The coastal ocean is separated from the deep ocean by a steep continental slope. Due to the flow dynamics, this slope acts as a boundary to exchange between the two oceans. Exchange does occur but it much less than one would expect. We are studying the role of submarine canyons (which indent the continental slope) on this exchange. During summer southward current regimes, the canyons on the west coast of Vancouver Island can produce about as much cross-shelf-break exchange as the direct wind-driven upwelling. We have used numerical models, laboratory models, field observations and analytic scaling analysis. Numerical models have difficulty with the combination of steep topography, stratification and vertically sheared flow.

Our research is switching focus from the most common, relatively short canyons to long canyons (such as Juan de Fuca Canyon) which have a disproportionate cross-shelf flux.

Topography can also play an important role in atmospheric dynamics. In collaboration with D. Steyn, we are looking at upslope flows on sun-drenched mountains. Strong upslope winds occur and can ventilate pollutants from the valley (eg Vancouver and the North Shore mountains). Our role is laboratory modelling and analytic scaling analysis to investigate the basic dynamcis and to provide test cases for numerical models.

I have become convinced of the important role for physical oceanographers in piecing the puzzle of physical effects on biology in the ocean. Working in collaboration with chemists and biologists we are modelling the effect of physical factors on ecosystems and carbon transport. Published contributions include the role of advection and horizontal convergence in zooplankton exchange and aggregation around submarine canyon and detailed acoustical observations of the diel migration of zooplankton and the effect of their predators on their migration.