Internal wave dissipation and scattering by low-amplitude rough topography

The propagation of internal waves plays an important role in the propagation of energy and momentum throughout the ocean. Generated from underlying topographic features or by storms, these waves can take the form of low-mode waves propagating large distances and high-mode internal wave beams. Topographic generation has been studied focusing on finite-size features that produce wave beams that eventually breakdown to the low mode waves that propagate large distances. For both low-mode and wave beams, reflection studies have typically focused on smooth topography and low amplitude waves, which provide a strong theoretical framework for understanding reflection and propagation. However, fine scale roughness of the underlying topography impacts the generation of backscatter and harmonics. Using numerical simulations, we investigate the impact of both periodic and random fine-scale topographic roughness on the reflection and propagation of internal waves over an otherwise flat topography.