Inner-core Vacillation Cycles during the Intensification of Hurricane Katrina

摘要

A simulation of Hurricane Katrina (2005) using the Australian Bureau of Meteorology s operational model for tropical-cyclone prediction (TCLAPS) shows that the simulated vortex vacillates between almost symmetric and highly asymmetric phases. The picture to emerge from the model results is that vacillation cycles tend to occur during the intensification stage, before the vortex has developed into an adverse environment for both vortical convection and the growth of barotropic instability in the eyewall region. In other words, these vacillation cycles appear to be part of the intensification process in relatively young tropical cyclones. Eye replacement cycles (ERCs) tend to occur in strong and mature hurricanes.