The Strait of Georgia: functional anatomy of a coastal sea

Abstract

The physical oceanography of the Strait of Georgia, a large estuary on the coast of British Columbia, is reviewed in the light of recent observations and theoretical developments. The review focusses on a discussion of physical mechanisms rather than on a description of properties. The responses of the Strait to the dominant forcing processes, the tides, freshwater runoff, and atmospheric inputs, are described first. Interactions between these responses are then shown to give rise (or at least to influence) other phenomena such as fronts, deepwater renewal, and oceanic exchange processes. Recent observations of deep residual flows as well as theoretical efforts to explain their nature are also discussed. The present state of the understanding of dynamics is assessed against the requirements of predictive modeling; whereas high-frequency phenomena such as tides and upper layer dynamics are approaching an engineering level of predictability, low-frequency processes (water renewal, oceanic exchange, deep residual flows) remain inadequately documented, poorly understood, and unpredictable. Some suggestions are presented for future observational and theoretical research.