An ECMWF Project for the Prediction of Ocean Waves was established (initially as the optional project) with the agreement of the 34th session of the ECMWF Council. Routine operational production of wave model analysis and forecasts for the global and Mediterranean areas started in July 1992. Initially a global model with a 3 degree grid was run to 10 days, and a Mediterranean model with 0.5 degree grid was run to 5 days. In July 1994. the resolution of the global wave model was increased to 1.5 degrees. In March 1995, two-dimensional wave spectra field was added to the set of fields available from the Project. In June 1998, coupled atmospheric/wave forecasting system was introduced into ECMWF operations. The resolution of the global wave model was increased to 0.5 degrees. In September 2005, the resolution of the global wave model was increased to 0.36 degrees (0.25 degrees in dissemination). In January 2010 the global wave model was increased to 0.25 degrees maintaining the same resolution for dissemination.

The change from the Mediterranean model to the new Mediterranean/Baltic model took place in June 1995 when the area covered was increased. In December 1996, the high resolution shallow water version of the global wave forecast model was introduced into ECMWF operations.

At the end of June 1998, the global wave model was dynamically coupled to the atmospheric model. Winds are passed to the wave model every coupling time step and updated information on the sea surface roughness is passed back to the atmospheric model. The products from the wave global model were the same as before, except that the GRIB format of the 2-D spectra had changed. They were archived as global fields, one per frequency and direction. The corresponding GRIB parameter was therefore changed to differentiate this new format from the old one. The analysed global spectral fields were also made available every 6 hours. 12 directions and 25 frequencies were used. Following the coupling of the deterministic forecast model with the wave model, the ensemble forecasting system was also upgraded to run with the coupled wave model. In that configuration, the wave model grid resolution was 0.5 by 0.5 degree and only the deep water physics option was used. Wave probabilistic forecasts were therefore possible. In September 2005, horizontal resolution was increased to 0.25 degrees

The Mediterranean model was modified at the end of October 1998 to cover an area that extends from the Gulf of Mexico to the Black Sea 810 North/980 West/90 North/420 East and has a resolution of 0.25 by 0.25 degrees. The spatial grid was changed to a quasi-regular grid with an horizontal grid spacing of the order of 28 km. The spectral resolution and the forecast length were kept the same as previously. Note that this new model is still referred to as the Mediterranean model when requesting the GRIB data.

In the autumn of 2000, the global wave model spectral resolution was increased to 24 directions and 30 frequencies. The frequency range is such that 2 new frequency bins are added to the low frequency part of the spectrum and 3 new bins to the high frequency limit. In March 2009 the domain of the wave model was extended from 81 degrees North to 90 degrees North.

In January 2010, the wave model spectral resolution was increased to 36 directions and 36 frequencies. The Mediterranean wave model resolution increased to 0.125 by 0.125 degrees.

07-11-2011