Airborne Radar Observations of Heavy Precipitation Systems

A review of airborne radar observations in tropical cyclones (TCs) is presented. The progress in radar hardware, sampling strategy and Doppler radar analysis techniques to deduce TC kinematic structures is discussed. The drastically improved temporal and spatial resolution of airborne radar data reveals individual storm structures unable to be observed previously. The kinematic structures and dynamic processes of TCs are primarily studied by decomposing the Doppler radar derived TC circulations into an area-averaged mean wind, and axisymmetric and asymmetric structures in cylindrical coordinates. These detailed TC structures allow the examination of barotropic instability, vortex Rossby waves, and vortex dynamics from real data. The observations in RAINEX have advanced the understanding of concentric eyewalls, rainband structures, and asymmetric precipitation structures under the influence of vertical wind shear. In the near future, the primary research focus is on TC genesis with field experiments, such as T-PARC and PREDICT, using airborne radars to sample the key convective processes governing the TC genesis processes.