Complex/Dynamical Systems Seminar - Bruno Deremble

Vorticity generation in the ocean via the interaction of an eddy and a topographic Kelvin wave.

The interaction of oceanic eddies with topography is still a poorly understood process. In this talk, I will illustrate the complexity of this process with the example of the North Brazil Current rings. These rings propagate northwestward along the coast of Brazil and interact with the topography along their way. In my presentation, I will focus on the propagation mechanism and on the departure from the coast. In an idealized model with sharp topographic features, vorticity can be generated at the boundary, forcing the ring to move away from the
coast. In a realistic configuration (with stratification) the vorticity creation mechanism is even more generic because it does not require sharp topographic features: the eddy will almost always interact with a baroclinic Kelvin and vorticity creation will occur at the boundary.