WHOI PO

Title: Rossby waves over bathymetry 

Abstract:   Topography plays a central role in ocean dynamics but our intuition is based largely on flat bottom models. This includes aspects like the baroclinic modes used for representing vertical structure and the character of baroclinic instability. A good example is Rossby waves, whose vertical structure and stability are both affected by bathymetry. Relatively modest topography causes the waves to be surface-trapped, which in turn alters their deformation radius and propagation speed. Rossby waves are also baroclinically unstable and this too is altered by bathymetry. If the topographic heights are large enough, energy is transferred directly to topographically-locked flows rather than to the most unstable wave found over a flat bottom. The resulting turbulent flow is also affected by bathymetry, with the deep flow slaved to topography and compensated surface eddies. The resulting flows strongly resemble those in the ocean interior, with westward propagation at the surface and deep topographically-locked gyres.