Lifetimes of rogue wave events in direct numerical simulations of deep-water irregular sea waves (1903.10432v1)

Abstract: The issue of rogue wave lifetimes is addressed in this study, which helps to detail the general picture of this dangerous oceanic phenomenon. The direct numerical simulations of irregular wave ensembles are performed to obtain the complete accurate data on the rogue wave occurrence and evolution. The simulations are conducted by means of the HOS scheme for the potential Euler equations; purely collinear wave systems, moderately crested and short-crested sea states have been simulated. We join instant abnormally high waves in close locations and close time moments to new objects, rogue events, what helps to retrieve the abnormal occurrences more stably and more consistently from the physical point of view. The rogue wave event probability distributions are built based on the simulated wave data. They show the distinctive difference between rough sea states with small directional bandwidth on the one part, and small-amplitude states and short-crested states on the other part. The former support long-living rogue wave patterns (the corresponding probability distributions have heavy tails), though the latter possess exponential probability distributions of rogue event lifetimes and produce much shorter rogue wave events.