THE WIND-DRIVEN OCEAN CIRCULATION WITH AN ISOPYCNIC-THICKNESS MIXING PARAMETERIZATION

Numerical solutions are examined for the nearly adiabatic, large-scale ocean circulation in a midlatitude, rectangular domain with steady wi nd driving. The model used is the balance equations and its various su bsets; hence, dynamical effects at finite Rossby number are included. The solutions are steady ones, and the necessary transports by the mis sing mesoscale eddies are parameterized, in part, using the authors' p revious proposal for isopycnally oriented mixing of tracers and isopyc nal thickness or static stability. This yields qualitatively credible, quasi-adiabatic solutions for realistic magnitudes for the subgrid-sc ale transport coefficients. Among these solutions are ones with nearly homogeneous fields of potential vorticity on upper-thermocline isopyc nal surfaces, even though the parameterized eddy mixing does not act d irectly to this end.