Internal Tide Generation by Dual-Ridge Topographies

Tidal flow over submarine features in the deep ocean produces three-dimensional internal waves, shaped by the nature of the seabed geometry and the ocean's stratification, which is defined by the Brunt-Väisälä frequency. Natural oceanic seamounts and ridges are complex, and idealized geometries are often utilized to explore general wavefield dynamics. This work helps bridge the gap between idealized geometries and natural bathymetry by characterizing the wavefield of progressively more complex topography. It builds on previous multi-ridge experimentation by considering additional elements such as slope criticality, asymmetry, and amplitude. In experiments with Gaussian dual-ridge topography, the generated wavefield is not exclusively defined by single-ridge constituents. While relative spacing in sub-critical dual-ridge topography greatly affects kinetic energy generation, slope asymmetry does not and generation is primarily dominated by the steeper ridge. This work draws on a variety of past and present experiments to provide insight into these topographic elements and improve our understanding of the resulting wavefields.