两种不同路径台风对四川东北部持续性暴雨影响对比分析

Comparative Analysis on the Effect of Two Typhoons with Different Paths in Persistent Rainstorm of Northeast Sichuan

利用NCEP时间间隔为6 h的1°×1°再分析资料,对比分析了两种不同路径的台风"康森"和"丹娜丝"分别对2010年7月16—18日和2019年7月16—18日四川东北地区持续性暴雨的影响,结果发现:(1)台风"康森"和"丹娜丝"通过阻挡副高东退间接阻挡四川东北地区的高空低值系统东移出四川,延长了降雨的时间。(2)台风"康森"在西进登陆后,对2010年7月16—18日暴雨造成了直接影响,其外围东南风急流与副高西侧偏南气流贯通,向四川盆地输送了充沛的水汽和能量,使得西南低涡在四川东北地区维持发展。台风"丹娜丝"并未对2019年7月16—18日暴雨造成了直接影响,其水汽和能量主要依靠副高外围的偏南气流输送。(3)台风"康森"对2010年7月16—18日暴雨的地面中尺度辐合系统扰动、发展、移动方向有明显影响,而台风"丹娜丝"对2019年7月16—18日暴雨的地面中尺度辐合系统影响相对较弱。(4)偏西路径台风"康森"对四川东北地区持续性暴雨的影响比偏北路径台风"丹娜丝"要大得多,导致2010年7月16—18日暴雨强度及灾害程度要比2019年7月16—18日强。

By using the 1 °×1 ° reanalysis data of NCEP time interval of 6 h to analyze the effect of two different typhoon "Conson"and"Danas"on rainstorm in the Northeast Sichuan on July 16 th-18 th,2010 and July 16 th-18 th,2019. The results showed that:(1)Typhoon"Conson"and"Danas"indirectly prevent the high-altitude low-value system in Northeast Sichuan from moving out of Sichuan by blocking the retreat of the subtropical high to the east,thus prolonging the rainfall time.(2)After "Conson"made landfall and moved toward west,it had a direct impact on the rainstorm of July 16 th-18 th,2010. The jet of southeast in the periphery of typhoon connected with the south-to-south airflow on the west side of the subtropical high,and transported abundant water vapor and energy to the Sichuan Basin,which made the southwest vortex maintain its development in the Northeast Sichuan. Typhoon "Danas" not directly transported water vapor and energy to the rainstorm on July 16 th-18 th,2019. The water vapor and energy were mainly transported by the southerly airflow around the subtropical high pressure.(3)Typhoon"Conson"had a significant impact on the disturbance,which resulted in development and movement direction of surface mesoscale convergence system of rainstorm on July 16 th-18 th,2010,while typhoon"Danas"had a relatively weak impact on the surface mesoscale convergence system of rainstorm on July16 th-18 th,2019.(4) The impact of typhoon "Conson"in the west path on the continuous rainstorm in Northeast Sichuan was much larger than that of typhoon"Danasi"in the north path,which resulted in the intensity and disaster of the rainstorm on July 16 th-18 th,2010 was stronger than that on July 16 th-18 th,2019.