Marginally Unstable Turbulence in Forced, Stratified Shear Flows

The upper equatorial oceans provide a natural laboratory for the study of turbulence in stratified, parallel shear flows. The combination of steady trade winds and vanishing Coriolis acceleration leads to persistent, sheared currents, and thereby supports a turbulence regime that is roughly in equilibrium with the forcing - the so-called "deep cycle" of equatorial turbulence. The downward heat flux carried by this turbulence is a critical element of the equatorial climate system and is notoriously difficult to represent in models. In this talk I’ll describe our current understanding of the deep cycle and its implications for stratified shear flows in general (e.g. gravity currents, capping layers, estuarine flows).