Stirring and mixing: What are the rate-controlling processes?
نویسنده
چکیده
The parameterization of unresolved processes in oceanographic models is complicated by the interplay of processes on a wide variety of space and time scales. The lack of spectral gaps further complicates the situation, though perhaps not as seriously as might be feared. Understanding the interaction of different processes, and determining which one is critical, or rate-controlling, may be aided by thinking in terms of a triple decomposition into mean, eddies and turbulence. Particular physical processes reviewed include the fate of energy released in baroclinic instability and the ultimate thermohaline frontolytic mechanism on mean isopycnal surfaces. Both of these issues may have implications for diapycnal mixing rates. Another important question reviewed briefly is that of the efficiency of conversion of turbulent kinetic energy to mean potential energy; we do not know what “external” parameters determine it. The kinematic details of overturning are also discussed in terms of the probability distribution of displacements from a stably stratified buoyancy profile.
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