Energy cascade in internal wave attractors

TL;DR

This paper investigates how energy cascades in internal wave attractors, revealing a transition from wave turbulence to mixing regimes, with experimental and numerical evidence supporting the energy transfer mechanisms in ocean dynamics.

Contribution

It introduces internal wave attractors as a model for energy cascade, demonstrating triadic interactions and a transition to mixing regimes in large amplitude internal waves.

Findings

Identification of triadic interactions in energy transfer

Evidence of discrete wave turbulence signatures

Transition to high-vorticity mixing regime

Abstract

One of the pivotal questions in the dynamics of the oceans is related to the cascade of mechanical energy in the abyss and its contribution to mixing. Here, we propose internal wave attractors in the large amplitude regime as a unique self-consistent experimental and numerical setup that models a cascade of triadic interactions transferring energy from large-scale monochro-matic input to multi-scale internal wave motion. We also provide signatures of a discrete wave turbulence framework for internal waves. Finally, we show how beyond this regime, we have a clear transition to a regime of small-scale high-vorticity events which induce mixing. Introduction.