Idealized tropical cyclones in atmospheric general circulation models: sensitivity to initial conditions and physics parameterizations

The paper discusses the design of idealized tropical cyclone experiments in Atmospheric General Circulation Models. The development of an idealized, initially weak warm-core vortex is investigated with varying initial conditions that include variations of the maximum wind speed and radius of maximum wind.

The most energetic initial configuration is an ideal candidate to study the impact of physical parameterizations on the evolution of the tropical cyclone. A group of sensitivity tests is presented using high-resolution versions of the Community Atmosphere Model CAM 3.1 developed at the National Center for Atmospheric Research (NCAR). In particular, two different physics suites are assessed on an ocean-covered Earth with prescribed sea surface temperatures. These are the full CAM 3.1 physics parameterization package and a simplified physics suite that only incorporates surface fluxes, turbulence, and large-scale precipitation as the driving mechanisms. It is found that a simplified physics suite produces comparable results to the full-physics simulations, thereby allowing an in-depth investigation of the interplay between the tropical cyclone and the physical parameterizations.