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).
 Differences
 in upper-ocean
 temperature
 can be large at grid
 points
 located in frontal zones and
 the
 boundary regions between
 gyres.
 Horizontal displacement
 of
 these oceanographic features
 among
 simulations can lead to
 substantial
 T differences. In
 general,
 smaller differences are
 observed
 at grid points located
 at
 gyre interiors.
 
 At
 the NAC grid point, low-
 frequency/secular
 variability in the
 subtropical/subpolar
 gyre boundary
 is
 evident.