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    One
    annual cycle of upper ocean 
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    variability
    is illustrated by 
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    imaging
    the temperature field 
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    and
    superimposing the vertical 
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    coordinate
    interfaces and the 
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    mixed
    layer base (thick line). 
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    The
    annual cycle at point SARG 
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    represents
    variability in the 
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    interior
    western subtropical gyre. 
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    All
    three simulated fields are 
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    very similar. 
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