Wind‐driven currents in a ‘wide’ narrow channel, with application to Douglas Channel, BC

This paper applies a structured grid, 3-Dimensional Regional Ocean Modeling System to examine wind-driven currents of an idealized stratified channel, representative of Douglas Channel, British Columbia, Canada, where the increased marine activities require an improved understanding of the physical oceanography. The surface along-channel elevation slope resulting from the wind stress is strongly affected by the surface stratification and can serve as a proxy for gauging surface stratification in operational systems. In the case of strong surface stratification, due to rotational effects an apparently narrow (width MUCH LESS-THAN length) channel can be dynamically wide with pronounced cross-channel variation. The thickness of the surface wind-driven layer is scaled using the thermal wind relation, which provides a scaling factor to estimate the thickness of the surface layer. This scaling factor is not restricted to the wind-driven flow and could be expanded to the surface mean estuarine outflow layers.