| 云南两次中尺度对流雷暴系统演变和地闪特征 |
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| 引用本文： | 张腾飞,尹丽云,张杰,谢屹然,朱莉.云南两次中尺度对流雷暴系统演变和地闪特征[J].应用气象学报,2013,24(2):207-218. |
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| 作者姓名： | 张腾飞 尹丽云 张杰 谢屹然 朱莉 |
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| 作者单位： | 1.云南省气象台，昆明 650034 |
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| 基金项目： | 国家自然科学基金项目（41265001），云南省科技计划项目（2009CA014） |
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| 摘 要： | 在利用NCEP/NCAR再分析资料诊断分析2010年9月21—23日中尺度对流雷暴系统形成的环流背景基础上，通过云南省闪电定位系统地闪监测资料和FY-2E卫星云图资料的同步叠加, 分析两个中尺度雷暴系统的演变和地闪特征。结果表明:台风凡亚比 (1011) 西行减弱的热带低压为中尺度对流雷暴系统提供有利的暖湿和抬升动力环流背景，促使中尺度弧状对流云带、中尺度雷暴云团和中尺度对流复合体生成和发展。雷暴云团结构和地闪活动空间分布不均匀并随时间变化，且正、负地闪频数与云顶亮温 (TBB) 相关，当TBB降低和等值线密度变大，雷暴云团发展，低TBB中心偏于云团的前部云区，负地闪频数剧增；当TBB达最低值时，雷暴云团成熟，负地闪频数达峰值，正地闪出现；当TBB升高且等值线密度变小时，雷暴云团减弱，低TBB中心靠近云团中心，负地闪频数迅速减小，正地闪频数达到峰值；密集的负地闪出现在雷暴云团前部大的TBB梯度区和TBB不大于-56℃的低值中心附近，正地闪分散在TBB不大于-56℃的低值中心附近，偏于负地闪区域后部发生。
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| 关 键 词： | 云南 中尺度对流雷暴系统 地闪特征 |
| 收稿时间： | 2012-05-12 |
Evolutions and Cloud-to-ground Lightning Features of Two Mesoscale Convective Thunder Storm Systems in Yunnan |
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| Zhang Tengfei,Yin Liyun,Zhang Jie,Xie Yiran and Zhu Li.Evolutions and Cloud-to-ground Lightning Features of Two Mesoscale Convective Thunder Storm Systems in Yunnan[J].Quarterly Journal of Applied Meteorology,2013,24(2):207-218. |
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| Authors: | Zhang Tengfei Yin Liyun Zhang Jie Xie Yiran and Zhu Li |
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| Institution: | 1.Yunnan Provincial Meteorological Observatory, Kunming 6500342.Yunnan Provincial Meteorological Information Center, Kunming 650034 |
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| Abstract: | The circulation background of mesoscale convective thunderstorm system is diagnostically analyzed from 21 September to 23 September in 2010 by NCEP/NCAR data, and the evolutions and cloud-to-ground lightning activity features of two mesoscale convective thunderstorm systems are analyzed by synchronous stack of lightning detection system observations and FY-2E satellite images. Results show that the advantageous circulation background conditions of high energy, high humidity, and lifting dynamism are also supplied for the mesoscale convective thunderstorm systems by the weakened thermal depression. Mesoscale arc convective cloud belts appears first, on which partial convective cloud clusters gradually develop to mesoscale storm cloud clusters and then run into mesoscale convective storm complexes moving to the west along the same route, leading to strong thunderstorm weather and frequent CG lightning activities on the way.The negative cloud-to-ground (negative CG) lightning is predominant compared to the positive cloud-to-ground (positive CG) lightning during the whole lifetime of a thunder cloud cluster. But not only the storm cloud cluster contracture and the CG lightning activity feature change with time, but also positive CG and negative CG lightning frequency is well related to the cloud top temperature, which is related to the three-negative-polar structure of thunder cloud over the lower latitude plateau of China. When the cloud top temperature TBB descends and TBB isoline density increases, the thunder cloud cluster develops gradually, the low TBB center locates to its foreside, and the negative CG lightning frequency leaps. When the TBB descends to the minimum, the thunder cloud cluster develops to the maturation, negative CG lightning frequency gets to an apex, and positive CG lightning begin to take place. When the TBB ascends and TBB isoline density decreases, the thunder cloud cluster weakens gradually, the low TBB center closes up its center, the negative CG lightning frequency decreases rapidly, and positive CG lightning frequency increases to the apex gradually. In the meantime when TBB of a thunder cloud cluster is lower, convective development is stronger and CG lightning activity is more furious.The storm cloud cluster contracture and the CG lightning spatial distribution are asymmetric. In its foreside TBB is lower and the TBB isoline density and grads are bigger than those in its rearward. Negative CG lightning mainly cluster in its foreside with big TBB grads and within the low center where TBB is no higher than-56℃, while sparse positive CG lightning usually disperse within the low center when TBB is no higher than-56℃, namely taking place in the rearward of dense negative CG lightning. The activity of positive CG and negative CG lightning are negatively correlated. Positive CG lightning hardly takes place during the negative CG rapid incremental phase, it usually begins during the negative CG lightning mild phase, and it increases when negative CG lightning weaken. So negative CG lightning is the result of storm cloud cluster development and positive CG lightning is the result of storm cloud cluster developing to mature. |
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| Keywords: | Yunnan meso scale convective storm system clound to ground lightning feature |
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