Thermodynamic structure of tropical cyclones during genesis

The US Air Force Reserve makes frequent flights into tropical cyclones during the early stages of development. Typically, such flights are made at altitudes less than 500m (within the boundary layer). The current study uses observations collected on-board these aircraft, and those measured by dropsondes, to investigate the low-level thermodynamic structure of developing tropical cyclones. Particular attention is paid to the radial variations of θ_e in the BL, as revealed by the in situ observations.

 Of primary interest are the very early stages of organization before and just after tropical depression strength has been reached.  There appear to be distinct differences in the nature of development between low vertical shear and high vertical shear environments.  We will show the mesoscale evolution of θ_e, convection, winds, and temperature in both circumstances. The goal is to identify the critical processes that produce development at these very early stages of tropical cyclones.