基于多波段雷达观测的浙江一次飑线演变结构特征分析  

Analysis of Evolution Structure of a Squall Line in Zhejiang Province Based on Multi-band Radar Observation

作　　者：钱卓蕾 严佩文 李锋 黄滢 QIAN Zhuolei;YAN Peiwen;LI Feng;HUANG Ying(Shaoxing Meteorological Observatory,Zhejiang,Shaoxing 312000;Shaoxing Meteorological Bureau,Zhejiang,Shaoxing 312000;Shaoxing Meteorological Service Center,Zhejiang,Shaoxing 312000)

机构地区：[1]浙江省绍兴市气象台,绍兴312000 [2]浙江省绍兴市气象局,绍兴312000 [3]浙江省绍兴市气象防灾减灾中心,绍兴312000

出　　处：《气象科技》2024年第5期681-691,共11页Meteorological Science and Technology

基　　金：浙江省气象局重点项目(2022ZD01)资助。

摘　　要：本文利用S波段双偏振雷达、X波段相控阵雷达数据及其反演风场、闪电定位、ERA5再分析资料等,对2022年7月21日发生在浙江中北部一次飑线的特征进行了分析。结果表明:飑线发生在副高控制下,高空冷涡底部干冷空气侵入造成不稳定层结以及较高的能量和充足的边界层水汽,是飑线发生的有利环境条件。飑线初始对流形成于杭州东部和西北部南北风的辐合线中,强风暴合并后风暴尺度出现明显增长并形成飑线,杭州湾南岸的辐合中心、垂直风速差的增强有利于飑线迅速发展,当垂直风速差与冷池传播速度相当时,飑线发展成熟;大风主要出现在云闪密集区。X波段相控阵雷达可以精细探测极端大风发生前后飑线强单体的垂直结构:成熟阶段强单体中差分反射率和差分相移率柱的发展代表风暴加强,回波质心迅速下降可指示地面大风,降水粒子下落拖拽进一步加强地面风力。In this paper,the characteristics of a squall line that occurred in central and northern Zhejiang on 21 July 2022 are analyzed by using S-band dual-polarization radar,X-band phased array radar data,wind retrieval,lightning location and ERA5 reanalysis data.The results show that:The squall line affected the area for up to 6 hours,causing large-scale winds of 8-10 levels along the way.The pressure surge ahead of the strong winds and precipitation at the extremely strong wind station served as a precursor to extreme winds.The squall line occurred under the control of the subtropical high.The dry and cold air at the bottom of the high-level cold vortex invaded,with the high-energy and high humidity in the low-level forming an unstable layer structure,which provided favourable environmental conditions for the generation and maintenance of the squall line.The observation of the S-band dual polarisation radar showed that the evolution of squall lines went through processes such as initiation,merging,growth,maturity,and disappearance.The initial convection was formed in the mesoscale convergence lines in the northwest and east of Hangzhou.Strong storms in the northwest of Hangzhou moved faster than those in the east,leading to the rapid merging and development of the two into squall lines.After the squall line entered the south bank of the Hangzhou Bay,the storm outflow overlapped with the mesoscale convergence centre on the south bank of the Hangzhou Bay,leading to the rapid development of the squall line to its mature stage.In addition,the growth of vertical wind shear was also conducive to the rapid development of the squall line.Strong winds often occurred in areas with dense cloud flashes.The X-band phased array radar could finely detect the vertical structure of strong cells before and after extreme winds occurred.The development of ZDR and KDP columns in mature strong cells represented storm intensification,and the rapid decline of the echo centroid could indicate surface winds.The falling and dragging of precipit

关 键 词：飑线 垂直风速差 双偏振参量 相控阵雷达 风场反演 

分 类 号：P458.2[天文地球—大气科学及气象学]