Simple Models of Stratification

Abstract

Abstract Simple analytical and numerical models of gratified circulation are discussed. The models are driven by buoyancy and mechanical forcing, and buoyancy diffusion is parameterized in term of diapycnal mass fluxes. The interior responds in typical Sverdrup fashion, and the requirements of balanced heat and energy budgets are invoked to calculate the eastern boundary stratification parameters. This effort differs from past attempts to calculate stratification in that buoyancy flux boundary conditions or explicitly considered in the calculation of diapycnal fluxes. A major feature of the solutions is the interplay of planetary dynamics and buoyancy diffusion. This results in the most important components of the thermocline structure, namely density outcrops and interior “pinchoffs.” These are, in turn, essential to the production of thermodynamically balanced states. Some aspects of the present model resemble features found in previous numerical models.