Microcomputer Numerical Ocean Surface Wave Model

Abstract

A numerical wean surface wave model has been developed specifically to operate on desktop super micro-computers. The model uses one or more local and moving grids within which waves of importance at a location of interest are generated. Within these grids, processes of wave energy propagation, dissipation due to opposing winds, and generation by the wind are numerically performed using decoupled propagation numerical wave modeling techniques similar to those in several operational wave models which run on large computers. Swell is propagated accurately from generation areas to the location by great circle techniques. To enhance model use and computer efficiency, the model is general with arbitrary grid spacings, numbers of grid points, computational time steps, and wave energy frequency bands. Tests for three different meteorological situations (a strong frontal system, a major hurricane, and a severe extratropical storm) show that the same model can be used for many types of conditions of interest. The tests also show that the wave growth and dissipation algorithm, which are similar to those in other wave models, could be improved. Specific run times depend on model parameter values (grid spacing, number of grid points, time step, and number of frequency hands). For typical values, a real-time day of wave forecasting or hindcasting can be accomplished in one to ten minutes on available relatively low cost super microcomputers.