Triggering rogue waves in opposing currents

TL;DR

This paper demonstrates that opposing currents can naturally trigger rogue waves in stable wave trains, significantly affecting their amplitude and statistical properties, with implications across physics including nonlinear optics.

Contribution

It reveals how opposing currents induce rogue waves and alters statistical properties, providing a new understanding applicable to various physical systems.

Findings

Rogue waves are triggered by opposing currents.

Maximum rogue wave amplitude depends on current-to-group velocity ratio.

Opposing currents significantly change surface elevation statistics.

Abstract

We show that rogue waves can be triggered naturally when a stable wave train enters a region of an opposing current flow. We demonstrate that the maximum amplitude of the rogue wave depends on the ratio between the current velocity, $ U_0 $, and the wave group velocity, $ c_g $. We also reveal that an opposing current can force the development of rogue waves in random wave fields, resulting in a substantial change of the statistical properties of the surface elevation. The present results can be directly adopted in any field of physics in which the focusing Nonlinear Schrodinger equation with non constant coefficient is applicable. In particular, nonlinear optics laboratory experiments are natural candidates for verifying experimentally our results.