Toward Obtaining Daily Vertical Profiles of In Situ Meteorological Measurements from Small Unmanned Aircraft Systems

Earth’s atmospheric boundary layer (ABL) has traditionally been difficult to sample, yet adequate characterizations of it are essential to weather forecasting. Surface-based observational platforms, e.g., weather stations and flux towers, only penetrate at most a few tens of meters into the ABL. Rawinsondes provide a snapshot of the ABL and are released only twice daily from locations that are unevenly distributed across the world. Like rawinsondes, surface based lidars and sodars provide profiles at only one point in space, but require a significant investment of resources, both in terms of monetary cost and manpower. Although radars provide better spatial coverage than rawinsondes, lidars, and sodars, oftentimes radars overshoot the ABL and thereby do not sample it well. Therefore, in recent years, small unmanned aircraft systems (sUAS) have begun being used to sample the ABL to close this significant observation gap.

In this work, we highlight results obtained using vertical profiles from a DJI S-1000 and MD4-1000, which are two types of vertical takeoff and landing (VTOL) sUAS. We share examples from the Verification of the Origins of Rotation in Tornadoes Experiment in the Southeast U.S. (VORTEX-SE), conducted in Alabama in spring 2016 and 2017, as well as the Land Atmosphere Feedback Experiment (LAFE), conducted in northern Oklahoma in August 2017. During VORTEX-SE and LAFE, we performed 96 vertical sUAS profiles to sample the evolution of near surface (up to 365 m above ground level) temperature and moisture fields. We also present recent results from a field study conducted in eastern Tennessee in which multiple daily vertical sUAS profiles are obtained from a VTOL sUAS. We discuss how performing these frequent vertical profiles are an important step toward using sUAS observations in operational weather forecasting to improve short-term weather prediction.