A Comparison of Convergence- and Surface-Flux-Based Convective Parameterizations with Applications to Tropical Cyclogenesis

The evolutions of radially symmetric vortices and idealized easterly waves are compared using three simple convective parameterization schemes. The parameterizations are formulated for a model atmosphere consisting of three coupled, shallow, constant-density layers. The first was developed by Ooyama and later refined by DeMaria and Pickle (the ODP scheme). Their scheme uses horizontal convergence in the boundary layer to define a vertical mass flux, along with a closure relation based on conservation of moist static energy that determines the vertical redistribution of mass. The second scheme is a modification of the ODP scheme in that convection is allowed to stabilize the profile. A third scheme has the convective mass flux from the boundary layer determined by the assumption that convective up-and downdrafts keep the equivalent potential temperature of the boundary layer in near equilibrium (the BLQ scheme).