| 广东一次飑线过程中一个雷暴单体成熟阶段的电荷结构演变特征的数值模拟 |
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| 引用本文： | 甘明骏,郭凤霞,黎奇,刘泽,张坤,蔡彬彬.广东一次飑线过程中一个雷暴单体成熟阶段的电荷结构演变特征的数值模拟[J].热带气象学报,2020,36(4):562-576. |
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| 作者姓名： | 甘明骏 郭凤霞 黎奇 刘泽 张坤 蔡彬彬 |
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| 作者单位： | 南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心/中国气象局气溶胶与云降水重点开放实验室，江苏 南京 210044 |
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| 基金项目： | 国家重点研发计划项目2017YFC1501503国家自然科学基金项目41975003国家自然科学基金项目41875002 |
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| 摘 要： | 为了进一步印证以往观测反推得到的广东地区雷暴云多偶极性电荷结构的结论，利用加入了起放电参数化方案的WRF模式，模拟了广东在2017年5月8日发生的一次飑线过程，并对这次飑线过程中一个雷暴单体成熟期的电荷结构演变特征进行分析，通过分析动力、云水含量、各水成物粒子混合比及携带电荷情况，讨论了电荷结构的形成及演变机制。结果表明，成熟阶段的单体，电荷结构从三极性逐渐演变为偶极性。这是因为在成熟初期，霰粒子在有效液态水含量适中且温度较高的地方与冰晶/雪花粒子发生了非感应碰撞，因此底部霰粒子携带正电，雷暴云底部形成次正电荷区，电荷结构为三极性。而在成熟后期，由于丰富的云水含量，使冰粒子的凇附过程增强，霰不断增加，冰晶和雪花不断被消耗，温度较暖区域与霰共存的冰晶和雪花急剧减少，使得该区域大小冰粒子的非感应碰撞起电急剧减少，此处霰粒子不能再通过非感应碰撞获得正电荷，底部次正电荷区随之消失，雷暴云的电荷结构转变为偶极性。此结果和以往观测反推得到的结论不同，这表明，对南方雷暴电荷结构还需继续深入认识。
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| 关 键 词： | 广东雷暴 飑线 WRF模式 水成物粒子 电荷结构 |
| 收稿时间： | 2020-03-20 |
NUMERICAL SIMULATION OF CHARGE STRUCTURE EVOLUTION CHARACTERISTICS OF A THUNDERSTORM CELL AT MATURE STAGE DURING A SQUALL LINE EVENT IN GUANGDONG |
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| GAN Ming-jun,GUO Feng-xi,LI Qi,LIU Ze,ZHANG Kun,CAI Bin-bin.NUMERICAL SIMULATION OF CHARGE STRUCTURE EVOLUTION CHARACTERISTICS OF A THUNDERSTORM CELL AT MATURE STAGE DURING A SQUALL LINE EVENT IN GUANGDONG[J].Journal of Tropical Meteorology,2020,36(4):562-576. |
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| Authors: | GAN Ming-jun GUO Feng-xi LI Qi LIU Ze ZHANG Kun CAI Bin-bin |
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| Institution: | Key Laboratory of Meteorological Disaster, Ministry of Education/ Joint International Research Laboratory of Climate and Environment Change/ Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/ Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China |
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| Abstract: | In order to further confirm the conclusion that most thunderstorm clouds in Guangdong are dipole charge structures, the present study uses the WRF model that features charging and discharging parameterization to simulate a squall line event in Guangdong Province on May 8, 2017 and to analyze the evolution characteristics of the charge structure of mature thunderstorm cell during this squall line event and discuss the formation and evolution mechanism of the charge structure by analyzing the dynamics, cloud water content, mixing ratio and the charge carried of hydrometeors. The results show that the charge structure of mature thunderstorm cell changes from tripole polarity to dipole distribution. This is because at the initial stage of maturity, graupel particles have non-inductive collisions with ice crystal/snowflake particles in a place with moderate effective liquid water content and high temperature, so graupel particles at the bottom carry positive charge, and a secondary positive charge center is formed at the bottom of thunderstorm, and the charge structure becomes tripole polarity. However, in the late part of the mature stage, due to the abundant cloud water content, the rime attachment process of ice particles is enhanced, graupel is increasing, ice crystals and snowflakes are consumed, and the ice crystals and snowflakes coexisting with graupel are sharply reduced in the warmer area; therefore, the non-inductive collisions electrification of large and small ice particles in this area is sharply reduced. Graupel particles in the warmer area can no longer obtain positive charge through non-inductive collision, the lower positive charge center disappears, and the charge structure of thunderstorm cloud changes to dipole polarity. This result is different from the conclusion obtained from previous observations and it shows that the charge structure of thunderstorm in south China needs to be further studied. |
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| Keywords: | thunderstorm in Guangdong squall line WRF hydrometeor charge structure |
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