Note on the Rate of Restratification in the Baroclinic Spindown of Fronts.

This paper revisits how the restratifying buoyancy flux w0b0 generated by baroclinic mixed layer instabilities depends on environmental conditions. The frontal spindown is shown to produce buoyancy fluxes that increase significantly beyond the previously proposed and widely used scaling w0b0~fʌ²H² (f is the Coriolis parameter, ʌ is the geostrophic shear, and His the mixed layer depth), irrespective of whether the initial front is broad or narrow. This increase occurs after the initial phase of the nonlinear evolution, when the baroclinic eddies grow in size and develop velocities significantly in excess of the scaling assumption V ~ üH. Implications for parameterizing the restratification caused by baroclinic mixed layer instabilities in coarseresolution models are discussed. [ABSTRACT FROM AUTHOR]