Extreme wave events in directional, random oceanic sea states

Abstract

We discuss the effect of the directional spreading on the occurrence of extreme wave events. We numerically integrate the envelope equation recently proposed by Trulsen et al. [Phys. Fluids 12, 2432 (2000)] as a weakly nonlinear model for realistic oceanic gravity waves. Initial conditions for numerical simulations are characterized by the spatial JONSWAP power spectrum for several values of the significant wave height, steepness, and directional spreading. We show that by increasing the directionality of the initial spectrum the appearance of extreme events is reduced.