At 2:45 am on July 21,"Haiyan" Ⅰ unmanned aerial vehicle (UAV) passed through typhoon Prapiroon，after taking off from the Boao National UAV Meteorological Observation and testing Base in Hainan, China. At 10 am, Hong Kong Observatory (HKO) started to scan the structure of typhoon Prapiroon with another manned aircraft. This is the first time for China Meteorological Administration (CMA) and HKO to realize the joint observation of multi-aircraft platforms and multi-sensitive areas, and have successfully captured the peripheral cloud structure of Prapiroon.

"Haiyan" Ⅰ unmanned aerial vehicle Photoed by Liu Qian

At 4:45 a.m., "Haiyan" returned with more than 4200 pieces of valid data and sent them to Big Data Cloud Platform "Tianqing", and provided them to National Meteorological Centre (NMC） and other departments.

"Haiyan"accurately dropped eight sounders at a given time and place, monitoring temperature, humidity, wind direction, wind speed, air pressure and other data at different altitudes, observing the three-dimensional structure of Prapiroon. For the first time, it has carried cloud radar, temperature and humidity profilers and other kinds of equipment to obtain information such as cloud echo-reflectivity, temperature, humidity and other information of the passing typhoon, enabling forecasters to understand the structure of typhoon in real time, enabling them to better understand typhoon in a more science-based manner.

At 7:15 a.m., four national upper-air meteorological observing stations in Qingyuan, Heyuan, Shantou and Yangjiang in Guangdong Province, simultaneously carried out BeiDou navigation Drifting Sounding and intensive observations, successfully obtaining contour observations of atmospheric temperature, humidity, wind direction, wind speed and other data in the three phases of "ascending-drifting-descending".

Since June this year, CMA and HKO have worked on this joint operation, and provide more data of the study of typhoon wind field and the energy field.

Editor: XU Nenyu, LIU Qian