9732678 Montgomery In addition to being of basic fluid dynamical interest, the hurricane is a high impact weather phenomenon that continues to be a priority for basic meteorological research. While considerable insight into the physics of tropical cyclones has been realized using axisymmetric theory and models, fundamental questions remain concerning the role of convective asymmetries in the tropical cyclone lifecycle and in other geophysical vortices as well. Perhaps the most fundamental question is whether convective asymmetries enhance or hinder the vortex. Under this award, the principal investigator will take a two-pronged approach in investigating the nonlinear dynamics of convective asymmetries in the near-core region of hurricanes. The first thrust involves a theoretical investigation of the dynamical impact of outbreaks of cumulus convection on the larger-scale vortex circulation. Determining the role that vortex Rossby wave and gravity-inertia waves play in modulating the mixing of convectively generated potential vorticity near the center of the vortex is the principal objective. The second task involves an observational study using existing radar data to examine the kinematics and dynamics of vortex Rossby waves in hurricanes. This part of the research will be done in collaboration with Dr. Marks of NOAA's Hurricane Research Division.
