A central California coastal ocean modeling study: 1. Forward model and the influence of realistic versus climatological forcing

We report on a numerical simulation of the California Current circulation using the Regional Ocean Modeling System model, focusing on the region of northern and central California during the 5-year period from 2000 to 2004. Unlike previous model studies of the California Current System, the present configuration is characterized by both realistic external forcing and a spatial domain covering most of the North American West Coast. Specifically, this configuration is driven at the surface by high-resolution meteorological fields from the Coupled Ocean-Atmosphere Mesoscale Prediction System and at the lateral open boundaries by output from the project Estimating the Circulation and Climate of the Ocean supported by the Global Ocean Data Assimilation Experiment. The simulation is evaluated favorably through quantitative comparisons with the California Cooperative Fisheries Investigations data set, satellite-derived sea surface temperature, and surface drifters-derived eddy kinetic energy. The impact of adopting realistic versus climatological surface forcing is demonstrated by comparing mean and mesoscale circulation characteristics. Realistic surface forcing qualitatively alters the seasonal cycle of the mean along shore jet and better reproduces the summer spatial structure and intensity of the eddy kinetic energy field along the central California coast.