Michelson,Sara, National Oceanic and Atmospheric
Administration/ESRL and CIRES/University of Colorado and Jian-Wen Bao,
NOAA/ESRL
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.