Observations of the spectra of hurricane generated waves

An extensive database of one-dimensional spectra observed during the passage of hurricanes is examined. Spectra recorded within eight times the radius to maximum winds of the centers of hurricanes are unimodal and remarkably similar to previously recorded fetch limited spectra. Parametric spectral forms such as JONSWAP and that of Donelan et al. approximate the data well. In addition, the functional dependence of the spectral parameters alpha and gamma on the inverse wave age is consistent with that observed under fetch limited conditions. It is concluded that the similarity of the hurricane wave spectra to those observed for simpler fetch limited spectra is largely due to the effects of nonlinear interactions. The shape stabilizing effects of the nonlinear interactions reshape spectra consisting of a mix of swell and wind-sea to conform with typical one-dimensional fetch limited wind-sea forms. (C) 1997 Elsevier Science Ltd.