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Positive Charge Region in Lower Part of Thunderstorm and Preliminary Breakdown Process of Negative cloud-to-ground lightning

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Acta meteorologica Sinica 2009年第1期23卷 95-104页

作者：张义军孟青吕伟涛马明郑栋 Pau R.Krehbiel Laboratory of lightning Physics and Protection Engineering Chinese Academy of Meteorological Sciences State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences New Mexico Institute of Mining and Technology

A new lightning locating technology, called lightning Mapping Array （LMA）, has been developed. The system takes advantage of GPS technology to measure the times of arrival （TOA） of lightning impulsive very high frequency （VHF） radiation events at each remote location. The spatiotemporal development processes of lightning are described in three-dimension by measurement of the system with high time resolution （50 ns） and space precision （50-100 m）. The charge structures in thunderstorm and their relationship with lightning discharge processes are revealed. The temporal and spatial characteristics of preliminary breakdown process involved in negative cloud-to-ground （CG） lightning discharges are analyzed based on the data of lightning VHF radiation events. The effect of positive charge region in lower part of thunderstorm on the occurrence of negative CG lightning discharge is discussed. The results indicate that the preliminary breakdown process with longer duration in negative CG lightning discharges is an intracloud discharge process. It occurs between negative and positive charge regions located in middle and lower parts of thunderstorm respectively. It initiates from the negative charge region and propagates downward. After propagating into the positive charge region, the lightning channel develops horizontally. The characteristics of the preliminary breakdown process are consistent with that of intracloud lightning discharges. The stepped leaders are initiated by the K type breakdown which occurs in the last stage of the preliminary breakdown process and develops downward through the positive charge region. The existence of positive charge region in lower part of thunderstorm results in the occurrence of preliminary breakdown process with longer duration before the return stroke of negative CG lightning discharges.

关键词： cloud-to-ground lightning positive charge preliminary breakdown process

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Optical Observations on Propagation Characteristics of Leaders in cloud-to-ground lightning Flashes

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Acta meteorologica Sinica 2008年第1期22卷 66-77页

作者：吕伟涛张义军李俊郑栋董万胜陈绍东王飞 Laboratory of lightning Physics and Protection Engineering Chinese Academy of Meteorological Sciences

Using 2 high-speed cameras, we have recorded 14 negative cloud-to-ground （CG） lightning flashes, half of which are natural and the others are artificially triggered. The two-dimensional （2D） propagation speed of different type leaders and the luminosity of lightning channel are analyzed in detail. Bidirectional leader processes are observed during the initial processes of two altitude triggered negative lightning （ATNL） flashes. The analysis shows： the propagation speed of the upward positive leader （UPL） before the initiation of the downward negative leader （DNL） is at the order of 10^4-10^5 m s-1; the UPL can be intensified by the initiation and development of the DNL in the way that the luminosity is enhanced and the speed is sped up; after initiation, the DNL in one ATNL flash propagates downward three times intermittently with interval of about 1 ms, while that in the other ATNL flash propagates downward continuously with a speed at the order of 10^5 m s^-1. In the five classical triggered negative lightning （CTNL） flashes, the propagation speeds of the UPLs vary between 0.35×10^5 and 7.71×10^5 m s-1, and the variations of their luminosities and speeds are quite complex during the development processes. Among the four observed natural negative lightning flashes occurred on the land, three have only one return stoke （RS） each and all of their DNLs have many branches with an average speed at the order of 10^5 m s-l; while the another one has 13 RSs. In the CG flash with 13 RSs, the DNL before the first RS has no obvious branch below 1.4 km above the ground, and its speed ranges from 2.2×10^5 to 2.3×10^6 m s-1 between the heights of 0.7 and 1.4 km and exceeds 3.9×10^6 m s-1 below 0.7 km; preceding the 4th RS, an attempted leader is observed with a speed ranging from 1.1× 10^5 to 1.1×10^6 m s-1 between 0.8 and 1.5 km. As for the three observed natural negative lightning flashes occurred on the sea, each has only one RS, and each DNL preceding the RS has a few branc

