Marine Ecosystem Dynamics Modeling Laboratory

Meterological Forecast Model System (MM5/WRF)

Currently we are running two separate meteorological models, the fifth-generation mesoscale regional weather model (MM5) developed by NCAR/Penn State (Dudhia et al., 2003) and the Weather Research and Forecasting (WRF) model. Both models feature nonhydrostatic dynamics, terrain-following sigma-coordinate, variable domain and spatial resolution, multiple grid nesting, 4-D data assimilation, and several planetary boundary layer (PBL) modules to represent turbulent mixing over the ground and ocean (Grell et al., 1994). They use NCAR/NCEP or ETA weather model fields as initial and boundary conditions with two-way nesting capability, and can provide continuous hindcasts and three-day forecasts. We have used both MM5 and WRF to construct a surface weather hindcast and forecast system for fishery studies in the GoM/GB (Chen et al., 2005b). These models are configured with a “regional” domain (covering the Northeast U.S.) and a “local” domain (covering the Scotian Shelf/GoM/GB/New England Shelf) with horizontal grid spacing of 30 and 10 km respectively , and 31 sigma levels in the vertical with finer resolution in the PBL. 

To improve the model-based surface wind stress and heat flux estimates, we employ the COARE 2.6 bulk algorithm (Fairall et al, 1996, 2003) for the air-sea fluxes and insolation and cloud cover data from the International Satellite Cloud Climatology Project for the radiative fluxes, and all coastal NDBC and C-MAN surface weather data available in the local domain are incorporated through 4-D data assimilation.

Both the MM5 (GoM-MM5) and WRF (Gom-WRF) meteorological models for the Gulf of Maine region are presently in operational use to forecast surface weather conditions over the GoM/GB/NES region, providing a 3-day forecast of surface winds, heat flux and precipitation/evaporation for research, fishing and other at-sea activities on the UMASSD SMAST website (http://www.smast.umassd.edu research_projects/GB/mm5/mm5_eta/).  To resolve sub-mesoscale variability in the wind field over NS, we have added a “coastal” domain with a horizontal resolution of 3 km covering the NS/VS/BB region (see red box in Fig. 3). This coastal domain model is driven through a two-way nested approach with the local domain model, with assimilation of in-situ surface wind and other data collected in and around NS.  The high-resolution “coastal” meteo-produced wind and heat flux fields will be used for the proposed NS modeling effort.

Go to GoM-MM5 Forecast System

Posted on January 17, 2014