The Structure and Dynamics of the Turbulent Hurricane Boundary Layer from Radar Remote Sensing

The planetary boundary layer is a fundamentally turbulent, thin layer of the atmosphere that interacts strongly with the earth’s surface and communicates information on mass, momentum, and energy near the surface to the rest of the troposphere through eddies and fluxes. This layer is of prime importance in hurricanes but is very difficult to measure given the small space and time scales and dangerous conditions. Traditional measurements from dropsondes, flight level data and legacy radar systems has been very valuable, but they cannot provide the true essence of the turbulent hurricane boundary layer (HBL).

Three-dimensional (3D) wind vector retrievals and fluid dynamics calculations using airborne radar data from the Imaging Wind and Rain Airborne Profiler (IWRAP) will be shown to highlight new knowledge of the turbulent HBL. This analysis is conducted at a grid scale of 125 m in the horizontal dimensions and 30 m in the vertical dimension. Supporting data from spaceborne synthetic aperture radar data will also be presented to link with the airborne measurements. The focus of the science is on coherent turbulent structures (CTSs) and their role in the momentum fluxes and kinetic energy budget of the HBL.