European waters on a 25-30km grid

Wind strength and direction; Wave direction; Wind stress and shear; Spectral wave data parameters; Wave height and period statistics

Inapplicable

The UK Meteorological Office Global and European Wave Models are known as 'second generation' wave models because of the way the non-linear interactions in the wave spectrum are parameterised. The significant wave height, mean wave period and direction at each grid point and each time step can be integrated out from a directional spectrum which has 16 direction and 13 frequency components. The model calculations are carried out on a polar stereographic grid, whose exact spacing therefore varies from one latitude to another. The European Wave Model (grid spacing 25-30km) is nested within the Global Model (grid spacing about 150km) from which it takes its boundary wave conditions. The models are run twice daily, driven by wind fields extracted from operational global weather forecasting models. They produce wave forecasts from 12 hours prior to the datum time (T) up to 36 hours ahead, at 3 hourly intervals. As well as noting the time, date, latitude and longitude, each forecast gives the wind speed and direction, and significant wave height, mean wave period and direction for the separate wind-sea and swell components and overall. The data from T-12 hours to T+0 hours is permanently stored in an archive, whilst the data from T+0 hours to T+36 hours is immediately disseminated for forecasting purposes. Sea state observations from fixed buoys, oil platforms, Ocean Weather Ships and, more recently, satellite measurements, are used for real-time 'calibration' of the models, and also for periodic validation exercises. The European Model has been run in its present configuration since October 1986. The archive contains records at 6 hourly intervals from October 1986 to July 1988, and at 3 hourly intervals thereafter. The volume, resolution and consistency of results available in these archived hindcasts provides a good database of wave and over-water information for use in engineering studies. However, the spatial resolution and model physics mean that the data can only be considered representative of deep water conditions at least 20km offshore. HR Wallingford holds a copy of the archive for all grid points within 60km of European coastlines, all grid points in the Irish Sea, English Channel and southern North Sea, and for representative grid points elsewhere further offshore (1732 grid points in all). As an 'Authorised Data User' HR Wallingford is licensed by the Meteorological Office to prepare and supply wind and wave data analyses. Several standard analyses have been developed, e.g. for wave (or wind) climates, wave (or wind) roses, extremes, swell, persistence, and particular storms. Results can be smoothed over an area, and can be presented separately for different years, different seasons and/or different direction sectors.

HR Wallingford Group Ltd.
HR Wallingford Ltd. Howbery Park
Oxon

OX10 8BA
United Kingdom