The Role of Clear Air Turbulence in the Production of Potential vorticity in the Vicinity of Upper Tropospheric jet Stream-Frontal Systems

Abstract

The nonconservation of potential vorticity in the vicinity of upper tropospheric frontal systems is examined by identifying the mechanisms by which turbulence can change potential vorticity. Based on observed beat and momentum fluxes, a turbulence parameterization is included in a two-dimensional, isentropic primitive equation model. The relative importance of the turbulent heat and momentum fluxes in generating potential vorticity is examined by considering turbulence characterized by Prandtl numbers 1 and 2.5. Potential vorticity production and destruction rates > 50% day?1 were produced by the turbulent heat and momentum fluxes.