2000-2015年青藏高原切变线统计特征分析（英文）

Statistical Characteristics Analysis of the Shear Line in the Qinghai-Tibet Plateau from 2000 to 2015

为探讨高原切变线系统的变化特点及与中国降水的关系,利用青藏高原低涡切变线年鉴统计分析2000-2015年高原切变线的活动特征及其影响下的降水特征。结果表明,高原切变线发生源地主要集中在西藏中部及东部、青海西南部地区,高频地区位于那曲县附近。2000-2015年高原切变线共生成591次,移出87次,移出几率为14.72%;高原切变线的出现和移出均以高原东部切变线为主。夏半年高原切变线活跃程度远高于冬半年,在夏季5-9月切变线出现及移出次数较多;8月达到峰值。高原切变线在四川省内移出次数最多,占65.52%。63.45%的高原切变线生命史在12 h内;对于移出高原的切变线,78.16%生命史在24～36 h内;移出高原的切变线生命史普遍长于未移出高原的切变线。影响高原切变线移出的系统中,西风槽的影响率最高。东移出高原的切变线影响下的降水范围更广,降水强度更大。

To investigate the characteristics of the plateau shear lineand its relationship with precipitation in China,the Tibetan Plateau Vortex and Shear Line Yearbookare used to analyze the activity characteristics of the plateau shear lineand the precipitation characteristics under the influence of the plateau shear line from 2000 to 2015. The results show that the source region of the plateau shear line mainly concentrates in the central and eastern part of Tibet,and the southwest of Qinghai Province,the high frequency region is located near Nagqu County.From 2000 to 2015,there are a total of 591 plateau shear linesand removed 87 times,the probability of removal is 14. 72%. The plateau shear line appeared and removed mostly in the eastern part of the plateau. The activity degree of plateau shear line in the summer half year is much higher than that in winter half year.The period from May to September is the fastigium for the plateau shear line occurrence and the removal times,and it reaches the peak in August.The removal number of the plateau shear line in Sichuan Province is the largest,accounting for 65.52%. 63. 45% of the plateau shear line＇s lifetime is within 12 h. For the removing plateau shear line,78.16% of its lifetime is within 24 ～ 36 h.The life history of the removing shear line is generally longer than non-removing shear line.Whathas the largest influencein the plateau shear line removalin the systemsisthewesterly trough.The eastern removing shear line will lead to a wider range of precipitation and greater precipitation intensity than non-removing.