DEVELOPMENT, APPLICATION AND EVALUATION OF A REAL-TIME, DATA- ASSIMILATIVE COASTAL OCEAN FORECASTING SYSTEM FOR THE SOUTHERN CALIFORNIA BIGHT
TITLE:
DEVELOPMENT, APPLICATION AND EVALUATION OF A REAL-TIME, DATA- ASSIMILATIVE COASTAL OCEAN FORECASTING SYSTEM FOR THE SOUTHERN CALIFORNIA BIGHT
DATE:
Friday, March 19th, 2010
TIME:
3:30 PM
LOCATION:
GMCS 214
SPEAKER:
John D. Farrara,
Jet Propulsion Laboratory
California Institute of Technology, Pasadena, CA and
Joint Institute for Regional Earth System Science and Engineering,
UCLA
ABSTRACT:
The development, application and evaluation of a data-assimilative coastal ocean forecast system based on the Regional Ocean Modeling System (ROMS) will be presented. This ROMS configuration consists of a single domain covering the southern California coastal ocean from Santa Barbara to San Diego at a resolution of 1 km and uses atmospheric forcing produced by a regional atmospheric model at 4km resolution. In-situ glider, satellite and coastal HF radar measurements that are available in near real-time are assimilated into ROMS using a novel multi-scale, incremental 3-dimensional variational data assimilation scheme with an assimilation window of six hours. The product of this assimilation, the ROMS nowcast (or analysis), is generated at 03, 09, 15, and 21 GMT. In addition, a 48 hour forecast is performed each day using the 15 GMT nowcast as the initial condition. All nowcast and forecasts images and the data are delivered to end-users via the web at http://ourocean.jpl.nasa.gov/SCB. The system has been running in real-time since April 2007.
Selected comparisons of nowcast fields with both assimilated (routine observations) and independent measurements (from field experiments such as the RaDyO experiment in the Santa Barbara Channel) show very good agreement of the observed temperature and salinity values with the co-located ROMS-analyzed values. The forecasts have also been analyzed to assess their skill. It is found that anomaly correlations for the surface currents and temperatures are larger than 0.6 for 48 hour forecasts, significantly larger than those of a persistence forecast. Consistent with this, the forecast RMS errors in the surface fields are smaller than those of a persistence forecast. In addition, the results suggest that the system is capable of realistically reproducing mesoscale eddies observed within the Santa Barbara Channel.
HOST:
Jose Castillo
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