Séminaire
Turbulence in western boundary currents like the Gulf Stream plays a potentially important role in the global tracer circulation, water mass formation and the energetics of the oceanic general circulation. In this presentation, I will discuss observations of velocity, density and microstructure in the upper thermocline of the winter Gulf Stream obtained during the 2012 LatMix experiment. The observations, which were made in a nearly Lagrangian frame of reference, reveal ubiquitous banded coherent shear structures characteristic of near-inertial waves. Upward propagating lines of constant wave shear are nearly parallel to slanted isopycnals. The shear vector tends to rotate clockwise with both depth and time. And the shear structures are associated with banded patterns of low Richardson number (Ri less than 1) and elevated dissipation rate, O(10-8 - 10-7) W/kg.