scholarly journals Experimental simulation of a double return-stroke lightning flash by lasers

2002 ◽  
Vol 29 (23) ◽  
pp. 1-1-1-4 ◽  
Author(s):  
Hugo Sobral ◽  
Mayo Villagrán-Muniz ◽  
Rafael Navarro-González ◽  
Enrique Camps
Keyword(s):  
Experimental Simulation ◽  
Lightning Flash ◽  
Return Stroke

Investigation of Zero Crossing Detection for First Return Stroke in Negative Cloud-to-Ground Lightning Flash

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
Ahmad Idil Abd Rahman ◽  
◽  
Muhammad Akmal Bahari ◽  
Zikri Abadi Baharudin ◽  
◽  
...  
Keyword(s):  
Lightning Flash ◽  
Return Stroke ◽  
Zero Crossing ◽  
Cloud To Ground Lightning

scholarly journals Leader-chasing behavior in negative artificial triggered lightning flashes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fukun Wang ◽  
Jianguo Wang ◽  
Li Cai ◽  
Rui Su ◽  
Wenhan Ding ◽  
...  
Keyword(s):  
High Speed ◽  
The Other ◽  
Lightning Flash ◽  
High Speed Camera ◽  
Return Stroke ◽  
Catching Up ◽  
Special Cases ◽  
Triggered Lightning

AbstractTwo special cases of dart leader propagation were observed by the high-speed camera in the leader/return stroke sequences of a classical triggered lightning flash and an altitude-triggered lightning flash, respectively. Different from most of the subsequent return strokes preceded by only one leader, the return stroke in each case was preceded by two leaders occurring successively and competing in the same channel, which herein is named leader-chasing behavior. In one case, the polarity of the latter leader was opposite to that of the former leader and these two combined together to form a new leader, which shared the same polarity with the former leader. In the other case, the latter leader shared the same polarity with the former leader and disappeared after catching up with the former leader. The propagation of the former leader in this case seems not to be significantly influenced by the existence of the latter leader.

scholarly journals Evaluation of Horizontal Electric Field from the Lightning Channel by Electromagnetic Field Equations of Moving Charges

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Yunfeng Zhang ◽  
Erchun Zhang ◽  
Jialiang Gu
Keyword(s):  
Electromagnetic Field ◽  
Electric Field ◽  
Finite Conductivity ◽  
Lightning Flash ◽  
Horizontal Distance ◽  
Field Equations ◽  
Long Distance ◽  
Return Stroke ◽  
Lightning Channel ◽  
Soil Conductivity

The horizontal electric field from the lightning return-stroke channel is evaluated by the electromagnetic field equations of moving charges in this paper. When a lightning flash strikes the ground, the charges move upward the lightning channel at the return-stroke speed, thereby producing the electromagnetic fields. According to the electromagnetic field equations of moving charges, the detained charges, uniformly moving charges, and decelerating (or accelerating) charges in each segment of the channel generate electrostatic fields, velocity fields, and radiation fields, respectively. The horizontal component of the sum is the horizontal electric field over the perfectly conducting ground. For the real soil with finite conductivity, the Wait formula is used here for the evaluation of the horizontal electric field over the realistic soil. The proposed method can avoid the oscillation of the fields in the long distance by the FDTD method and the singularity problem of the integral equation by the Sommerfeld integral method. The influences of the return-stroke speed, distance, and soil conductivity on the horizontal electric field are also analyzed by the proposed method. The conclusions can be drawn that the horizontal electric field decreases with the increasing of the return-stroke speed; the negative offset increases with the increasing of horizontal distance and with the decreasing of the soil conductivity, thereby forming the bipolar waveform. These conclusions will be practically valuable for the protection of lightning-induced overvoltage on the transmission lines.

scholarly journals Time Domain Modelling of First Return Stroke of Lightning

2008 ◽  
Vol 2 (1) ◽  
pp. 261-270 ◽  
Author(s):  
Udaya Kumar ◽  
Rosy B. Raysaha ◽  
K.P. Dileep Kumar
Keyword(s):  
Electric Field ◽  
Field Evaluation ◽  
Simulation Method ◽  
Static Field ◽  
Linear Increase ◽  
Cloud Base ◽  
Open Boundary ◽  
Lightning Flash ◽  
Return Stroke ◽  
Stroke Evolution

