One
 annual cycle of upper ocean
 variability
 is illustrated by
 imaging
 the temperature field
 and
 superimposing the vertical
 coordinate
 interfaces and the
 mixed
 layer base (thick line).
 
 The
 annual cycle at point TRDW
 represents
 variability in the
 North
 Atlantic Trade Wind belt
 at
 the southern edge of the 
 subtropical
 gyre. Results are
 generally
 similar, but the KPP
 mixed
 layer tends to be thinner
 than
 in the two K-T mixing
 cases.