Coyote unmanned aircraft system observations in Hurricane Edouard (2014) Earth Space Science

Horizontal wind, temperature, and moisture observations are presented from two Coyote unmanned aircraft system (UAS) flights in the boundary layer of Hurricane Edouard (2014). The first flight sampled the meteorological conditions in the eye and eyewall at altitudes from 900 to 1500 m while Edouard was a major hurricane (105 kt) on 16 September 2014. The following day, a second Coyote sampled the inflow layer outside of the storm core at ~760 m altitude, when Edouard had weakened to an 80‐kt hurricane. These flights represent the first deployments of a UAS from an airborne manned aircraft into a tropical cyclone. Comparisons between the Coyote data and the Lockheed WP‐3D Orion (WP‐3D) flight‐level measurements and analyses constructed from dropsonde data are also provided. On 16 September 2014, the Coyote‐measured horizontal wind speeds agree, on average, to within ~1 m s−1 of the wind speeds observed by the WP‐3D and reproduce the shape of the radial wind profile from the WP‐3D measurements. For the inflow layer experiment on 17 September, the mean wind speeds from the Coyote and the dropsonde analysis differ by only 0.5 m s−1, while the Coyote captured increased variability (σ  = 3.4 m s−1) in the horizontal wind field compared to the dropsonde analysis (σ  = 2.2 m s−1). Thermodynamic data from the Coyote and dropsondes agree well for both flights, with average discrepancies of 0.4°C and 0.0°C for temperature and 0.7°C and 1.3°C for dew point temperature on 16 and 17 September, respectively. 2016 OMAO (Office of Marine and Aviation Operations) OAR (Oceanic and Atmospheric Research) AOML (Atlantic Oceanographic and Meteorological Laboratory) ESRL (Earth System Research Laboratory) PSL (Physical Sciences Laboratory) Submitted https://doi.org/10.1002/2016EA000187 CC BY-NC-ND 1953