The four most important factors that govern the return stroke evolution can be identified as: (i) electric field due to charge distributed along the channel, (ii) transient enhancement of conductance by several orders at the bridging regime (iii) the non-linear increase in channel conductance at the propagating current front and (iv) the associated dynamic electromagnetic field which support the evolution of current along the channel. For a more realistic modelling of the lightning return stroke, the present work attempts to consider these aspects in suitable manner. The charge simulation method is employed for evaluating the quasi-static field due to (i). For the dynamic field, the problem involves conduction along a thin structure with open boundary on one side. Further, in order to efficiently represent a vertically extended grounded strike object, as well as, channel of quite arbitrary geometry, boundary based approach is believed to be the ideal choice. Considering these, a time-dependent electric field integral equation (TD-EFIE) along with a sub-sectional collocation form of the method of moments (MoM) is chosen for the numerical field evaluation. The dynamic variation of conductance in the channel other than the bridging zone is modelled by a first order arc equation. For the bridging zone, arc equation which explicitly portray in some sense, accumulation of energy is considered. Accordingly, formulations given by Barannik, Popovic and Toepler were scrutinized for their suitability. After some preliminary simulation studies, a self contained model for the first return stoke of a lightning flash is presented. The stability of the model is verified by running the program for longer durations with different cloud base potentials and cloud base heights. Simulation results are in agreement with the field data on current and velocity decay rate for the first one kilometer height. Also, the relation between the charge density at channel tip and the return stroke current peak favorably compares with the literature.

Study on the Vertical Component of Lightning Electric Field during Monsoon Period in Malaysia

2014 ◽  
Vol 554 ◽  
pp. 623-627 ◽  
Author(s):  
Behnam Salimi ◽  
Zulkurnain Abdul-Malek ◽  
Kamyar Mehranzamir ◽  
Noor Azlinda Ahmad
Keyword(s):  
Pulse Train ◽  
Lightning Discharge ◽  
Vertical Component ◽  
Natural World ◽  
Statistical Analyses ◽  
Lightning Flash ◽  
Time Duration ◽  
Arithmetic Means ◽  
Return Stroke ◽  
Precise Knowledge

The most recognized and powerful demonstration of electrostatics in the natural world is a lightning discharge. The misoperation of several equipment and circuits would not only be caused by a direct contact with the lightning flash, but also by an indirect effect of a lightning channel. Appropriate information about lightning signature parameters can provide precise knowledge of lightning discharge that can be essential for the design of more improved detection and protective system. In this paper, the preliminary breakdown pulse train and the first return stroke of cloud to ground lightning discharge signatures observed in south of Malaysia are analyzed. Statistical analyses of the ratio between the maximum preliminary breakdown pulse trains amplitude and the first return stroke amplitude (BP/RS ratio), and the time duration between the high active part of the pulse train, and the return stroke (BP/RS separation) are presented. Observations on the statistical analyses show that about 94% of lightning signals have detectable breakdown pulses. The arithmetic means of BP/RS ratio and the BP/RS separation are 36.3% and 26.4ms, respectively.

Observation of Isolated Breakdown Lightning Flashes in a Tropical Region

2014 ◽  
Vol 554 ◽  
pp. 583-587 ◽  
Author(s):  
Kamyar Mehranzamir ◽  
Zulkurnain Abdul-Malek ◽  
Behnam Salimi ◽  
Noor Azlinda Ahmad
Keyword(s):  
Electric Discharge ◽  
Lightning Discharge ◽  
Tropical Region ◽  
Lightning Flash ◽  
High Current ◽  
Return Stroke ◽  
Tropical Regions ◽  
Cloud To Ground Lightning ◽  
Main Portion ◽  
The Impact

The impact of lightning on humans and its threats on life and structures have encouraged the scientists to pursue study in this field. Lightning flash is a high current electric discharge that can be classified into five categories which are intra-cloud discharges, cloud to cloud, cloud to air, ground to cloud and cloud to ground discharges. Intra-cloud discharges have the main portion of the lightning flashes. The most damages and disturbances of lightning flashes are due to cloud to ground and ground to cloud flashes. The discharge phenomenon has various behaviors even in the same thunderstorm. The cloud to ground lightning discharge starts with preliminary breakdown pulses followed by leaders which cause return strokes. The subsequent strokes happen after the first return stroke in a typical lightning flash, but in few flashes the discharges do not lead to any subsequent strokes. This research investigates on these types of flashes which are called isolated breakdown lightning flashes, in Malaysia. The isolated breakdown flashes have rarely been seen in tropical regions compared with temperate areas. Among 150 selected waveforms on 9thMay 2013 in our measurement station, only 10 isolated lightning flashes were observed in our dataset, which make up less than 7% of total flashes in one thunderstorm.

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