Soliton spectra of random water waves in shallow basins

TL;DR

This paper introduces a novel method for analyzing shallow water random wave fields using inverse scattering to identify soliton components, providing a simpler alternative to Fourier and nonlinear mode analyses.

Contribution

It presents an alternative, simpler analysis of random water waves in shallow basins using solitons and inverse scattering, improving understanding of wave dynamics.

Findings

Successfully identified soliton components in simulated wave data.

Applied the method to real laboratory wind wave data.

Constructed soliton amplitude distribution functions.

Abstract

Interpretation of random wave field on a shallow water in terms of Fourier spectra is not adequate, when wave amplitudes are not infinitesimally small. A nonlinearity of wave fields leads to the harmonic interactions and random variation of Fourier spectra. As has been shown by Osborne and his co-authors, a more adequate analysis can be performed in terms of nonlinear modes representing cnoidal waves; a spectrum of such modes remains unchanged even in the process of nonlinear mode interactions. Here we show that there is an alternative and more simple analysis of random wave fields on shallow water, which can be presented in terms of interacting Korteweg - de Vries solitons. The data processing of random wave field is developed on the basis of inverse scattering method. The soliton component obscured in a random wave field is determined and a corresponding distribution function of number of solitons on their amplitudes is constructed. The approach developed is illustrated by means of artificially generated quasi-random wave field and applied to the real data interpretation of wind waves generated in the laboratory wind tank.