Wind-Wave Model with an Optimized Source Function

Abstract: On the basis of the author's earlier results, a new source function for a numerical wind-wave model optimized by the criterion of accuracy and speed of calculation is substantiated. The proposed source function includes (a) an optimized version of the discrete interaction approximation for parametrization of the nonlinear evolution mechanism, (b) a generalized empirical form of the input term modified by adding a special block of the dynamic boundary layer of the atmosphere, and (c) a dissipation term quadratic in the wave spectrum. Particular attention is given to a theoretical substantiation of the least investigated dissipation term. The advantages of the proposed source function are discussed by its comparison to the analogues used in the widespread models of the third generation WAM and WAVEWATCH. At the initial stage of assessing the merits of the proposed model, the results of its testing by the system of academic tests are presented. In the course of testing, some principals of this procedure are formulated. The possibility of using the testing results to study the physics of evolution processes in wind waves is shown. It is noted that the specially added block of the dynamic boundary layer of the atmosphere makes it possible to give an exhaustive description of the air-sea-interface's characteristics, which may be used to improve wave forecasting. This new modeling quality allows us to make a statement about the construction of a model of the next (fourth) generation.