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Zheng D.,Chinese Academy of Meteorological Sciences | Zhang Y.,Chinese Academy of Meteorological Sciences | Meng Q.,Chinese Academy of Meteorological Sciences | Dan J.,Conghua Meteorological Bureau
Advances in Atmospheric Sciences | Year: 2016

This study examined lightning activity and its relationship to precipitation and convective available potential energy (CAPE) in South China during 2001–12, based on data from the Guangdong Lightning Location System, the Tropical Rainfall Measuring Mission satellite, and the ERA-Interim dataset. Two areas of high lightning density are identified: one over the Pearl River Delta, and the other to the north of Leizhou Peninsula. Large peak-current cloud-to-ground (LPCCG) lightning (>75 kA) shows weaker land–offshore contrasts than total CG lightning, in which negative cloud-to-ground (NCG) lightning occurs more prominently than positive cloud-to-ground (PCG) lightning on land. While the frequency of total CG lightning shows a main peak in June and a second peak in August, the LPCCG lightning over land shows only a single peak in June. The ratio of positive LPCCG to total lightning is significantly greater during February–April than during other times of the year. Diurnally, CG lightning over land shows only one peak in the afternoon, whereas CG lightning offshore shows morning and afternoon peaks. The rain yield per flash is on the order of 107–108 kg per flash across the analysis region, and its spatial distribution is opposite to that of lightning density. Our data show that lightning activity over land is more sensitive than that over offshore waters to CAPE. The relationships between lightning activity and both precipitation and CAPE are associated with convection activity in the analysis region. © 2016, Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer-Verlag Berlin Heidelberg.


Zheng D.,Chinese Academy of Meteorological Sciences | Zhang Y.,Chinese Academy of Meteorological Sciences | Meng Q.,Chinese Academy of Meteorological Sciences | Dan J.,Conghua Meteorological Bureau
Journal of Climate | Year: 2016

The first climatological comparison of small-current cloud-to-ground (SCCG; peak current ≤50 kA) and large-current cloud-to-ground (LCCG; peak current > 50 kA, > 75 kA, and > 100 kA) lightning flashes is presented for southern China. The LCCG lightning exhibits an apparent preference to occur over the sea. The percentage of positive LCCG lightning during the nonrainy season was more than twice that during the rainy season, while the percentage of positive SCCG lightning showed small seasonal differences. Positive cloud-to-ground (PCG) lightning was more likely to feature a large peak current than was negative cloud-to-ground (NCG) lightning, especially during the nonrainy season and over land. Distinct geographical differences are found between SCCG and LCCG lightning densities and between their own positive and negative discharges. Furthermore, the percentages of positive lightning from LCCG and SCCG lightning exhibit distinctly different geographical and seasonal (rain and nonrainy season) distributions. The diurnal variations in SCCG and LCCG lightning are clearly different over the sea but similar over land. Diurnal variations in the percentage of positive lightning are functions of the peak current and underlying Earth's surface. In combination with the University of Utah precipitation feature (PF) dataset, it is revealed that thunderstorms with relatively weak convection and large precipitation areas are more likely to produce the LCCG lightning, and the positive LCCG lightning is well correlated with mesoscale convective systems in the spatial distribution during nonrainy season. © 2016 American Meteorological Society.


Zheng D.,Chinese Academy of Meteorological Sciences | Zheng D.,Guangzhou Field Experiment Site for Lightning Research and Testing | Zhang Y.,Chinese Academy of Meteorological Sciences | Zhang Y.,Guangzhou Field Experiment Site for Lightning Research and Testing | And 8 more authors.
Atmospheric Research | Year: 2013

