2021年18号台风“圆规”的特征分析
Analysis on the Characteristics of Typhoon No. 18 in 2021

利用日本气象厅所提供的台风最佳路径及强度数据、欧洲气象资料中心的第五代再分析资料，对2021年18号台风“圆规”的路径与强度以及其在菲律宾和中国海南岛登陆的两次过程中的降水、环流形势等特征进行了分析。结果表明：1) 台风“圆规”于10月8日13时在菲律宾以东洋面生成后先向东北移动，后因西太平洋副热带高压的南下减弱，台风转向一路西行，先后于11日09时登陆菲律宾，13日09时登陆海南岛；2) 台风发展移动过程中，中心最大风速与最低气压呈反位相结构；在两次登录过程中，登陆前的降水范围逐渐扩大，降水强度随着登陆达到最大值，随后在登陆后逐步减小；3) 西太副高对台风“圆规”的移动路径有着重要的调制作用，稳定维持的中高纬槽脊结构输送的冷空气与低纬度赤道附近西北暖湿气流的交汇，为台风强度的发展及台风降水提供了稳定的三维结构和水汽条件。
Using the best path and intensity data of the typhoon provided by the Japan Meteorological Agency and the fifth generation reanalysis data of the European Meteorological Data Center, the path and intensity of typhoon 18 in 2021, as well as the precipitation and circulation situation during the two landings in the Philippines and Hainan Island, China, were analyzed. The results show that: 1) Typhoon “compass” moved northeast to the east ocean at 13 o’clock on October 8. Later, due to the southward weakening of the Western Pacific subtropical high, the typhoon turned all the west, landing in the Philippines at 09:00 on the 11th, landing on Hainan Island at 09:00 on November 13th; 2) During the development and movement of the typhoon, the central maximum wind speed and the minimum air pressure show the reverse phase structure; During the two login sessions, the range of precipitation before landfall was gradually expanded. The precipitation intensity reaches its maximum with landfall. Then they gradually decrease after landing; 3) The west Pacific subtropical high has an important role in modulating the moving path of the typhoon “compass”. The intersection of the cold air transported by the stably maintained mid-and high-latitude trough ridge structure and the warm and humid air flow in the northwest near the low-latitude equator, it provides a stable three-dimensional structure and water vapor conditions for the development of typhoon strength and typhoon precipitation.