一次秋季对流性暴雨的双偏振雷达回波特征分析  

Analysis of Dual-polarization Radar Echo Characteristics of a Convective Rainstorm in Autumn

作　　者：毛倩 宋光勇 董文韬 丁泳尹 白慧 MAO Qian;SONG Guangyong;DONG Wentao;DING Yongyin;BAI Hui(Qiandongnan Miao and Dong Autonnomous Prefecture Meteorological Bureau of Guizhou Province,Kaili 556000,China;Majiang Meteorological Bureau of Guizhou Province,Majiang 557600,China)

机构地区：[1]贵州省黔东南苗族侗族自治州气象局,贵州凯里556000 [2]贵州省麻江县气象局,贵州麻江557600

出　　处：《中低纬山地气象》2023年第3期38-44,共7页Mid-low Latitude Mountain Meteorology

基　　金：黔东南州科技计划项目(黔东南科合基础[2022]09号):基于区域自动站的黔东南“两山”地区致灾暴雨研究。

摘　　要：该文利用黔东南榕江C波段双偏振多普勒天气雷达资料、常规观测资料及地面加密自动站观测资料等,对2021年9月6日傍晚到夜间贵州东部地区出现的对流性暴雨天气过程的环流背景、影响系统和雷达回波特征进行总结分析。结论如下:(1)此次天气过程是在副高西伸北抬形成高压坝的背景条件下,中高纬冷涡低槽与高原东移的短波槽在四川东部同位相合并加强东移,引导冷空气从西北路径和东北路径两面夹击影响贵州东部地区,配合长时间稳定维持的南北向低空切变线,共同触发不稳定能量强烈释放,产生对流性暴雨天气。(2)带状对流回波东段东移至铜仁、黔东南州境内后逐渐转为片状积层混合降水回波,并长时间稳定维持少动。暴雨发生期间,回波具有明显的低质心高效率的热带暖云降水回波特征;VIL值在10~30 kg·m^(-2)之间,局地出现明显的跃增现象;低仰角径向速度图上长时间维持明显的风场辐合。(3)此次过程雷达偏振参量具有产生强降水的特征,最大Z H在40~60 dBz之间,Z DR在0.2~5 dB之间,K DP范围为0.5~7.0°·km^(-1),CC在0.9~0.98之间,最大时≥0.98。In this paper,using the C-band dual polarization doppler weather radar data of Rongjiang in southeast Guizhou,conventional observation data and ground densified automatic station observation data,the circulation background,influence system and radar echo characteristics of the convective rainstorm weather process in eastern Guizhou from the evening to the night on September 6,2021 are summarized and analyzed.It is concluded that,(1)this weather process is under the background that the subtropical high extends westward and uplifts northward to form a high-pressure dam.The mid high latitude cold vortex trough and the short wave trough moving eastward from the plateau are in the same phase in eastern Sichuan,strengthening and moving eastward,leading the cold air to strike the eastern Guizhou from both sides of the northwest path and the northeast path,together with the south-north low level shear line that has been stably maintained for a long time,to jointly trigger the strong release of unstable energy and generate convective rainstorm weather.(2)After moving eastward to Tongren and Qiandongnan Prefecture,the eastern segment of the band convective echo gradually turns into the mixed precipitation echo of sheet cumulus and stratocumulus,which is stable and less dynamic for a long time.During the rainstorm,the echo has obvious characteristics of tropical warm cloud precipitation echo with low centroid and high efficiency;the VIL value is between 10 and 30 kg·m^(-2),and there is obvious jump phenomenon locally;the obvious wind convergence is maintained on the low elevation radial velocity map for a long time.(3)The radar polarization parameters in this process have the characteristics of producing heavy precipitation,the maximum Z H is between 40 and 60 dBz,Z DR is between 0.2 and 5 dB,K DP ranges from 0.5 to 7.0°·km^(-1),CC is between 0.9 and 0.98,and≥0.98 at the maximum.

关 键 词：C波段双偏振雷达 偏振参数 对流性暴雨 回波特征 

分 类 号：P412.25[天文地球—大气科学及气象学] P458.1