关键词： cloud-to-ground lightning propagation speed of leader luminosity of lightning channel highspeed photography

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The Characteristics of cloud-to-ground lightning Activity with Severe Thunderstorm Wind in South and North China

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Atmospheric and Oceanic Science Letters 2014年第6期7卷 571-576页

作者： YANG Xin-Lin SUN Jian-Hua Chengdu University of Information Technology Key Laboratory of cloud-Precipitation Physics and Severe Storms Institute of Atmospheric PhysicsChinese Academy of Sciences Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science & Technology

The characteristics of cloud-to-ground(CG) lightning activity with severe thunderstorm wind(STW) in South and North China are analyzed using CG lightning data, radar data, and serious weather reports. The percentage of positive CG(PCG) flashes with STW in North China is larger than that in South China. STW takes place during the period when the total CG and PCG density is increasing fastest. STW also occurs close to the high-value center of CG and PCG density. In North China, the CG and PCG density in the grid of STW maximizes approximately 20 minutes after the STW occurs; while in South China, the PCG density and percentage of PCG in the grid of STW maximizes about 10 minutes before the occurrence of STW. The high-value centers of CG density and PCG density in North China move slightly faster than those in South China, which is opposite to the rate of increasing CG activity.

关键词： cloud-to-ground lightning severe thunderstorm wind severe convection

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Study on the Scope of Small Amplitude of cloud-to-ground lightning in lightning Weather Monitoring

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Meteorological and Environmental Research 2014年第3期5卷 7-10,15页

作者： Luan Jian Wang Xing Wang Peng Nie Yang Wang Yue Tan Wei Liaoning lightning Protection Technical Service Center Liaoning lightning Protection Engineering Co. Ltd.

Based on lightning location data in Chongqing region during 1999-2008,the frequency of lightning in various amplitude ranges and its annual variations were analyzed ***,with the aid of matlab mathematical software,the distribution of the lightning location data was fitted using logarithmic normal distribution *** results showed that after data of cloud-to-ground lightning with current amplitude from-5 to5 kA were deleted from lightning location data,the statistical characteristics of cloud-to-ground lightning could be reflected ***,lightning with current amplitude from-5 to 5 kA accounted for 1.05%（less than 2%）,which accorded with the detection principle of lightning position indicator（there existed error detection）.Therefore,cloud-to-ground lightning with current amplitude of-5-5 kA in lightning location data of Chongqing region was defined as small amplitude of cloud-to-ground lightning,which could provide scientific references for the processing of lightning location data in Chongqing region as well as analysis and quality control of lightning location data in other regions.

关键词： lightning location system Quality control Small amplitude cloud-to-ground lightning Logarithmic normal distribution China

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Characteristics of cloud-to-ground lightning during a Local Rainstorm in Meizhou City

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Meteorological and Environmental Research 2018年第2期9卷 4-7,11页

作者： Zhang Wenjie Guo Qing Zeng Huijuan Wu Yongbin Meizhou Meteorological Bureau of Guangdong Province Meizhou 514021 China Yunnan Meteorological Disaster Prevention Technology Center Kunming 650034 China

Based on cloud-to-ground lightning data of lightning location system,Doppler radar data,and precipitation data of regional automatic weather stations,the characteristics of cloud-to-ground lightning during a local rainstorm on June 4,2016 in Meizhou City were analyzed. The results showed that the spatial distribution of cloud-to-ground lightning from 14： 00 to 20： 00 on June 4,2016 in Meizhou City had obvious local characteristics,and the proportion of negative lightning was larger than that of positive lightning（ only 16. 8%）. The concentration period of positive lightning coincided with that of cloud-to-ground lightning. The peak of proportion of positive lightning lagged behind the peak of cloud-to-ground lightning,and appeared in the late period of thunderstorm disappearance. The dense area of cloud-to-ground lightning and the area with heavy rainfall coincided with the area with strong radar echoes. Doppler weather radar data had the feature of the headwind zone,strong combined reflectivity,vertical height of strong echoes,high echo top,and fast radial movement. The peak of cloud-to-ground lightning appeared one hour earlier than that of precipitation. There was no significant correlation between the frequency of cloud-to-ground lightning and precipitation. The peak of negative lightning corresponded to that of positive lightning,and cloud-to-ground lightning ended earlier than rainfall. After the peak of precipitation,convective system rapidly weakened and disappeared. Precipitation and the frequency of cloud-to-ground lightning fluctuated frequently during the whole process. The jumps and peaks of negative lightning were indicative of rainfall changes.

