Climatic Characteristics of Influencing China Binary Tropical Cyclones |
| |
| Authors: | Yanjun Xie Fumin Ren Guoping Li Mingyang Wang Hui Yang |
| |
| Institution: | 1.School of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu 610225, China;2.State Key Laboratory of Severe Weather/Chinese Academy of Meteorological Sciences，Beijing 100081，China;3.Zhuzhou Meteorological Office，Hu'nan Zhuzhou 412003, China |
| |
| Abstract: | Based on the definition of Binary Tropical Cyclones (BTCs), the definition of influencing china binary tropical cyclones (ICBTCs) was proposed. During the BTCs period, if at least one of the two tropical cyclones causes precipitation over the mainland or one of the two largest islands-Hainan and Taiwan of China, the BTC is called ICBTC. Then, based on daily precipitation data and the tropical cyclone best track data during 1960-2017, this study analyzed the climatic characteristics of ICBTCs using the Objective Synoptic Analysis Technique (OSAT) and the above definitions. First, a total of 255 pairs of ICBTCs, which accounted for 60.6% of the total number of BTCs over the Western North Pacific, occurred with an annual average of 4.4. Annual frequency of ICBTCs showed a significant decreasing trend during 1960-2017. The longest duration of ICBTCs was 10 days, while durations concentrated in 1 day, 2 days and 3 days, accounting for 18.8%, 29.4% and 24.3%, respectively. In terms of geographical distribution, the ICBTCs mainly occurred over the range of 112°~138°E, 12°~30°N, with frequent zones in the oceans around the northern Philippines. In addition, both annual mean frequency and precipitation of the ICBTCs decrease from the southeast coast areas to the northwest inland regions, with severely-affected areas being the Taiwan Island, the Southeast Coast and the South Coast, and the most-severely-affected area being the Taiwan Island. Further analyses reveal that the average position of the two TCs on the maximum daily precipitation day during the ICBTCs period show an east-west distribution pattern, with the western TCs and the eastern TCs locating in the southwest wind water vapor channel of the East Asian Summer Monsoon and the warm-wet air flow of the southeast-wind on the southwest side of the subtropical high. This situation is beneficial to the western TCs obtaining water vapor from the southwest wind water vapor channel, and to the eastern TCs conveying water vapor to the western TCs, and then as a result, to the heavy rainfall over the Taiwan Island, the Southeast and the South Coasts of China caused by the western TCs. |
| |
| Keywords: | Activity of ICBTC Climatic characteristics Precipitation of ICBTC |
|
| 点击此处可从《地球科学进展》浏览原始摘要信息 |
| 点击此处可从《地球科学进展》下载免费的PDF全文 |
|
