Modeling Spectral Dissipation in the Evolution of Wind Waves. Part I: Assessment of Existing Model Performance

Abstract This study examines the performance of a state-of-the-art spectral wind wave model that uses a full solution to the nonlinear interaction source term. The situation investigated here is fetch-limited wind wave evolution, for which a significant observational database exists. The authors consider both the evolutionary characteristics such as the predicted development of wave energy and peak wave frequency with fetch, as well as the predicted local features of the directional wavenumber spectrum: the spectral shape of the dominant wave direction slice, together with the directional spreading function. In view of the customary practice of constraining the shape of the spectral tail region, this investigation required relaxing the constrained tail assumption. This has led to new insight into the dynamic role of the spectral tail region. The calculations have focused on the influence of two of the source terms in the spectral evolution (radiative transfer) equation for the energy density spectrum—thos...