A Modeling Study of the Three-Dimensional Continental Shelf Circulation off Oregon. Part II: Dynamical Analysis

Abstract

Abstract Sixty-day simulations of the subinertial continental shelf circulation off Oregon are performed for a hindcast study of summer 1999. In Part I, the model results are shown to compare favorably with in situ currents and hydrographic measurements obtained from an array of moored instruments and field surveys and high-frequency radar–derived surface currents. In this paper, the modeled three-dimensional, time-varying circulation and dynamical balances are analyzed, providing a detailed synoptic description of the continental shelf circulation off Oregon for summer 1999. The circulation is clearly wind driven and strongly influenced by alongshore variations in shelf topography. In the region of the coast where the alongshore topographic variations are small the upwelling circulation is consistent with standard conceptual models for two-dimensional across-shore circulation. In the regions where the alongshore topographic variations are greater, the upwelling circulation is highly three-dimensional. Ov...