WIND-DRIVEN DEPTH-AVERAGED CIRCULATION IN QUEEN CHARLOTTE SOUND AND HECATE STRAIT

We develop a wind-driven depth-averaged model of the circulation on the continental shelf around the Queen Charlotte Islands. The model captures a major feature of the winter current-meter observations: a flow in Moresby Trough against the direction of the prevailing winds. Moresby Trough is a steep submarine canyon cutting across the shelf from the Pacific Ocean to the mainland. The flow patterns revealed by simulated drifters lead to four generalizations about the depth-averaged, wind-driven flow: (1) the flow is subject to strong topographic steering, (2) the exchange between Queen Charlotte Sound and the Pacific Ocean is limited to small regions near Cape St James and Cape Scott, (3) the exchange between Queen Charlotte Sound and Hecate Strait is controlled by Moresby Trough, and (4) the observed outflows past Cape St James are not explained by the dynamics of this model.