HR: 09:55h
AN: OS11O-06    [PDF]
TI: Coastal Upwelling Response to Atmospheric Wind Forcing along the Pacific Coast of the United States.
AU: * Penven, P
EM: penven@atmos.ucla.edu
AF: IGPP, UCLA, 405 Hilgard Avenue, Los Angeles, CA 90095-1567 United States
AU: McWilliams, J C
EM: jcm@atmos.ucla.edu
AF: IGPP, UCLA, 405 Hilgard Avenue, Los Angeles, CA 90095-1567 United States
AU: Marchesiello, P
EM: patrickm@atmos.ucla.edu
AF: IGPP, UCLA, 405 Hilgard Avenue, Los Angeles, CA 90095-1567 United States
AU: Chao, Y
EM: yc@pacific.jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AB: Wind stress is recognized as the most important driving force for coastal upwelling. Along the West Coast of the United States, although wind stress is mainly directed towards the equator, i.e. favorable to upwelling, it shows important spatial and temporal variations. A model of the Central California Upwelling System has been developed to assess the ocean response to different wind forcings. A nesting capability has been integrated into the Regional Ocean Modeling System (ROMS) to obtain local solutions at high resolution while preserving the large-scale circulation at affordable computational cost. It has been applied to a domain that covers the central upwelling region of the United States West Coast, around Monterey Bay, embedded into a domain including the whole US Pacific Coast. Long term simulations (10 years) have been conducted to get yearly cyclic statistical equilibria. Several simulations are performed, forced by different monthly mean wind stress climatologies: COADS, NCEP, QuickSCAT and COAMPS. The spatial sampling of these data-sets ranges from more than 100 kilometers for COADS and NCEP to 9 kilometers for COAMPS. While on the large scale these winds are relatively similar, they show important variations in the Coastal Transition Zone. In particular, COAMPS winds present strong and narrow gradients in the near-shore region which are not resolved by the other products. The model experiments show large sensitivities of coastal upwelling and even large-scale circulation to the spatial structure of the wind forcing at intermediate scales (tens to hundreds of kilometers).
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4255 Numerical modeling
DE: 4279 Upwelling and convergences
DE: 4516 Eastern boundary currents
DE: 4528 Fronts and jets
SC: OS
MN: 2002 Ocean Sciences Meeting