Extreme dynamics of wave groups on jet currents

Physics of Fluids. 2023. Vol. 35. No. 12. Article 126606.

A. V. Slunyaev, Shrira V. I.

Rogue waves are known to be much more common on jet currents. A possible explanation was put forward in Shrira and Slunyaev
[“Nonlinear dynamics of trapped waves on jet currents and rogue waves,” Phys. Rev. E 89, 041002(R) (2014)] for the waves trapped on
current robust long-lived envelope solitary waves localized in both horizontal directions become possible, such wave patterns cannot exist in
the absence of the current. In this work, we investigate interactions between envelope solitons of essentially nonlinear trapped waves by
means of the direct numerical simulation of the Euler equations. The solitary waves remain localized in both horizontal directions for hundreds
of wave periods. We also demonstrate a high efficiency of the developed analytic nonlinear mode theory for description of the longlived
solitary patterns up to remarkably steep waves. We show robustness of the solitons in the course of interactions and the possibility of
extreme wave generation as a result of solitons’ collisions. Their collisions are shown to be nearly elastic. These robust solitary waves obtained
from the Euler equations without weak nonlinearity assumptions are viewed as a plausible model of rogue waves on jet currents.

Keywords: численное моделирование, hydrodynamics, уравнения гидродинамики, numerical simulation, envelope solitons, солитоны огибающей