HR: 17:15h
AN: OS54B-06    [Abstracts]
TI: Numerical Model Simulations of Circulation over the Continental Shelf off Northern California
AU: * Kuebel Cervantes, B
EM: bkuebel@coas.oregonstate.edu
AF: College of Oceanic & Atmospheric Sciences Oregon State University, 104 COAS Admin Building, Corvallis, OR 97331 United States
AU: Allen, J
EM: jallen@coas.oregonstate.edu
AF: College of Oceanic & Atmospheric Sciences Oregon State University, 104 COAS Admin Building, Corvallis, OR 97331 United States
AB: The three-dimensional circulation on the continental shelf off northern California in the WEST (Wind Events and Shelf Transport) experiment region is studied using the primitive equation Regional Ocean Modeling System (ROMS). The simulations are performed with realistic topography and initial stratification in a limited-area domain with a high-resolution grid. Forcing consists of measured wind stress and heat flux values obtained during summer 2001. The general response shows a southward coastal upwelling jet of up to 1 m s$^{-1}$ and a weakening or reversal of currents inshore of the jet when upwelling winds relax. Model results are compared to WEST moored velocity and temperature measurements at five locations, to the CODAR region surface current observations, and to hydrographic measurements along shipboard survey lines. The model performs reasonably well, with the highest velocity correlations at the inshore mooring (40 m water depth) and below 70 m depth at the offshore moorings (90 m and 130 m water depth). The comparison of surface velocities with CODAR measurements shows good agreement in the mean velocity vectors and the first two EOF modes. The hydrography compares closely at the southern and northern edges of the survey region, with weaker correlations at the three interior survey lines. We examine the dynamics during an upwelling and subsequent relaxation event in May 2001 in which the WEST measurements show evidence of a strong flow response. Flow near Pt. Reyes during this event is complicated and the response to upwelling and relaxation north and south of Pt. Reyes is quite different. Analysis of term balances from both the three-dimensional and depth-averaged momentum equations help to clarify the event dynamics in different regions over the shelf.
DE: 4219 Continental shelf processes
DE: 4255 Numerical modeling
DE: 4500 OCEANOGRAPHY: PHYSICAL
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting