A laboratory study of low-mode internal tide scattering by finite-amplitude topography

TL;DR

This laboratory study investigates how a low-mode internal tide interacts with finite-amplitude Gaussian topography, revealing significant reflection and energy transfer to higher modes, which enhances understanding of internal wave scattering.

Contribution

First experimental evidence showing how supercritical topography scatters low-mode internal tides and transfers energy to higher modes.

Findings

Supercritical Gaussian topography causes significant internal tide reflection.

Energy transfer from low to high modes is observed.

Laboratory results support theoretical predictions.

Abstract

We present the first laboratory experimental results concerning the scattering of a low-mode internal tide by a gaussian topography. Experiments performed at the Coriolis Platform in Grenoble used a recently-conceived internal wave generator as a means of producing a high-quality mode-1 wave field. The evolution of the wave field in the absence and presence of a supercritical Gaussian was studied by performing spatiotemporal modal decompositions of velocity field data obtained using Particle Image Velocimetry (PIV). The results support predictions that large-amplitude supercritical topography produces significant reflection of the internal tide and transfer of energy from low to high modes.