X波段双偏振雷达冰雹偏振参量特征分析  

Analysis of Polarization Parameters of Hail in X-band Dual Polarization Radar

作　　者：蔡军 张艳 陈林 柯莉萍 姚振东 CAI Jun;ZHANG Yan;CHEN Lin;KE Liping;YAO Zhendong(Weining Meteorological Bureau,Weining 553100,China;Key Laboratory of Atmospheric Sounding,China Meteorological Administration,Chengdu 610023,China)

机构地区：[1]威宁县气象局,贵州威宁553100 [2]中国气象局大气探测重点开放实验室,四川成都610023

出　　处：《沙漠与绿洲气象》2024年第4期76-82,共7页Desert and Oasis Meteorology

基　　金：中国气象局大气探测重点开放实验室联合基金开放课题(U2021Z02);毕节市气象局登记制项目(BJKD[2023]12-01);毕科合〔2023〕8号;贵州省科技计划项目(黔科合支撑[2023]一般194)。

摘　　要：利用MaXPol双偏振雷达观测的26个雹云单体和冰雹资料进行反演,分析降雹前偏振参量特征和强中心回波顶高变化,并对雹灾最严重的一次过程进行个例分析。结果表明:(1)雷达的冰雹指标为反射率因子Zh>50 dBZ、相关系数ρHV≤0.8、-2 dB<Zdr(差分反射率)约1 dB且强中心回波顶高超过-10℃层。降雹前6-12 min,大冰雹的平均时间是小冰雹的1.6倍。(2)降雹前大、小冰雹强中心回波顶高走势一致但在4-5 min大冰雹强中心回波顶高增长率明显大于小冰雹。(3)只有大冰雹强中心回波顶高能突破-30℃层。(4)个例分析发现强中心与冰雹区不对应,生成发展阶段冰雹区集中位于强中心后侧相关系数环内,悬垂于0--20℃层;成熟阶段冰雹区扩散包含强中心,悬垂的冰雹区坍塌接地,降雹开始。Using the MaXPol dual polarization radar observation of 26 hail cloud cells and hail data for inversion,the characteristics of polarization parameters and changes in strong center echo top height before hail were statistically analyzed,and a case study was conducted on the most severe hail disaster process.The results indicated that:(1)The hail index of the radar was Zh(reflectivity factor)>50 dBZ,ρHV(correlation coefficient)≤0.8,-2 dB<Zdr(differential reflectance)<1dB,and the top height of the strong center echo should at least exceed the-10℃layer.The duration before hail was 6-12 minutes,and the average duration of large hail was 1.6 times.(2)Before the hailstorm,the trend of the top height of the strong center echo in large and small hail was consistent,but the growth rate of the top height of the strong center echo in large hail was significantly greater than that in small hail within 4-5 minutes.(3)Only the strong central echo top of the large hail could break through the-30℃layer.(4)The case study found that the strong center did not correspond to the hail area one by one.During the generation and development stage,the hail area was concentrated in the correlation coefficient ring behind the strong center,hanging in the 0--20℃layer.In the mature stage,the spread of hail areas included a strong center,and the suspended hail area began to collapse to the ground,leading to the onset of hail.

关 键 词：双偏振雷达 冰雹识别 偏振特征 

分 类 号：P412[天文地球—大气科学及气象学]