基于风廓线雷达的湖北梅雨期暴雨中小尺度特征  

Meso and small-scale characteristics of heavy rain during Meiyu period in Hubei based on wind profile radar

作　　者：苟阿宁 吴翠红[2] 王玉娟[3] 杜牧云 刘文婷[2] 冷亮 邓红[2] GOU Aning;WU Cuihong;WANG Yujuan;DU Muyun;LIU Wenting;LENG Liang;DENG Hong(Wuhan Institute of Heavy Rain,CMA,Wuhan 430205,China;Wuhan Central Meteorological Observatory,Wuhan 430074,China;Meteorological Disaster Prevention Technology Center in Qinghai Province,Xining 810001,China)

机构地区：[1]中国气象局武汉暴雨研究所,湖北武汉430205 [2]武汉中心气象台,湖北武汉430074 [3]青海省气象灾害防御技术中心,青海西宁810001

出　　处：《干旱气象》2022年第1期84-94,共11页Journal of Arid Meteorology

基　　金：国家自然科学基金项目(41620104009);2019年湖北省气象局研究型业务发展专项《无缝隙短时临近预报预警技术研究与应用》(2019YJ01-1);湖北省气象局面上项目(2021Y01)共同资助。

摘　　要：针对2016年湖北梅雨期3次(“6·19”、“7·5”和“7·19”)暴雨过程,首先对比了汉口站探空数据与汉口、咸宁两个风廓线雷达站水平风速、风向,发现“6·19”和“7·5”过程汉口风廓线雷达站3 km以下水平风速和探空数据较为接近,而3次过程中咸宁风廓线雷达站8 km以下水平风向、风速和汉口站探空数据基本吻合。在此基础上利用风廓线雷达资料并结合常规、加密自动气象站资料,对3次过程中水平风场、平均垂直速度及其变率、水平风速垂直切变、大气折射率结构常数(C_(n)^(2))等进行分析。结果表明:(1)降水开始前西南风速明显增大,中层干冷空气入侵和地面冷池形成的中尺度偏东气流是“6·19”过程50站出现大于等于17.2 m·s^(-1)大风的主要原因,“7·5”和“7·19”过程西南急流长时间维持及1 km以下的偏东气流则是短时强降水持续时间较长的诱因;(2)梅雨期暴雨期间风廓线雷达观测的水平风速垂直切变、平均垂直速度及其变率随高度变化较小,较强上升运动区域主要集中在4 km高度以下;(3)C_(n)^(2)显示强降水发生前大气水汽含量有一增加过程,且整层水汽含量深厚,C_(n)^(2)大值区的消失对应降水结束。In view of three rainstorm processes(“6·19”,“7·5”and“7·19”processes)during Meiyu period in Hubei Province in 2016,firstly,the sounding data of Hankou station were compared with the horizontal wind speed and wind direction from Hankou and Xianning wind profile radar stations.It was found that the horizontal wind speed below 3 km from Hankou wind profile radar station was close to sounding data in the“6·19”and“7·5”processes;the horizontal wind direction and wind speed below 8 km from Xianning wind profile radar station were basically consistent with the sounding data in the three processes.Combined with the data of conventional and encrypted automatic weather stations,the horizontal wind field,average vertical velocity and its variability,vertical shear of horizontal wind speed and atmospheric refractive index structure constant C_(n)^(2) were analyzed by using wind profile radar.The results are as follows:(1)The southwest wind speed increased significantly before the beginning of precipitation.The invasion of dry and cold air in the middle layer and the mesoscale easterly air flow formed by the ground cold pool were the main reasons for the occurrence of strong winds with more than and equal to 17.2 m·s^(-1) at 50 stations in the“6·19”process,and the long-term maintenance of the southwest jet and the easterly air flow below 1 km in the“7·5”and“7·19”processes were the inducements for the long duration of short-term heavy precipitation.(2)The vertical shear of horizontal wind speed,the variation of average vertical velocity and its variability with height observed by wind profile radar were small,and strong upward movement was mainly concentrated below 4 km height.(3)Before the occurrence of heavy precipitation,the atmospheric water vapor content had an increasing process,and the water vapor content in the whole layer was deep.The disappearance of the large value area of C_(n)^(2) corresponded to the end of precipitation.

关 键 词：梅雨期暴雨 风廓线雷达 中小尺度系统 

分 类 号：P458.121.1[天文地球—大气科学及气象学]