Fig. 3. (a) Representative (top) temperature and (bottom) zonal current data from a thermistor chain mooring and colocated acoustic Doppler current profiler at a depth of 2000 meters in the northern mooring array. (b) Fast conductivity-temperature-depth profiles of density (with large-scale trend removed) showing the vertical motion of constant-density surfaces with time at a depth of 1850 meters in the northern array. Red dots indicate regions of water overturning. UTC = coordinated universal time.