Third generation models explicitly represent all the physics relevant for the development of the sea state in two dimensions. They included the “coupled hybrid” and “coupled discrete” formulations. Second generation models, available by the early 1980s, parameterized these interactions. įirst generation wave models did not consider nonlinear wave interactions. The 1970s saw the first operational, hemispheric wave model: the spectral wave ocean model (SWOM) at the Fleet Numerical Oceanography Center. The first numerical model based on the spectral decomposition of the sea state was operated in 1956 by the French Weather Service, and focused on the North Atlantic. This approach allowed to make combined forecasts of wind seas and swells. For forecasting purposes, it was realized that the random nature of the sea state was best described by a spectral decomposition in which the energy of the waves was attributed to as many wave trains as necessary, each with a specific direction and period. ĭuring the 1950s and 1960s, much of the theoretical groundwork necessary for numerical descriptions of wave evolution was laid. Alternatively, the swell part of the state has been forecasted as early as 1920 using remote observations. Early forecasts of the sea state were created manually based upon empirical relationships between the present state of the sea, the expected wind conditions, the fetch/duration, and the direction of the wave propagation.
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