Ocean Internal Waves

Near-inertial waves (NIW’s) and ocean internal tides are considered to be the main sources for the diapycnal mixing necessary to maintain the Meridional Overturning Circulation. NIW’s are produced in the mixing layer of the oceans mainly by the large scale winds. After their generation, part of them is transmitted from the surface mixed layer downward by means of two processes. The first one is the β-dispersion effect that produce both downward and equatorward propagation. The second process is the horizontal variation of the relative vorticity that influences the propagation of NIW’s allowing the trapping inside anticyclonic eddies.

A variety of observations have been made that illustrate regions of high near-inertial energy in the thermocline associated with anticyclonic vorticity. However, much of these observations have been obtained in intense warm core rings or after the pass of storms. A global picture, that is, how much of the near inertial energy input at the sea surface is actually transmitted by oceanic eddies for mixing to the ocean interior in ordinary meteorological conditions, is still lacking. The aim of this research is to study the trapping of NIW’s waves and the generation of deep mixing in oceanic anticyclonic eddies of the Canary Eddy Corridor.