关键词： cloud-to-ground lightning Local rainstorm Meizhou City

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高建筑物上未连接上行先导的特征统计分析(英文)

高建筑物上未连接上行先导的特征统计分析(英文)

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强化科技基础推进气象现代化——第29届中国气象学会年会

作者：吕伟涛 Laboratory of lightning Physics and Protection Engineering Chinese Academy of Meteorological Sciences

The characteristics of 45 unconnected upward leaders(UULs) occurred in 19 downward negative flashes observed in Guangzhou during 2009-2011 are *** of the 45 UULs is an upward positive leader initiated by a downward negative stepped leader before a new strike point is *** each UUL,several parameters are determined when possible mainly by using high-speed images:inception height,inception time prior to return stroke(RS),horizontal distance between the strike point and the UUL’s inception point,two-dimensional(2D) distance between the nearest tip of the downward leader branches and the UUL’s inception point when the UUL is initiated,2D length,and 2D average propagation velocity,whose values range from 40 m to 503 m(number of samples:45),less than 0.1 ms to 1.32 ms(38),20 m to 1.3 km(38),99 m to 578 m(21),0.48 m to 399 m(45),and 5.79 to 33.8 × 10 4 m s-1(22),*** analysis of the UULs’ characteristics shows the following:(1) No UUL with an inception time prior to RS larger than 0.5 ms is initiated at a height lower than 300 m.(2) Those UULs with inception heights lower than 300 m seldom exhibit 2D lengths longer than 50 m,and most(22/27,81%) of them have 2D lengths of shorter than 20 ***(12/14,86%) of those UULs with 2D lengths longer than 50 m exhibit inception heights higher than 300 m.(3) Six of the 22 2D average propagation velocities are on the order of 10 4 m s-1 and 19(86%) of them are smaller than 2.0 × 10 5 m s-1.(4) Those UULs with inception heights lower than 300 m only can be initiated by those lightning flashes within approximately 600 m,while those with inception heights higher than 400 m can even be initiated by flashes over 1 km away.(5) The maximum distances for the downward leaders to attract the initiation of the UULs with inception heights from 100 m to 200,200 m to 300 m,and over 400 m are approximately 350 m,450 m,and 600 m,respectively.

关键词： cloud-to-ground lightning Unconnected upward leader Tall structure High-speed photography

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Temporal and Spatial Distribution of lightning Activity in Ulanqab City

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Meteorological and Environmental Research 2023年第1期14卷 60-62页

作者： Qiang MA Ulanqab Meteorological Bureau of Inner Mongolia Ulanqab 012000China

From January 2020 to December 2021,Ulanqab Meteorological Bureau of Inner Mongolia used VLF/LF lightning locator to carry out three-dimensional lightning monitoring in Ulanqab City,and compared with ADTD lightning location data in the same *** results show that both VLF/LF lightning locator and ADTD lightning locator had excellent monitoring ability for lightning during flood season in ***/LF lightning locator was slightly superior to ADTD lightning locator in observation accuracy,the observation ability of low-current cloud-to-ground lightning,intracloud lightning observation and so *** were obvious temporal and spatial characteristics of cloud-to-ground lightning during flood season in Ulanqab,and there was a certain correlation between the areas where lightning appeared frequently and surface *** lightning was mainly concentrated at a height of 1-7 *** cloud-to-ground lightning accounted for about 75%of total cloud-to-ground lightning,and negative intracloud lightning accounted for 39%of total intracloud lightning.

关键词： lightning location cloud-to-ground lightning Intracloud lightning Temporal and spatial distribution

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