阿克苏地区一次强对流天气过程的地闪活动特征分析  

Activity characteristics of the cloud-to-ground lightning in a severe convective weather event in Arksu of Xinjiang

作　　者：刘兆旭 陈金根 刘晶[1] 周玉淑 李建刚[1] LIU Zhaoxu;CHEN Jingen;LIU Jing;ZHOU Yushu;Li Jiangang(Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002;Xinjiang Center of Lightning Protection and disaster reduction,Urumqi 830002;Laboratory of Cloud-Precipitation Physics and Severe Storms,Institute of Atmospheric Physics,Chinese Academy of Science,Beijing 100029;School of Earth Sciences,University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国气象局乌鲁木齐沙漠气象研究所,乌鲁木齐830002 [2]新疆维吾尔自治区防雷减灾中心,乌鲁木齐830002 [3]中国科学院大气物理研究所云降水物理与强风暴实验室,北京100029 [4]中国科学院大学地球科学学院,北京100049

出　　处：《暴雨灾害》2022年第6期640-650,共11页Torrential Rain and Disasters

基　　金：华云基金项目(HYJJ005);国家自然科学基金项目(41875023);新疆维吾尔自治区高层次人才天池计划项目(2019)。

摘　　要：2017年6月7日阿克苏地区出现一次强对流天气过程,其中2个α中尺度对流系统(MCS)及其合并发展造成多站大风、冰雹和短时强降水。为探明该过程地闪分布及其与云顶亮温(TBB)、雷达回波和对流系统发展的关系,加深对新疆强对流天气中地闪活动规律和特征的认识,利用新疆地闪监测定位系统数据、卫星TBB资料、C波段多普勒天气雷达资料等,分析了此次强对流天气过程地闪活动特征。结果表明:(1)对流层低层和中层明显增湿,低空中尺度切变线稳定维持,使得地闪集中分布在低空切变线暖平流一侧。(2)该过程以负地闪活动为主,地闪强度由西向东呈增强趋势,地闪强度与地闪密度分布存在一定的负相关,地闪次数跃增和正地闪占比下降与地面大范围强风有着较好的相关性。(3)地闪多发生在TBB≤-40℃云区内,地闪次数与TBB≤-40℃云团面积和最低TBB分别呈正相关和负相关。(4) MCS影响期间负地闪和正地闪多发生在5~20 dBz和10~15 dBz回波区内;对流发生发展和成熟阶段垂直积分液态水含量(VIL)峰值较地闪次数剧增提前12~20 min出现。地闪次数与回波顶高对流发生发展阶段呈正相关关系,成熟阶段呈负相关关系。A severe convective weather event occurred in the Arksu area of Xinjiang on 7 June 2017. In this event, two α-mesoscale convection systems(MCS) and their merging and development caused gale, hailstorm, and short-time heavy precipitation at several stations. The objective of this study is to determine the distribution characteristics of cloud-to-ground(CG) lightning and its relationship with cloud top brightness temperature(TBB) and the development of radar echo and convective system in this event, and to deepen the understanding of the characteristics of CG lightning activity. Using the lightning locating data over Xinjiang, the TBB data from FY-4A, the Doppler weather radar data, and other data, we conducted an analysis of the characteristics of CG lightning activity during this event. The results show that(1) the CG lightning activity concentrates on the warm advection side of the low-level shear line due to the obviously wetter lower and middle troposphere and the stability and continuance of the mesoscale shear line in the lower troposphere.(2) During the event, the CG lightning is mainly negative CG lightning, and its intensity is higher in the east and lower in the west of the Arksu area. There is a certain negative correlation between the CG lightning intensity and the CG lighting density. The large-scale strong wind near the ground has a strong linear correlation with the leap of CG lightning frequency and the decreasing of positive CG lightning proportion.(3) Most of CG lightning distributes in the areas where TBB is less than or equal to-40 ℃. The frequency of CG has positive and negative correlations with the cloud cluster areas with TBB≤-40 ℃ and the TBB minimum value, respectively.(4) During the period affected by MCS, most of the negative and positive CG lightning occur in the echo areas of 6-20 d Bz and 11-15 dBz, respectively. Both the generation and development and the mature stages of convection, the peak value of vertical integrated liquid water content(VIL) appears 12-20 min earlier tha

关 键 词：强对流 地闪 云顶亮温 雷达回波 低空急流 

分 类 号：P458.11[天文地球—大气科学及气象学]