Extended Abstract (412K)J1.3
An ocean forecasting system for the east coast of Canada
PAPER WITHDRAWN
Charles C. L. Tang, Bedford Insitute of Oceanography, Dartmouth, NS, Canada; and B. M. DeTracey
An ocean forecasting system has been developed at Bedford Institute of Oceanography (BIO) to provide daily forecasts of surface currents, waves, tides and sea-ice in the coastal waters of eastern Canada including the Labrador Shelf, N.E. Newfoundland Shelf and the Grand Banks. The system implements three separate models - a coupled ice model and Princeton Ocean Model (POM), a Grand Banks tide model and a spectral surface wave model. The ice/ocean model covers the entire Labrador Sea and its surrounding shelves. The forcing fields are computed from six-hourly forecast meteorological parameters provided by Canadian Meteorological Service. Seasonal water temperature and salinity are specified at the open boundaries, and are used to set the initial conditions of the model. Sea surface elevation at the open boundaries are prescribed in such a way that the resulting volume transports are consistent with observation. In particular, the volume transport into the Labrador Sea south of Greenland is set at 35 Sv. Sea-ice is coupled to POM using the coupling scheme of Mellor and Kantha. The ocean model is run continuously. Ice concentration and thickness are updated every day at -24 hours forecast time with daily digital ice maps provided by Canadian Ice Service. The wave model covers a large part of the North Atlantic, approximately 20ºN to 65ºN, 80ºW to 20ºW. Sea-ice areas are treated as land if the ice concentration and thickness are greater than 70% and 0.10m respectively. Tidal constants used to compute tidal elevation and tidal currents are generated from the three-dimensional tide model of Han. The model covers the Grand Banks, and includes the major semidiurnal (M2 , S2 , N2) and diurnal (K1 , O1) tides. Tidal elevations are specified at the open boundary on the basis of Petrie's model output and satellite altimetric measurements. The model results have been validated with available water level and current data from coastal tide gauge and offshore bottom pressure gauge stations, and moored current meters. Surface currents are represented by the sum of currents from the ice/ocean model averaged over the top 10 meters, and tidal currents from the tide model. They are plotted as two-day trajectories. Selected forecast results are displayed at BIO's website at http://www.mar.dfo-mpo.gc.ca/science/ocean/icemodel/ice_ocean_forecast.html. The forecasting system has been automated and run unattended. All forecasts start at 1200 UTC for a maximum period of 48 hours.
Joint Session 1, Estuarine and Coastal Ocean Forecasting-Joint Session with ECM and ERF (Please note some presentation times have been changed from the preliminary program published)
Wednesday, 7 November 2001, 9:00 AM-4:21 PM
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