Resonant Triad Instability in Stratified Fluids

TL;DR

This paper presents the first experimental measurement of the growth rate of resonant triad instability in stratified fluids, comparing results with theoretical predictions to enhance understanding of energy transfer in geophysical and astrophysical flows.

Contribution

It provides the first experimental quantification of the growth rate of resonant triad instability in stratified fluids, validating theoretical models.

Findings

Measured growth rates match theoretical predictions.

Resonant triad instability facilitates energy transfer to smaller scales.

Experimental data supports the role of internal waves in fluid mixing.

Abstract

Internal gravity waves contribute to fluid mixing and energy transport, not only in oceans but also in the atmosphere and in astrophysical bodies. We provide here the first experimental measurement of the growth rate of a resonant triad instability (also called parametric subharmonic instability) transferring energy to smaller scales where it is dissipated. We make careful and quantitative comparisons with theoretical predictions for propagating vertical modes in laboratory experiments.