四川省夏季暴雨典型环流形势分析

Analysis of the Typical Circulation Situation of Summer Rainstorms in Sichuan Province

摘要: 为进一步研究四川地区暴雨的特点，选取四川省126个气象站从2001~2019年共19年6~8月站点降水资料以及FNL一日四时再分析资料，网格距1˚ × 1˚，通过合成分析等方法，对四川省典型暴雨的高低空环流形势进行了详细研究，结果表明：1) 6月暴雨中心出现在遂宁，南亚高压移上高原，川东位于500 hPa槽前，低空存在切变线和气旋式环流，水汽来自南海。2) 7月暴雨中心出现在万源，南亚高压东伸至四川，川东位于500 hPa槽前，四川位于副高边缘西侧，低空水汽来自孟加拉湾和南海。3) 8月暴雨中心出现在青川，南亚高压西撤，川东位于500 hPa槽前，副高继续西伸至四川，低空水汽来自孟加拉湾和南海。

Abstract: In order to further study the characteristics of heavy rain in Sichuan, the precipitation data of 126 meteorological stations in Sichuan province from June to September in 19 years from 2001 to 2019 and the FNL reanalysis data at 4 o’clock a day were selected, and the grid distance was 1.0˚ × 1.0˚. By means of synthetic analysis and other methods, the high-low circulation situation of typical heavy rain in Sichuan province was studied in detail. The results show that: 1) The rainstorm center appeared in Suining in June, the SAH moved up to the plateau, the east Sichuan was in front of the trough, there were shear lines and cyclonic circulation at low altitude, and water vapor came from the South China Sea. 2) In July, the rainstorm center appeared in Wanyuan, the SOUTH Asian High extended eastward to Sichuan, the east of Sichuan was in front of the trough, and Sichuan was in the west of the edge of the subtropical high. Low-level water vapor came from the Bay of Bengal and the South China Sea. 3) In August, the rainstorm center appeared in Qingchuan, the SAH retreated westward, the eastern Sichuan was in front of the trough, and the subtropical high continued to extend westward to Sichuan. Low-level moisture is coming from the Bay of Bengal and the South China Sea.