Large-Scale Deterministic Predictions of Nonlinear Ocean Wave-Fields

A direct phase-resolved simulation tool for nonlinear ocean surface wave-field evolution, which is named SNOW (simulation of nonlinear ocean wave-fields), is applied to under the dynamics and to obtain a reliable prediction of realistic ocean waves. Unlike the phase-averaged approach, SNOW solves the primitive Euler equation, preserves the phases of the wave-field during its nonlinear evolution, and accounts for the effects of the complex physical processes (such as wave breaking and wind input) in a direct physics-based way. Therefore, the detailed descriptions of the free surface and the kinematics/dynamics of the wave-field are obtained with SNOW. In this work, we focus on the understanding of the characteristics and occurrence statistics of rogue wave events and the development and validation of a novel capability for deterministic prediction of such wave events in realistic ocean environments. Specifically, our study shows that the inclusion of nonlinear wave-wave interactions is critical for the prediction of rogue wave occurrence especially in sea states with relatively narrow wave spectrum bandwidth and narrow directional spreading angle. Moreover, it is found that nonlinear coupling between swell and wind waves in crossing sea states can significantly increase the occurrence of rogue wave events. In addition, we demonstrate and validate the capability of phased-resolved reconstruction and forecasting of realistic ocean wave-field evolution by the use of hybrid radar/wave-probe sensed wave data with SNOW simulations.