The currents of 29 return strokes (RSs) involved in 10 classical triggered lightning flashes (TLFs) and an altitude TLF conducted in Guangdong, China from 2008 to 2011 are analyzed for the first time. They have relatively greater peak values (geometric mean (GM) of 16.07kA), average rate of rise between 10 and 90% (S10-90%, GM of 29.16kAμs-1), charge transfer within 1ms (Q1ms, GM of 1.36 C) and action integral within 1ms (AI1ms, GM of 5.39×103A2s), compared with those reported in other studies. The current peak value exhibits pronounced exponential relation with S10-90% (determination coefficient (R2)=0.43) and maximum rate of rise (R2=0.77), power relation with Q1ms (R2=0.89), and logarithmic relation with AI1ms (R2=0.93). Additionally, the discharges associated with the processes of initial-stage return strokes (ISRSs) involved in two altitude TLFs, with the peak currents of 10.09kA and 9.03kA, respectively, are investigated. Their peak, 10-90% risetime, average rate of rise between 10 and 90% and maximum rate of rise are comparable to those of the RSs. The chopped-shape pulses closely following the ISRSs and the pulses associated with the disintegration and reconnections of the wire's channel are also discussed. © 2012 Elsevier B.V.


Zhou W.,Chengdu University of Information Technology | Zhou W.,Chinese Academy of Meteorological Sciences | Zhou W.,Guangzhou Field Experiment Site for Lightning Research and Testing | Zhang Y.,Chinese Academy of Meteorological Sciences | And 9 more authors.
Wuli Xuebao/Acta Physica Sinica | Year: 2014

Occurrence regularity of chaotic pulse trains (CPT) discharge event in negative cloud-to-ground (CG) lightning during six thunderstorms are analyzed in this paper. Results show that CPT is a common phenomenon throughout the negative CG lightning discharge process, 243 times of CPT discharge events occurs during 323 negative CG lightning, a proportion reaching 75.2%. CPT in negative CG can occur before the first return stroke, between the strokes, and after the last stroke. The proportion of 66.7% of the total subsequent strokes is preceded by CPT, and CPT occurs after 11.5% of the total last strokes. It is also found that there are four distributions prior to subsequent strokes: single CPT-c (CPT connecting with subsequent strokes), single CPT-i (CPT occurring in an interval between CPT and return strokes), CPT-c and CPT-i occur concurrently, and several CPT-is appear concurrently. Single CPT-c is the most common, 39.4% of subsequent strokes are preceded by single CPT-c, and several CPTs are easier to occur before the first and second subsequent strokes, which are respectively the corresponding strokes 9.4% and 7.7% of the total number. With the increase of the order of subsequent stroke, there is a decreasing trend for the occurrence of CPT, and in addition to the previous two subsequent strokes, the number of CPT-c is obviously greater than CPT-i before the others. In addition, CPT-i and CPT-a both occur to add on the negative CG K-change, and some also correspond to the process of J-change in the slow electric field wave. © 2014 Chinese Physical Society.


Zheng D.,Chinese Academy of Meteorological Sciences | Zheng D.,Guangzhou Field Experiment Site for Lightning Research and Testing | Zhang Y.,Chinese Academy of Meteorological Sciences | Zhang Y.,Guangzhou Field Experiment Site for Lightning Research and Testing | And 10 more authors.
Acta Meteorologica Sinica | Year: 2012

This study investigates an abnormal artificially triggered lightning event that produced two positive upward propagations: one during the initial stage (i.e., the upward leader (UL)) and the other after a negative downward aborted leader (DAL). The triggered lightning was induced in a weak thunderstorm over the experiment site and did not produce a return stroke. All of the intra-cloud lightning around the experiment site produced positive changes in the electric field. The initial stage was a weak discharge process. A downward dart leader propagated along the channel produced by the first UL, ending at a height of approximately 453 m and forming a DAL. Under the influence of the DAL, the electric field at a point located 78 m from the rod experienced a steady reduction of about 6.8 kV m-1 over 5.24 ms prior to the initiation of a new upward channel (i.e., the second upward propagation (UP)). The second UP, which started approximately 4.1 ms after the termination of the DAL and propagated along the original channel, was triggered by the DAL and sustained for approximately 2.95 ms. Two distinct current pulses were superimposed on the current of the second UP. The first pulse, which was related to the sudden initiation of the second UP, was characterized by a more rapid increase and decrease and a larger peak value than the second pulse, which was related to the development of the second UP into the area affected by the DAL. The second UP contained both a similar-to-leader process and a following neutralization process. This study introduces a new type of triggering leader, in which a new upward discharge is triggered in an established channel by an aborted leader propagating along the same channel with opposite polarity and propagation direction. © The Chinese Meteorological Society and Springer-Verlag Berlin Heidelberg 2012.


