Modeling studies of the effects of wind forcing and thermohaline gradientson the California Current System

This process-oriented study uses a high-resolution, multi-level, primitive equation model to study the combined effects of wind forcing and thermohali ne gradients on the ocean circulation of the California Current System (CCS ). The ocean circulation is generated by the model using a combination of c limatological wind stress forcing and thermohaline gradients. In the first experiment, the effects of thermohaline gradients alone are evaluated; in t he second experiment, previously conducted, the effects of wind forcing are isolated; while in the third experiment, the combined effects of wind forc ing and thermohaline gradients are investigated. The results from the combi ned experiment show that even though the effects of wind forcing dominate t he CCS, the additional effects of thermohaline gradients result in the foll owing: the seasonal development of a poleward surface current and an equato rward undercurrent in the poleward end of the model region; an onshore geos trophic component, which results in a temperature front and stronger surfac e and subsurface currents between Cape Mendocino and Point Arena; and a reg ion of maximum eddy kinetic energy inshore of similar to 125W between Cape Mendocino and Point Arena, associated with the temperature front. These mod el simulations are qualitatively similar to recent hydrographic, altimetric , drifter, and moored observations of the CCS. Published by Elsevier Scienc e Ltd.