Tracking breather dynamics in irregular sea state conditions

TL;DR

This study demonstrates that extreme wave events in irregular ocean conditions can be traced back to exact breather solutions of the nonlinear Schrödinger equation, confirmed through experiments and simulations.

Contribution

It provides experimental and numerical evidence linking rogue waves in chaotic sea states to NLSE breather solutions, highlighting their predictive significance.

Findings

Experimental confirmation of NLSE breather origins of rogue waves

Good agreement between laboratory experiments and simulations

Universal weakly nonlinear equations are key to understanding extreme events

Abstract

Breather solutions of the nonlinear Schr\"odinger equation (NLSE) are known to be considered as backbone models for extreme events in the ocean as well as in Kerr media. These exact determinisitic rogue wave (RW) prototypes on a regular background describe a wide-range of modulation instability configurations. Alternatively, oceanic or electromagnetic wave fields can be of chaotic nature and it is known that RWs may develop in such conditions as well. We report an experimental study confirming that extreme localizations in an irregular oceanic JONSWAP wave field can be tracked back to originate from exact NLSE breather solutions, such as the Peregrine breather. Numerical NLSE as well as modified NLSE simulations are both in good agreement with laboratory experiments and highlight the significance of universal weakly nonlinear evolution equations in the emergence as well as prediction of extreme events in nonlinear dispersive media.