On-Demand Wind Profiling with Multirotor UAS to Monitor the Atmospheric Transport of Harmful Algal Blooms

Abstract:

New real-time detection methods are needed to track, predict, and mitigate the atmospheric transport of hazardous agents. Harmful algal blooms (HABs), caused mostly by toxic cyanobacteria, may be aerosolized from large bodies of water and threaten communities downwind. Accurate measurements of wind speed and direction are necessary to drive local atmospheric transport models that predict the risk of exposure. Conventional wind profiling technology is cost-prohibitive and mostly limited to operations over land. Here, we present on-demand wind profiling using a multirotor unmanned aerial system (UAS) to quantify lower-atmosphere wind variations induced by land and water surface heterogeneity, as well as surface and atmosphere thermal effects. Thirty-two multirotor UAS flights were conducted over land and water during a HAB at Grand Lake St. Marys, Ohio in August, 2019. Additional flights were conducted next to a sonic anemometer and a SoDAR wind profiler in Blacksburg, Virginia to validate multirotor UAS wind velocity observations derived from hovering and ascending flight regimes. We demonstrate a significant difference in the wind profile over-water compared to over-land near a lake shoreline, even for measurements separated horizontally by less than 100 m. Results from these field experiments will be used to understand how atmospheric wind conditions can influence the transport and dispersion of HABs from bodies of water to surrounding communities.