基于TRMM PR探测资料的青藏高原东坡降水结构特征分析  

Analysis on the characteristic of precipitation structure on the eastern slope of the Qinghai-Tibet Plateau based on TRMM PR data

作　　者：李函璐 孙礼璐 杨柳 罗晶 傅云飞[1] LI Hanlu;SUN Lilu;YANG Liu;LUO Jin;FU Yunfei(School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026)

机构地区：[1]中国科学技术大学地球和空间科学学院,合肥230026

出　　处：《暴雨灾害》2022年第4期384-395,共12页Torrential Rain and Disasters

基　　金：国家重点研发计划(2018YFC1507200,2017YFC1501402);国家自然科学基金项目(91837310,41075041);安徽省重点研究与开发计划(201904a07020099)。

摘　　要：利用热带测雨卫星(TRMM)探测资料和ERA5再分析资料,研究了2006年7月6日发生在青藏高原东坡的一次强降水过程,并在此基础上分析了青藏高原东坡夏季(6—8月)的降水结构特征。研究结果表明:青藏高原东坡较强降水个例发生在低层辐合、高层辐散的降水环境背景场中,雨带呈东北-西南分布,最大降水强度超过20 mm·h^(-1)。对流降水回波顶高超过17 km,层状降水回波顶高低于15 km,6.5 km高度存在亮带,且外形也似非高原地区的层状降水垂直结构。统计分析表明在高原东部偏南区、高原东部与四川盆地交界区南部的夏季降水频次高,而在高原东部偏北及四川盆地的降水频次、对流和层状降水频次均比上述地区小;多年夏季的日均降水量分布大体与降水频次分布类似。降水反射率因子的垂直结构具有地域性特点,高原东部偏南和偏北区的回波垂直结构相似,因受到地形高度的压缩,其降水垂直结构与非高原地区的不同;而高原东部与四川盆地交接区的降水垂直结构外形,介于高原与非高原之间;四川盆地的对流降水和层状降水垂直结构与中国东部平原及热带副热带洋面的相近,但层状降水的亮带高度高出1 km。Using the TRMM data and ERA5 reanalysis data,a heavy precipitation case in the eastern slope of the Qinghai-Tibet Plateau on July 6,2006 was investigated.Based on the investigations,the precipitation structure characteristics in summer(June-August)over the east⁃ern slope of the Qinghai-Tibet Plateau were analyzed.Results indicate that the heavy rain case on the eastern slope of the Qinghai-Tibet Pla⁃teau occurred in the typical circulation with convergence at the lower level and divergence at the upper level.The rain belt extends from northeast to southwest with the maximum rain rate over 20 mm·h^(-1).The echo top height of convective precipitation is more than 17 km while the echo top height of stratiform precipitation is no more than 15 km.There exists bright band structure at 6.5 km which is similar to the verti⁃cal structure of the stratiform precipitation on the non-plateau region.The statistical analysis shows that the summer precipitation frequency on the south-eastern Qinghai-Tibet Plateau and the connection area between eastern plateau and southern Sichuan Basin are high.In con⁃trast,the frequency of the stratiform and convective precipitation are low on the north-eastern plateau and Sichuan Basin.The summer daily average precipitation shows similarity with precipitation frequency for the years.The characteristics of vertical structure of precipitation ra⁃dar reflectivity factor are different in the various area.The vertical structures of precipitation radar reflectivity in the south-eastern and north-eastern regions of the Qinghai-Tibet Plateau are similar,but the vertical precipitation structures are different in the non-plateau re⁃gions because of the compression induced by the height of the topography.It is also found that there are some similarities between the verti⁃cal structure of precipitation in the connection area between eastern plateau and southern Sichuan Basin,the plateau and non-plateau regions.The vertical structure of convective precipitation in the Sichuan Basin,eastern

关 键 词：青藏高原东坡 陡峭地形 热带测雨卫星 测雨雷达 降水结构 

分 类 号：P405[天文地球—大气科学及气象学]