Sensitivities in modelling baroclinic currents and tides in the Strait of Georgia

Different types of internal wave and tide motion occur in the strongly stratified Strait of Georgia. Internal waves are disturbances in the interior of a stratified fluid that form in response to the restoring force of gravity. Like surface waves, internal waves can shoal and break and have important implications for mixing and distribution of nutrients in coastal systems. Using a baroclinic ocean model, we investigate the origins of internal tide motion in the Strait of Georgia waters. Upon evaluation of the model\u27s barotropic tidal currents, we find a reasonable match with observations and other models of this region. On the other hand, there are significant discrepancies between observed and modelled baroclinic and surface currents in the vicinity of the Fraser River. We discuss the sensitivity of the model\u27s baroclinic currents to representations of the Fraser River, and parametrizations of vertical viscosity, diffusivity, and bottom friction. Finally, we explore the fate of internal tide motions generated over the Strait of Georgia sill and their interaction with the strongly stratified surface layer