Zhang Y.,Chinese Academy of Meteorological Sciences | Lu W.,Chinese Academy of Meteorological Sciences | Chen S.,Guangzhou Institute of Tropical and Marine Meteorology | Zheng D.,Chinese Academy of Meteorological Sciences | And 5 more authors.
Journal of Meteorological Research | Year: 2016

This paper reviews recent advances in understanding the physical processes of artificially triggered lightning and natural lightning as well as the progress in testing lightning protection technologies, based on a series of lightning field campaigns jointly conducted by the Chinese Academy of Meteorological Sciences and Guangdong Meteorological Bureau since 2006. During the decade-long series of lightning field experiments, the technology of rocket-wire artificially triggered lightning has been improved, and has successfully triggered 94 lightning flashes. Through direct lightning current waveform measurements, an average return stroke peak current of 16 kA was obtained. The phenomenon that the downward leader connects to the lateral surface of the upward leader in the attachment process was discovered, and the speed of the upward leader during the connection process being significantly greater than that of the downward leader was revealed. The characteristics of several return strokes in cloud-to-ground lighting have also been unveiled, and the mechanism causing damage to lightning protection devices (i.e., ground potential rise within the rated current) was established. The performance of three lightning monitoring systems in Guangdong Province has also been quantitatively assessed. © 2016, The Chinese Meteorological Society and Springer-Verlag Berlin Heidelberg.


Zheng D.,Chinese Academy of Meteorological Sciences | Zhang Y.,Chinese Academy of Meteorological Sciences | Lu W.,Chinese Academy of Meteorological Sciences | Dong W.,Chinese Academy of Meteorological Sciences | And 2 more authors.
2011 7th Asia-Pacific International Conference on Lightning, APL2011 | Year: 2011

The current measurements of 17 return strokes (RSs) produced by 6 classical triggered lightning flashes (TLFs) conducted in Guangdong, China from 2008 to 2010 were analyzed for the first time in this study. The geometric mean (GM) value of the peak value current (I Peak) is 16.59 kA, the half-peak width (t HPW) is 21.91 μs, the 10-90% risetime (t 10-90%) is 0.45 μs, the 10-90% average gradient (G 10-90%) is 29.61 kA μs -1, the maximum gradient (G Max) is 55.89 kA μs -1, the charge transfer in 1ms after the beginning of the return strokes (Q 1ms) is 1.61 C, and the action integral in 1ms after the beginning of the return strokes (AI 1ms) is 6.60×10 3 A 2 s. The RSs in GCOELD are, on average, stronger than those reported by other authors referenced in this study. The peak value current has a general good linear relation with G 10-90% (determination coefficient (R 2) = 0.64), a good linear relation with G Max (R 2=0.74), a strong power function relation with Q 1ms (R 2=0.89), and an excellent logarithmic function relation with AI 1ms (R 2=0.92). Additionally, the current of the initial-stage return stroke (ISRS) of an altitude TLF was analyzed and found to have small t HPW (2.12 μs), charge transfer (36.37 mC) and action integral (181.56 A 2 s), but was similar to other RSs for all other parameters. After the ISRS, a number of chopped-shape pulses, attributed to the back-and-forth reflections of the ISRS current, were recorded and analyzed for their characteristics. © 2011 IEEE.

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