On the role of the unresolved eddies in a model of the residual currents in the central strait of georgia, B.C.: research note

Abstract

A depth-independent numerical model of the Juan de Fuca/Strait of Georgia system reproduces the broad structure of the observed depth-averaged residual circulation in the Central Strait of Georgia but underestimates its magnitude (Marinone and Fyfe, 1992). Here we present some new calculations based on a re-parameterization of the unresolved eddies in terms of “statistical dynamical tendencies” instead of the previous eddy-viscosity treatment. With the new parameterization, the simulated time-mean flow is closer to the observed circulation both in structure and magnitude. While not specifically designed to do so, the new parameterization also leads to a modest improvement in the low-pass filtered component of the flow. Based on these results, the depth-averaged residual currents in the region are conjectured to involve a four-way balance between the hitherto ignored effect of “statistical dynamical tendencies” and conventional tidal, atmospheric and buoyancy forcing. © Taylor & Francis Group, LLC.