2020年梅雨期上海一次强降水过程垂直结构的综合观测分析  

Observational analysis of vertical structure of a heavy precipitation event in Shanghai during Meiyu period in 2020

作　　者：傅新姝 顾问 彭杰 麻炳欣 郭巍 王晓峰 岳彩军 张燕燕 薛昊[3] FU Xinshu;GU Wen;PENG Jie;MA Bingxin;GUO Wei;WANG Xiaofeng;YUE Caijun;ZHANG Yanyan;XUE Hao(Shanghai Ecological Forecasting and Remote Sensing Center,Shanghai 200030;Baoshan Meteorological Service,Shanghai 200030;Shanghai Meteorological Information and Technology Support Center,Shanghai 200030)

机构地区：[1]上海市生态气象和卫星遥感中心,上海200030 [2]上海市宝山区气象局,宝山200030 [3]上海市气象信息与技术支持中心,上海200030

出　　处：《暴雨灾害》2020年第6期658-665,共8页Torrential Rain and Disasters

基　　金：上海市科学技术委员会科研计划项目(18DZ1200405);上海市青年科技英才扬帆计划(20YF1443400);国家自然科学基金项目(41905007,41875059)。

摘　　要：基于微波辐射计、微雨雷达、风廓线雷达和毫米波云雷达获得的高时空分辨率多源新型遥感探测资料,对上海梅雨期一次强降水过程(2020年6月15日)的大气热力、动力、云雨等垂直结构特征进行了分析。主要结论如下:(1)降水发生前一日(6月14日)上午,强西南风为上海地区输送了大量水汽,对流层中低层水汽明显增多、气温偏高,大气不稳定性增加,K指数在降水前10多个小时逐渐增至35℃甚至更高;降水之后,对流层低层气温下降、水汽减少。(2)此次降水过程云层较深厚,主要降水时段云层厚度基本都维持在12 km以上,最厚可达14 km,融化层位于约4.7 km高度。(3)降水各阶段对应的云雨结构特征差异较大。降水前期,强回波垂直方向集中在3 km以下,且时间上间歇出现;降水中期,云体融化层连续且稳定,强回波区持续出现,且垂直方向扩展至4 km及以上,雨滴下降速度稳定维持在6 m·s^-1以上;降水后期,云顶高度下降至9 km及以下,降水回波减弱,弱降水特征明显。Using the observations with high temporal and spatial resolution from multiple ground-based remote sensors such as microwave radiometer(MWR),micro rain radar(MRR),wind profiler and millimeter cloud radars,a synergistic analysis was conducted for the features of vertical structure in thermodynamics,dynamics and other aspects of atmospheric characteristics for a heavy precipitation event in Shang⁃hai on 15 June 2020.The main results are as follows.(1)Southwest wind dominates in the middle and lower levels of troposphere before the rainfall occurs,which provides plenty of water vapor for the Shanghai area and results in a significant increase of moisture in this area.High moisture and temperature in low level of the troposphere lead to continuous increase of the atmospheric instability before the rainfall.And the K index calculated based on MWR observations reaches 35℃and even higher around 10 hours before the rainfall.When the rainfall oc⁃curs,temperature drops and moisture decreases in low level.(2)Deep cloud is observed in this event.The cloud layer thickness is generally larger than 12 km and the largest cloud thickness is as large as 14 km.The melting layer is located around height of 4.7 km.(3)Distin⁃guished features of rainy cloud systems can be observed at the different stages of rainfall.The strong echoes of raindrops concentrate below 3 km intermittently at the early stage.The melting layer is stable,and the strong echoes of raindrops occur continuously and extend vertically to over 4 km with raindrop's falling velocity of 6 m·s-1 at the middle stage.The cloud top reduced to 9 km and the echoes of raindrops get weaker,showing an obvious feature of weak rainfall at the final stage.

关 键 词：强降水 垂直结构 观测分析 梅雨期 上海 

分 类 号：P458.121.1[天文地球—大气科学及气象学]