| Summary: | The behavior of different parameterizations of mixed layer physics
when used in an oceanic general circulation model (OGCM) having coarse
resolution of the upper ocean is examined. The method of parameterization
is expected to have an important effect on the resulting sea surface
temperature, and hence affect the model's overall fidelity from the viewpoint
of air-sea interaction. Tests of three possible parameterizations
differ in the manner in which the mixed layer depth is determined: predetermination,
diagnostic determination, or prognostic determination.
The sea surface temperature is taken to be equivalent to the top OGCM
layer temperature in the first two methods, while it is found prognostically
in the third method. Results show that for typical forcing cases
such as strong insolation, weak surface cooling or weak winds, mixing is
insufficient to cause heat transfer between the top two OGCM layers,
which occupy the uppermost 500 m of the model. The predetermined and
diagnostically determined mixed layer depth parameterizations reduce to
a diffusive mixing parameterization, while the prognostic approach satisfactorily
models mixed layer depths for all forcing cases. The prognostic
method also agrees most closely with the results of a mixed layer
model and with observations. === Graduation date: 1978
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