Tides and currents in Barkley sound and Alberni Inlet

Abstract

A vertically integrated tidal model of Barkley Sound has been developed as the first phase of a study of circulation and its interaction with juvenile salmon moving through Alberni Inlet and Barkley Sound to the Pacific Ocean. This model is an implementation of the three‐dimensional baroclinic model GF8 using a single layer, with a horizontal grid size of 400 m. Elevations and velocity boundary condition data for this model were obtained from an irregular grid finite element model of the west coast of Vancouver Island. The resulting barotropic tidal model was found to be stable, and produced tidal elevations in close agreement with observations. Modeled tidal currents at the location of a current meter morred in Imperial Eagle Channel agreed well with observations, to the extent that barotropic currents could be deduced in a simple manner from observations containing both barotropic and baroclinic modes. The next phase in the modeling program was the development of an upper layer baroclinic model, to resolve the sharp pycnocline separating the brackish surface layer in Alberni Inlet from the underlying denser water. Preliminary results from this model are also described, showing the influence of wind and freshwater inputs on the surface current pattern in both Alberni Inlet and Barkley Sound.

Keywords:

• tidal model
• upper layer model
• Barkley Sound
• Alberni Inlet