The Prediction of Wind-Driven Coastal Circulation
PIs: John Allen and Jack Barth, OSU
Academic Partners:
Government Partners:
Industrial Partners:
COAS, OSU, Corvallis, OR (Allen, Barth, Boyd, Caldwell, Egbert, Huyer, Kosro, Levine, Miller, Moum, Samelson, Skyllingstad)
NOAA, NMFS, Newport, OR (Peterson)NOAA, ETL, Boulder, CO (Harlan, Wilczak)
CODAR Ocean Sensors, Los Altos, CA (Barrick, Lipa)Ocean Imaging, Solana Beach, CA (Svejkovsky)
OSU NOPP
Goal: Develop nowcast and forecast systems for wind-driven coastal ocean flow fields (alongshore coastal jets, upwelling and downwelling fronts, eddies, surface and bottom boundary layers)
Approach:•High-resolution coastal ocean and coastalatmospheric models
•Data assimilation
and bio-optics
•land-based coastal radar•moorings•turbulence profiling•atmospheric profiling•SeaSoar and MiniBAT hydrography
•Observational program
Barth, Kosro•wind-driven upwelling separated by wind relaxation events•upwelling over the shelf, broadening over the submarine banks•subsurface thermal features influenced by submarine bank topography
OSU-NOPP: Ocean Observations
•Land-based coastal radar (CODAR)surface velocities
•Alongshore jet following bottomtopography and intensified over thesubmarine banks
Kosro, Harlan
OSU-NOPP: Ocean Observations
OSU-NOPP: Atmospheric Model
Samelson, Skyllingstad, Wilczak
•mean and variable alongshore wind stress increases by a factor of 3-4 from north to south•intensification near Cape Blanco at 43N
OSU-NOPP: Atmospheric Model
Samelson, Skyllingstad, Wilczak
•atmospheric model provides useful estimates of
Model (solid) vs. buoy (dashed) wind stressModel minus buoy surface air temperature (solid) vs. alongshore wind stress (dashed)
wind stress•ocean upwelling evidently modifies coastal surface
air temperature by 1-5 degrees C over time scalesof 1-2 days
(Model SST is from large-scale analysis that does not resolve upwelling response.)
OSU-NOPP: Coastal Ocean Model
With spatially uniform winds With spatially varying winds
•Results with spatially varying wind stress forcing are qualitatively and quantitatively closer to observations
Modeled (solid) vs. observed (dashed) alongshelf currents at 20m
(top) with spatially uniform winds(bottom) with spatially variable winds
Allen, Gan(Moored observations: Levine, Kosro, Boyd)
OSU-NOPP: Data Assimilating Coastal Ocean Model
Oke, Allen, Miller, Egbert, Kosro
wind
observedvelocity
withassimilation
modeled(no data)
•Land-based radar velocities assimilated into a primitive equation ocean circulation model•velocity correlations between observations and the data-assimilating model substantially improved
over a model with no assimilation
•Data-assimilating model surface temperature maps capture observed broadening of upwelling
region over Heceta Bank
1998