan de Puca Strait. Tides are included in the simulations in order to correctly represent turbulent mixing, bottom friction, and the contribution of tidal rectification. The seasonal model currents are shown to compare favorably with multiyear, low‐pass filtered current meter observations and to capture strong shears both vertically in Juan de Fuca Strait and horizontally and vertically across the continental shelf and slope. The tidal currents are more accurate than those computed with a previous three‐dimensional barotropic model.