The Estimation of Wind-Wave Generation in a Discrete Spectral Model

The estimation of wind-wave generation using a new discrete spectral model is compared to Hasselmann et al.'s (1976) parametric model and to models driven primarily by direct transfer of energy from the atmosphere into the surface waves. The main source term in this new model is a new parameterization of the net energy transfer due to nonlinear wave-wave interactions. After calibration of the wave-wave interaction source term to resemble the form of the solution to the complete Boltzmann integrals, the discrete spectral model is able to reproduce the fetch-limited results of Hasselmann et al. and fits well within the envelope of duration-limited growth curves from recent investigations. Since this model is discretized into frequency and direction components, a finite-difference scheme is used to model propagation effects. The formulation of this model allows simulations in oceanic conditions to consider both wave growth under local winds and swell decay of waves passing through a region simultaneously.