Buoyancy can not be observed directly, nor is it defined uniquely. It can be deduced from simultaneous measurements of kinematic and thermodynamic fields, but high-resolution measurements of these fields in a tropical cyclone only exist along an aircraft track or a dropsonde profile. An indirect retrieval approach will be presented, which allows estimation of the three-dimensional buoyancy and pressure perturbations in the entire eyewall region using aircraft radar observations.
A detailed analysis of the structure and buoyancy of the eyewall convection in Hurricane Rita (2005) will be presented. First, the performance of the thermodynamic retrieval approach will be assessed using a Weather Research and Forecasting (WRF) simulation. Second, the retrieval will be applied to airborne observations from the Hurricane Rainband and Intensity Change Experiment (RAINEX) field campaign. The results will be used to analyze the convective forcing in the eyewall during periods of intensification and enhanced vertical wind shear.