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

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.