When FY-4 encounters the “King of Typhoon”: You have been seen through by me. Come on!

When you are preparing rain gear and food and ready to lie flat on the weekend, you must have known the route of the “King of Typhoon" – “Lekima”. “Lekima”, the ninth typhoon this year, has presented a fierce and high-profile figure since its appearance on the sea in the east of Philippines at 2 p.m. on August 4, 2019, grabbing the headlines and drawing a lot of attention.

At 3:00 p.m. on August 5, “Lekima” arrived in the sea surface 1300 kilometers away from Fuzhou, Fujian Province. It continued to advance westwards and was highly likely to land China. In response to the challenge of the “King of Typhoon”, FY-4A was fully prepared for continuous and intensive observation of “Lekima” to watch its movements.

At 6 p.m. on August 7, “Lekima” continued to approach the sea surface about 1000 km southeast of Taizhou, Zhejiang Province, and the typhoon intensity increased from Level 10 severe tropical storm to Level 16 super typhoon. At the same, the route shifted towards north, and the most likely landing place changed from Taiwan and Fujian to the land or offshore waters of Jiangsu, Zhejiang and Shanghai.

On August 8, “Lekima” developed into the severest typhoon, with the intensity increasing to Level 17. At 5:00 p.m., it was about 650 kilometers from Wenzhou, Zhejiang Province. At 06:00 on August 9, the center of  “Lekima” was located on the sea surface about 335 kilometers southeast of Wenling City, Zhejiang Province, and was expected to land on the central and northern coast of Zhejiang Province in the night of August 9 or in the early morning of August 10. It may become the severest typhoon to land in China this year.

Each of the hottest headlines is inseparable from a skillful “behind-the-scenes” pusher. The rising exposure of “Lekima” this time was exactly attributed to the continuous monitoring by FY-4A satellite 36,000 kilometers above the earth.

In order to monitor “Lekima”, FY-4A satellite started the intensive observation mode and conducted dynamic monitoring throughout the process, so as to forecast the typhoon route and intensity on a 24-hour basis and provide high-frequency and high-quality observation data for the meteorological department. The advanced geosynchronous radiation imager (AGRI) equipped for the satellite carried out 15-min intensive observation on “Lekima” and provided the cloud map data and temperature and humidity data in and around China; the geosynchronous interferometric infrared sounder (GIIRS) was used to carry out 30-min intensive observation on the typhoon sensitive area obtained by the GRAPES numerical prediction system and provide the vertical profile data of atmospheric temperature and humidity of the typhoon sensitive area; the ground application system can greatly improve the accuracy of typhoon route forecast by conducting data fusion of different observation elements provided by the two high-precision instruments.

Since the launch of the satellite at the end of 2016, FY-4A satellite has become the “mainstay” of China Meteorological Administration when every major meteorological disaster occurred. Since China entered the flood season in March 2019, FY-4A satellite has been on duty 24 hours. With the capability of observing the earth in 15 minutes, observing China in 5 minutes, and observing the area of typhoon or strong convection weather in one minute, FY-4A satellite provides uninterrupted meteorological observation data for China and its surrounding areas, and has made great contribution to preventing and mitigating disasters and ensuring the safety of people’s lives and property in China.

In the face of the annual “King of Typhoon”, FY-4A satellite has mapped out a strategy and got fully prepared. It therefore can encounter “Lekima” with great confidence: You have been seen through by me. Come on!

Sources of partial materials: National Satellite Meteorological Center, Numerical Weather Prediction Center of CMA

Author: Zhang Liguo