Comprehensive Marine Observing Experiment Based on High-Altitude Large Unmanned Aerial Vehicle (South China Sea Experiment 2020 of the “Petrel Project”)

In collaboration with 12 other institutions, the Meteorological Observation Center of the China Meteorological Administration undertook a comprehensive marine observation experiment in the South China Sea using the Yilong-10 high-altitude large unmanned aerial vehicle (UAV). The Yilong-10 UAV carried a self-developed dropped sounding system and a millimeter-wave cloud radar system. In addition, a solar-powered unmanned surface vessel and two drifting buoys were also used, and an intelligent reciprocating horizontal drifting radiosonde system was deployed from the Sansha Meteorological Observing Station to produce a comprehensive three-dimensional atmospheric profile over the South China Sea. The first comprehensive three-dimensional observations, obtained from July 31 to August 2, 2020, were used to investigate the formation and development processes of Typhoon Senlake. The observational data comprised measurements of 21 oceanic and meteorological elements acquired by the 5 devices, together with video footage from the UAV. The data played an important role in determining the location and intensity of Typhoon Senlake. The experiment marked a milestone not only in terms of analysis of the structure and impact of a typhoon in the South China Sea, but also in relation to the application of numerical models and the future establishment of an operational UAV meteorological observing system. The experiment demonstrated the feasibility of using a high-altitude large UAV to fill the gap in comprehensive meteorological observations of marine areas and typhoons near China.