Scattering and Trapping of Obliquely Incident, Low-Mode Internal Tides off a Continental Shelf and Slope

We demonstrate – using linear scattering theory and an idealized, stratified, rotating ocean domain, with a flat bottom deep ocean and a straight continental slope and shelf – that a high-mode (mode 3) Poincare wave incident on the coastal margin can excite large amplitude leaky coastal trapped waves (CTWs) or leaky edge waves along the coastal margin dependent on the frequency and alongshore wavenumber of the incident wave. The large response only occurs when low modes (modes one or two) are evanescent in the deep ocean. This may be a means by which large amplitude, alongshore propagating internal tides can be excited at the coastal margin. The fact that the leaky CTW and edge wave response is sensitive to alongshore wavenumber suggests that their excitation in real oceans will be temporally and spatial intermittent due to variations in incidence angles of deep ocean internal tides and spatial and temporal variations in stratification.