Convection-free zones in intense tropical cyclones

Within the framework of nondivergent barotropic dynamics, hypothetical profiles of vorticity in tropical cyclones were examined to obtain characteristic filamentation time scales. Filamentation times were compared with the tangential winds corresponding to axisymmetric Gaussian vortex vorticity profiles. It was determined that the most intense vortices contain the largest rapid filamentation zones. Numerical integrations show the evolution of the filamentation timescales for different scenarios. Simulations verify that rapid filamentation in as little as 5 minutes acts to form vorticity moats in the strongest vortices. Furthermore, numerical experiments reveal rapid filamentation zones are present in concentric ring and mesovortex situations.