Mixing in the western equatorial Pacific and its modulation by ENSO

High vertical resolution measurements of the flow in the western equatorial Pacific reveal the vertical shear to be dominated by flow features that have a small vertical scale (O(10 m)). This is true for all the measurements we have taken over a 3 year period and differing ENSO states. Much of the measured turbulent activity is found to be associated with these small scale features, with the suggestion that mixing in the region is heavily influenced by the presence of this small scale activity. The level of mixing within and above the thermocline is strongly modulated by ENSO events, with the level of mixing being significantly greater during the observed La Nina event. Changes to the stratification above the thermocline during ENSO events play a major role in both changes to the level of turbulent activity and the effective vertical diffusion coefficient. Citation: Richards, K. J., Y. Kashino, A. Natarov, and E. Firing (2012), Mixing in the western equatorial Pacific and its modulation by ENSO, Geophys. Res. Lett., 39, L02604, doi: 10.1029/2011GL050439.