| 两种类型M分量物理特征和机制对比 |
| |
| 引用本文： | 谢盟,张阳,张义军,吕伟涛,郑栋.两种类型M分量物理特征和机制对比[J].应用气象学报,2015,26(4):451-459. |
| |
| 作者姓名： | 谢盟 张阳 张义军 吕伟涛 郑栋 |
| |
| 作者单位： | 1.中国气象科学研究院灾害天气国家重点实验室/雷电物理和防护工程实验室，北京 100081 |
| |
| 基金项目： | 国家自然科学基金项目（41205002,41030960），中国气象科学研究院基本科研业务费专项（2012Y006），科技部科研院所技术开发专项（2011EG137226） |
| |
| 摘 要： | 综合分析人工触发闪电通道底部的电流数据和电场变化数据，获得对M分量的新认识。M分量的幅值、上升时间、半峰值宽度、转移电荷量的几何平均值分别为301 A，341 μs，662 μs，0.207 C。但发现有两种类型的M分量，其统计特征和分布特征均体现了较大差别。第1类M分量幅度较小，半峰值宽度较大，上升时间较长；第2类M分量则幅度较大，半峰值宽度较小，上升时间较短，两类M分量和回击的时间间隔有较大差异。采用双波放电模型，通过设定不同入射电流波速度和反射电流波速度，对两类M分量进行从电流到电场的反演。结果表明:当模拟电场和测量电场比较一致时，第1类M分量的入射速度和反射速度的比值大于第2类M分量，即两类M分量的放电机制具有一定差异。
|
| 关 键 词： | 触发闪电 M分量 分类 物理机制 |
| 收稿时间： | 2014-11-24 |
| 修稿时间： | 2/9/2015 12:00:00 AM |
Comparative Analysis on Characteristics and Mechanism for Two Types of M component in Triggered Lightning |
| |
| Affiliation: | 1.Laboratory of Lightning Physics and Protection Engineering, State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 1000812.Chengdu University of Information Technology, Chengdu 610225 |
| |
| Abstract: | Parameters such as amplitude, rise time, half-peak width and charge transfer is obtained by analyzing channel base current data from triggered lightning, which is acquired by GCOELD (Guangdong Comprehensive Observation Experiment of Lightning Discharge) during 2008 and 2013. Geometric mean value of amplitude, rise time, half-peak width and charge transfer from 31 samples are 301 A, 341 μs, 662 μs and 0.207 C, among which geometric mean value of amplitude is close to the result from Shandong Articicially Triggering Lightning Experiment, while rise time and half-peak width are close to results in Florida. From the histogram for parameter distribution, M-component is mostly within 400 A, the rise time is lower than 400 μs, the half-peak width is less than 1 ms, and the charge transfer is from 0.1 C to 0.3 C. Whereas, histogram of amplitude, rise time, half-peak width and charge transfer indicates portion of M-component has unusual characteristics. Combined with previous research, it's concluded that M-component can be divided into two types, by amplitude lower/higher than 1 kA. Geometric mean value of amplitude, rise time, half-peak width and charge transfer is analyzed, respectively. Two types of M-component show obvious differences, for instance, the amplitude of Type 2 M-component is almost 10 times the value of Type 1 M-component, while the rise time and half-peak width is approximately quarter of the corresponding parameter for Type 1. In general, Type 2 M-component has higher amplitude, shorter rise time and narrower half-peak width than Type 1. The relationship between M amplitude and the lag between return stroke and M-component for Type 1 and Type 2 are compared, and lags of Type 2 M-components are shorter than 50 ms, shorter than lags of Type 1 M-components as a whole. It possibly indicates that the lower the amplitude of M-component is, the longer the lag is. With M-component two-wave model, the electric field are calculated. By configuring incident wave velocity and reflected wave velocity to various values, it's found that the result is consistent with measured electric field, but the incident velocity is always smaller than reflected velocity for both Type 1 and Type 2. The ratio between incident wave velocity and reflected wave velocity for Type 1 is larger than that of Type 2. Based on analysis for M-component characteristics and M-component classification, two types of M-component may correspond with streamer occurred by breakdown in channel branch into main channel and breakdown within part of the lightning channel, indicating Type 1 M-component has some differences with Type 2 M-component in mechanism. |
| |
| Keywords: | artificial triggered lightning M component classification physical mechanism |
|
| 点击此处可从《应用气象学报》浏览原始摘要信息 |
|
点击此处可从《应用气象学报》下载全文 |
|
