湛江2019年4次冰雹双偏振雷达产品应用分析

Analysis of the A pplication of Dual-polarization Radar Products in Four 2019 Hails in Zhanjang

利用MICAPS高空地面资料和湛江S波段双偏振雷达资料对2019年3月6日、4月12日共4次雹暴云团造成的降雹天气过程进行分析。结果表明:1)4次过程均出现高悬强回波、三体散射长钉等降雹强风暴基本雷达特征;2)双偏振雷达基本参量的冰雹识别通常以高水平基本反射率Z_(H)、低的差分反射率Z_(DR)、协相关系数CC作为冰雹主要识别判据。3)4次雹暴云团在入流缺口处有明显的Z_(DR)环和Z_(DR)柱。成熟的雹暴云团强回波区对应Z_(DR)为趋近于0 dB的低值区,低于0.95的CC与趋近于0 (°)/km或为缺测的K_(DP)。4次过程中降雹前1~2 h,雹胚发展的强回波区域对应Z_(DR)常有低值窄带区下延接地。

Using the upper-level and surface data of MICAPS and the data from an S-band dual-polari-zation radar in Zhanjiang,this work analyzes four hail processes that happened on March 6 and April 12,2019 in the area.The results are shown as follows.(1)The four hails all had intense overhang echoes and three-body scatter spikes that characterize intense hail-precipitating storms.(2)High levels of basic reflee-tivity ZH,low difference reflectivity Z_(DR) and the co-correlativity coefficient(CC)are mainly relied on to i-dentify hails through the basic parameters of dual-polarization radars.(3)For the cloud clusters of the four hails,there were clear Z_(DR) rings and Z_(DR) columns at the inflow gaps.A mature hail cloud cluster was ac-companied with a zone of low Z_(DR),which approached 0 dB,a CC that was lower than 0.95 and a KDP that was either close to 0(°)/km or not observed.One to two hours prior to the four hails,the Z_(DR) for an in-tense echo zone of an evolving hail embryo was usually with a narrow low-value strip that extended downward to touch the ground.