In this and the seven subsequent slides, five annual cycles of upper ocean variability are illustrated by imaging the temperature field and superimposing the vertical coordinate interfaces and the mixed layer base (thick line). At the SARG grid point, variability in and above the seasonal thermocline within the interior western subtropical gyre does not display long-term climate drift. Except for the KPP case, subtropical mode water thins (deeper water shifts upward) near the end of the time interval.