Sensitivity of Asymptotic Behavior of Idealized Tropical Cyclone Intensification to Parameterizations of the Atmospheric Boundary Mixing

This presentation highlights major results from a series of idealized experiments with the Advanced Research WRF (ARW) model and the Hurricane WRF (HWRF) model. The purpose of the experiments is to compare the sensitivity of the asymptotic behavior of the intensification of an idealized tropical cyclone to various parameterization schemes of the atmospheric boundary layer (ABL) mixing that are shared by the two models. All the ABL parameterization schemes are driven by the same surface layer scheme so that only the sensitivity of the two models to the ABL mixing above the surface layer is examined in the study. The model is initialized with a weak axisymmetric vortex disturbance in an idealized tropical environment that is favorable for the vortex disturbance to develop into a hurricane. The initial mass and wind fields associated with the weak vortex disturbance are obtained by solving the nonlinear balance equation for the given wind distributions of the initial vortex, and the prescribed background thermal sounding and winds. The comparison focuses on the storm structures and surface wind-pressure relationships. Implications of the results from these experiments in the evaluation of operational hurricane models are also discussed.