ON THE ROLE OF THE UNRESOLVED EDDIES IN A MODEL OF THE RESIDUAL CURRENTS IN THE CENTRAL STRAIT OF GEORGIA, BC

A depth-independent numerical model of the Juan de Fuca/Strait of Geor gia system reproduces the broad structure of the observed depth-averag ed residual circulation in the Central Strait of Georgia but underesti mates its magnitude (Marinone and Fyfe, 1992). Here we present some ne w calculations based on a re-parameterization of the unresolved eddies in terms of ''statistical dynamical tendencies'' instead of the previ ous eddy-viscosity treatment. With the new parameterization, the simul ated time-mean pow is closer to the observed circulation both in struc ture and magnitude. While not specifically designed to do so, the new parameterization also leads to a modest improvement in the low-pass fi ltered component of the flow. Based on these results, the depth-averag ed residual currents in the region are conjectured to involve a four-w ay balance between the hitherto ignored effect of ''statistical dynami cal tendencies'' and conventional tidal, atmospheric and buoyancy forc ing.