| 摘要: |
| 本文通过低频磁脉冲闪电探测系统和双偏振雷达联合观测结果,针对2019—2020年青岛沿海地区发生的5次雷电灾害天气,研究了雷暴的闪电始发位置与微物理参数之间的关系,结果如下:(1)闪电主要始发于组合反射率大于45 dBz的强回波区,地闪的接闪位置距离主雷暴云系可达10~30 km左右。闪电始发区域组合反射率的中位数为55 dBz,液态水含量的中位数为37 kg/m2。(2)闪电始发位置的双偏振雷达水平反射率主要集中于35~45 dBz,差分反射率主要集中在1.5~2.5 dB,相关系数集中于0.97~0.99。大部分雷电始发于0℃等温线和–10℃等温线之间,位于液态水、湿霰和干霰混合相态粒子区。部分雷电过程发生于湿霰区的中上部,这种情况一般差分反射率值很大。(3)在–10~0℃等温层之间存在相关系数大值区且相态粒子为湿霰粒子,说明为过冷水区。过冷水区中极易产生大直径的霰粒,在强上升气流的作用下,大直径霰粒与冰晶碰撞从而极易发生闪电过程。 |
| 关键词: 三维闪电定位 双偏振雷达 微物理特征 相态识别 |
| DOI：10.11759/hykx20221225001 |
| 分类号:P401 |
| 基金项目:2019年度山东省气象局重点项目(2019sdqxz08); 2021年度山东省自然科学青年基金(ZR2021QD023); 国家自然科学基金青年项目(42205078) |
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| Characterization of the microphysical parameters associated with lightning initiation in thunderstorms over the Qingdao coastal area |
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ZHANG Yuanyuan1, SUN Hao2, WANG Peng3, MENG Fanhui1, LIU Zhao1, LUAN Zaimao1
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1.Qingdao Technology Research Center for Meteorological Disaster Prevention, Qingdao Meteorological Bureau, Qingdao 266003, China;2.CMA Meteorological Observation Centre, Beijing 100081, China;3.Weifang Meteorological Bureau, Weifang 261000, China
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| Abstract: |
| This study used the observation data of a three-dimensional lightning-pulse location system comprising seven low-frequency magnetic sensors and dual-polarization radar to analyze five lightning events in the Qingdao coastal area from 2019 to 2020 and demonstrate the relationship between microphysical parameters and the initial lightning strike position. The results show that (1) most lightning strikes initially occurred in strong echo regions with composite reflectivity greater than 45 dBz. The distance between the cloud-to-ground lightning arrester could reach approximately 10–30 km. The median of vertically integrated liquid water was 37 kg/m2. (2) At the initial lightning strike position, the radar’s horizontal reflectivity was mainly 35–45 dBz. Further, the radar’s differential reflectivity was mainly 1.5–2.5 dB, and the correlation coefficient ranged from 0.97 to 0.99. Most lightning strikes were initiated between a thermal layer with temperatures −10 ℃ to 0 ℃comprising rain, wet graupel, and dry graupel. Some lightning strikes were initiated in the middle and upper parts of the wet graupel region, which generally showed a large value of ZDR. (3) Wet graupel existed in the isothermal layer with temperatures −10℃ to 0 ℃ in a supercooled water zone, and the radar’s horizontal reflectivity and correlation coefficient were higher. Large-diameter graupel particles were more likely to be produced in the supercooled water zone. With strong updrafts, large-diameter graupel particles collided with ice crystals that were prone to lightning processes. |
| Key words: lightning 3-D location polarimetric radar micro-physical characteristics hydrometer dentification |
