测风激光雷达对孤立雷暴引发湿下击暴流的结构分析  

Structural analysis of wet downburst triggered by isolated thunderstorms based on wind LiDAR

作　　者：王楠 程海艳 尹才虎 WANG Nan;CHENG Haiyan;YIN Caihu(Meteorological Center,Xinjiang Air Traffic Management Bureau,Civil Aviation Administration of China,Urumqi 830016,China)

机构地区：[1]中国民用航空局新疆空管局气象中心,乌鲁木齐830016

出　　处：《激光技术》2024年第5期643-650,共8页Laser Technology

基　　金：民航新疆空管局科技项目(民航新疆空发[2023]47号)。

摘　　要：为了揭示中γ尺度孤立单体雷暴引发的下击暴流的风场结构及成因,采用多源数据结合的方法着重分析了激光雷达资料,对2022-06-25发生在乌鲁木齐机场跑道入口端的一次湿下击暴流进行了结构场剖析,取得了能够表征下击暴流发生发展过程的数据。结果表明,本次过程发生在西北气流控制且有明显风场辐合和冷空气堆积的背景下,中低层切变线和地面中尺度辐合线是此次过程的触发机制;两个气象雷达体扫呈现了孤立雷暴的初生-发展-成熟阶段,及回波中心下降接地引发湿下击暴流的过程;强的不稳定能量是造成此次强天气过程的关键;强降水发生前6 min不稳定能量积攒至最强,随后能量迅速释放,强下沉气伴短时强降水,触发了湿下击暴流;测风激光雷达可观测到雷暴高压始发的中心位置和反气旋特征、大风区和外流边界,明确了高压区域大小和强度变化,对强下沉气流爆发的时间和强度指征明显。这些结果为研究雷暴单体引发下击暴流的结构提供了有力支持,提高了民航精细化服务的能力。In order to reveal the wind field structure and cause of the downdraft generated by a mesoscale isolated thunderstorm in the centralγregion,a method of combining multi-source data was adopted,with a focus on the analysis of the light detection and ranging(LiDAR).A structural field analysis of a wet downdraft that occurred at the entrance end of the runway at Urumqi Airport on 2022-06-25 was carried out,and data that can characterize the development process of the downdraft were obtained.The results showe that under the background of northwest airflow convergence and cold air accumulation,the mid-low level shear line and the ground mesoscale convergence line were the triggering mechanisms for this process.Two Doppler radar volume scans present the process of the initial development and mature stages of the isolated thunderstorm,with the the process of moist downbursts caused by echo center descending and strong echoes reaching the ground.Strong unstable energy was the key factor causing this severe weather process.The unstable energy accumulated to its maximum 6 min before the occurrence of heavy precipitation,and then rapidly released,accompanied by short-term intense precipitation and triggered the wet downdraf.The center position and anticyclonic characteristics of the thunderstorm high pressure initiation were observed through the wind LiDAR,the area of strong winds and the outer boundary of outflow were then estimated,the size and intensity changes of the high-pressure area were clarified.It provided clear indications for the timing and intensity of the outbreak of the downdraft,and provided strong support for the analysis of the structure of thunderstorm-induced downdrafts,as well as fine warning for flight safety.

关 键 词：激光技术 湿下击暴流 测光激光雷达 风场结构特点分析 飞行安全 

分 类 号：TN958.98[电子电信—信号与信息处理] P412.25[电子电信—信息与通信工程]