Title : Ekman-inertial instability in the ocean
Contact : Chantal Staquet
Abstract : Due to their inherently limited extent, oceanic density fronts exhibit strong velocity shears. These shears lead to instabilities that play a significant role in energy dissipation. Most theoretical descriptions of these instabilities rely on linear stability analysis of volume perturbations. In this presentation, I will describe a novel instability that defies this analysis. It starts from changes in wind conditions at the surface rather than perturbations in the volume, and propagates down, layer by layer, via viscous stresses. It initially grows much faster than any known frontal instability, potentially locally overwhelming them, with several implications on our understanding of frontal dynamics.