The Boundary Layer Structure of Hurricane Maria (2017) from a Combination of NOAA P3 Aircraft and UAS Coyote Observations

This study investigates the structure of the atmospheric boundary layer of Hurricane Maria (2017) using data collected by both NOAA’s P3 aircraft and UAS Coyotes. On September 22-24, a total of 6 Coyotes were launched by the P3 aircraft into Hurricane Maria, collecting unique in-situ data to sample the boundary layer. In a specially designed boundary-layer inflow module, one Coyote conducted stepped descents from 3 km to 300 m altitude. Dropsondes released from the P3 aircraft that followed the Coyote provide measurements of the overall mean structure the boundary layer, while the Coyote provides measurements of both mean and turbulence structure. Boundary-layer recovery analysis will be conducted to evaluate the role of surface fluxes in the change of the low-level entropy along the inflow trajectory from the outer core to the eyewall. Five UAS Coyotes dropped in the eye of Hurricane Maria that were guided toward the eyewall provide detailed observations of the boundary layer in the eye and eyewall region. The evolution of the kinematic and thermodynamic boundary-layer heights in this region will be studied in the context of air-sea interaction.