The Northeast Coastal Ocean Forecast System (NECOFS) is an integrated atmospheric-ocean model system designed for the northeast US coastal region covering a computational domain from the south of the Long-Island Sound to the north of Nova Scotian Shelf. The system include 1) meso-scale meteorological models WRF (Weather Research and Forecasting model) and MM5 (fifth-heneration NCAR/Penn State non-hydrostatic mesoscale model); 2) the unstructured grid Finite-Volume Coastal Ocean Model with configuration for the Gulf of Maine/Georges Bank /New England Shelf (FVCOM-GOM); 3) the unstructured grid surface wave model (UG-SWAN); 4) the FVCOM-based unstructured grid sediment model and 5) the generalized biological models. At the current stage, the forecast system is build based on WRF, MM5 and FVCOM.
WRF and MM5 has been validated by hindcast experiments from 1979 to present. The WRF and MM5 used in the forecast system is modified versions with implementation of theTOGA COARE heat flux algorthm (Chen et al. 2005). Both WRF and MM5 predict 3 days's forecast fields of surface wind velocity, air pressure, air temperature, net surface heat flux, shortwave irradiance, longwave radiation, sensible and latent heat fluxes. A comparison was made between WRF and MM5 and no significant difference was found. WRF seems to providee a more accurate wind direction than MM5, but it does not always true. Because of it, we include both WRF and MM5 to provide two ensemble fields of the meteorological field in this region.
It is widely recognized that the Planetary Boundary Layer (PBL) pays a critical role in mesoscale weather variablity. There are a variety of PBL models available in MM5 and WRF. We have tested all these models in MM5 and found out Medium-Range Forecast (MRF) seems to work the best for the Gulf of Maine region (Chen et al. 2005) in both good and bad weather conditions. Instead of providing the ensemble fields predicted using various PBL, we only selected MRF-predicted field for our prediction system to provide a more realistic meso-scale meteorological fields (based on the known uncertainty from over 20 years of hindcast simulation).
FVCOM-GOM has been also validated by hindcast experiments from 1995 to present. By comparing with tidal data, water temperature and current data, this model is capable of reproducing accurately both tidal and subtidal motions in the Gulf of Maine/Georges Bank/New England Shelf regions. The hindcast results can be viewed in " Gulf of Maine/Georges Bank", Nantucket Sound, and Mass Bay pages. FVCOM is driven by WRF and MM5 to provide 3-days forecast fields of water temperature, salinity, and currents. The predicted river discharges and upstream hydrographic conditions at open boundaries are specified for the forecast operation. The 3-day forecast is updated daily with hindcast meteorological fields and available river discharge and open boundary conditions.
UG-SWAN is driven by WRF and MM5 forecast winds in the FVCOM domain and NAM wind forecast in the Atlantic Ocean region. Significant wave heights are displayed
We are still working on improving the NECOFS. FVCOM-GOM results displayed here are based on the 2nd- generation FVCOM-GOM. At very soon, we will upgrade it to our 3rd-generation FVCOM-GOM with higher resolution at the slope and with capability of nesting automatically to the sub coastal domain along the coast.
NECOFS is built as a product of the Northeast Regional Coastal Ocean Observation System (NERCOOS) Program with supports from NOAA-NERCOOS, SMAST-Fisheries Program, and NSF/NOAA GLOBEC/Georges Bank Program, MIT Sea Grant Program.
|
