Lightning strikes to towers: An attempt to identify the effect of the channel resistance on wave interactions at the return-stroke front

2016 ◽  
Author(s):  
Alberto De Conti
Keyword(s):  
Wave Interactions ◽  
Return Stroke ◽  
Lightning Strikes ◽  
Channel Resistance

scholarly journals High-speed video observations on fork lightning events in Malaysia

2020 ◽  
Vol 19 (3) ◽  
pp. 1620
Author(s):  
Nor Asrina Binti Ramlee ◽  
N. A. Ahmad ◽  
Z. A. Baharudin ◽  
A. R. Mohamed
Keyword(s):  
High Speed ◽  
Temporal Analysis ◽  
Lightning Protection ◽  
Stroke Event ◽  
Time Duration ◽  
Return Stroke ◽  
Lightning Strikes ◽  
High Speed Video ◽  
Three Samples ◽  
Video Observations

Malaysia is one of the countries with the highest lightning strikes incidence in the world. Yet, Malaysians are still taking a proper lightning protection indifferent manner. This might be due to lack of knowledge on lightning characteristics in Malaysia. Therefore, this study presents an unusual lightning phenomenon with multiple grounding points that might cause a disastrous event, called fork lightning. Between November and December 2018, there were three different patterns of fork lightning mechanism successfully recorded by using high speed camera with 2800 frame per second. Temporal analysis of the lightning progress had been done on the samples based only on the camera records which then played back by using Wondershare Filmora video editor. These three samples of fork lightning images were acquired among 37 lightning events recorded in this study. The first sample of fork lightning fully established the forked branch 0.35 ms before the return stroke occurred. On the contrary, second fork lightning established its forked branch 0.35 ms after the return stroke. Both forked branches for third sample simultaneously fully established with the return stroke event. Obviously, these events had striking the ground in up to ten milliseconds of time duration. Thus, there is always a possibility that they might cause serious damage and should not be neglected in designing a lightning protection system.

Radiated Fields From Lightning Strikes to Tall Structures: Effect of Upward-Connecting Leader and Reflections at the Return Stroke Wavefront

2011 ◽  
Vol 53 (2) ◽  
pp. 437-445 ◽  
Author(s):  
A Mosaddeghi ◽  
F Rachidi ◽  
M Rubinstein ◽  
F Napolitano ◽  
D Pavanello ◽  
...  
Keyword(s):  
Return Stroke ◽  
Lightning Strikes ◽  
Tall Structures

scholarly journals Latitude and Topographical Dependence of Lightning Return Stroke Peak Current in Natural and Tower-Initiated Negative Ground Flashes

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 560
Author(s):  
Vernon Cooray ◽  
Marcos Rubinstein ◽  
Farhad Rachidi
Keyword(s):  
Experimental Data ◽  
Negative Charge ◽  
Geographical Region ◽  
Return Stroke ◽  
Peak Current ◽  
Tropical Regions ◽  
Lightning Strikes ◽  
Charge Center ◽  
Theoretical Predictions

Experimental data show that the peak currents of first and subsequent lightning return strokes in negative ground flashes increase with decreasing latitude. In this paper, the reason for this dependence of peak return stroke current on latitude is explained using the fact that the height of the charge centers increases with decreasing latitude. Results show that in tropical regions where the height to the negative charge center is about 8 km, the median values of the first and the subsequent return stroke peak currents are about 42 kA and 15 kA, respectively. If the height to the charge center is larger than 8 km, the peak currents will also become larger. For example, if the location of the charge center is increased to about 9 km, the median values of the first and subsequent return stroke peak currents will increase to about 45 kA and 16 kA respectively. The same reasoning shows that, even in the same geographical region, the peak return stroke current may decrease as the elevation of the ground where the lightning strikes take place increases. The results also indicate that the peak subsequent return stroke current in tower-initiated negative lightning flashes decreases as the height of the tower increases. These theoretical predictions are in general agreement with the available experimental data.

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