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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 STMW 
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    represents
    variability in the 
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    subtropical
    mode water formation 
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    region
    at the northern edge of 
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    the subtropical
    gyre. As 
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    illustrated
    earlier, the mode water 
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    temperature
    is most accurate in 
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    the KPP
    simulation, but 
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    substantially
    too cold in the 
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    MICOM
    mode simulation. 
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