scholarly journals The Energy, Momentum, and Peak Power Radiated by Negative Lightning Return Strokes

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1288
Author(s):  
Vernon Cooray ◽  
Andre Lobato
Keyword(s):  
Radiation Field ◽  
Peak Power ◽  
Outer Space ◽  
Cylindrical Symmetry ◽  
Return Stroke ◽  
Zero Crossing ◽  
Radiation Fields ◽  
Radiated Energy ◽  
Crossing Time ◽  
Energy And Momentum

Electromagnetic radiation fields generated by return strokes transport both energy and momentum from the return stroke to outer space. The momentum transported by the radiation field has only a vertical or z component due to azimuthal symmetry (cylindrical symmetry) associated with a vertical return stroke. In this paper, the energy, momentum, and peak power radiated by return strokes as a function of the return stroke current, return stroke speed, and the zero-crossing time of the radiation fields are studied. The results obtained by numerical simulations for the energy, vertical momentum, and the peak power radiated by lightning return strokes (all parameters normalized by dividing them by the square of the radiation field peak at 100 km) are the following: A typical first return stroke generating a radiation field having a 50 μs zero-crossing time will dissipate field normalized energy of about (1.7–2.5) × 103 J/(V/m)2 and field-normalized vertical momentum of approximately (2.3–3.1) × 10−6 Kg m/s/(V/m)2. A radiation field with a zero-crossing time of 70 μs will dissipate about (2.6–3.4) × 103 J/(V/m)2 in field-normalized energy and (3.2–4.3) × 10−6 Kg m/s/(V/m)2 in field-normalized vertical momentum. The results show that, for a given peak radiation field, the radiated energy and momentum increase with increasing zero-crossing time of the radiation field. The normalized peak power generated by a first return stroke radiation field is about 1.2 × 108 W/(V/m)2 and the peak power is generated within about 5–6 μs from the beginning of the return stroke. Conversely, a typical subsequent return stroke generating a radiation field having a 40 μs zero-crossing time will dissipate field-normalized energy of about (6–9) × 102 J/(V/m)2 and field-normalized vertical momentum of approximately (7.5–11) × 10−7 Kg m/s/(V/m)2. The field-normalized peak power generated by a subsequent return stroke radiation field is about 1.26 × 108 W/(V/m)2 and the peak power is generated within about 0.7–0.8 μs from the beginning of the return stroke. In addition to these parameters, the possible upper bounds for the energy and momentum radiated by return strokes are also presented.

scholarly journals An analysis of manual and autoanalysis for submicrosecond parameters in the typical first lightning return stroke

2021 ◽  
Vol 23 (3) ◽  
pp. 1451
Author(s):  
Muhammad Akmal Bahari ◽  
Zikri Abadi Baharudin ◽  
Tole Sutikno ◽  
Ahmad Idil Abdul Rahman ◽  
Mohd Ariff Mat Hanafiah ◽  
...  
Keyword(s):  
Feature Extraction ◽  
Detection System ◽  
Programming Technique ◽  
Return Stroke ◽  
Zero Crossing ◽  
Manual Analysis ◽  
Lightning Detection ◽  
Crossing Time ◽  
Rising Time ◽  
Initial Peak

The mechanism on how lightning detection system (LDS) operated never been exposed by manufacturer since it was confidential. This scenario motivated the authors to explore the issue above by using MATLAB to develop autoanalysis software based on the feature extraction. This extraction is intended for recognizing the parameters in the first return stroke, and compare the measurement between the autoanalysis software and the manual analysis. This paper is a modification based on a previous work regarding autoanalysis of zero-crossing time and initial peak of return stroke using features extraction programming technique. Further, the parameter on rising time of initial peak is added in this autoanalysis programming technique. Finally, the manual analysis using WaveStudio (LeCroy product) of those two lightning parameters is compared with autoanalysis software. This study found that the autoanalysis produce similar result with the manual analysis, hence proved the reliability of this software.

Review and Evaluation of Characterization First Return Stroke in the Measured Lightning Electric Fields on Malaysia Data

2015 ◽  
Vol 793 ◽  
pp. 44-48
Author(s):  
S.N.M. Arshad ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Mahdi Izadi ◽  
A.M. Ariffen ◽  
M.N. Hamzah ◽  
...  
Keyword(s):  
Electric Fields ◽  
Rise Time ◽  
Statistical Correlation ◽  
Peak Time ◽  
Return Stroke ◽  
Zero Crossing ◽  
Time To Peak ◽  
Lightning Channel ◽  
Crossing Time

In this paper, the characterization of measured electric fields on first return stroke due to lightning channel was studied done. Likewise, previous studies on this case were discussed and reviewed accordingly. Furthermore, the first return stroke was analyzed done in detailed and was indicated on the real measured electric fields. Later the results were discussed appropriately. The behaviorsof first return stroke signal has beencharacterized from previous researchers. This study shows themeasured data in detailed, which include there are slow front time, first return stroke peak, time to peak, zero crossing time and 10% to 90% rise time. The characteristic of first return stroke signal data in Malaysia was compared with data gathered in Sweden. Moreover In addition, the statistical correlation between electric field zero times and corresponding rise times was also been studied.

scholarly journals Modified Transmission Line Model with a Current Attenuation Function Derived from the Lightning Radiation Field—MTLD Model

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 249
Author(s):  
Vernon Cooray ◽  
Marcos Rubinstein ◽  
Farhad Rachidi
Keyword(s):  
Radiation Field ◽  
Electromagnetic Fields ◽  
Input Parameter ◽  
Inverse Transformation ◽  
Attenuation Curve ◽  
Return Stroke ◽  
Zero Crossing ◽  
Base Current ◽  
Stroke Models ◽  
A Current

In return strokes, the parameters that can be measured are the channel base current and the return stroke speed. For this reason, many return stroke models have been developed with these two parameters, among others, as inputs. Here, we concentrate on the current propagation type engineering return stroke models where the return stroke is represented by a current pulse propagating upwards along the leader channel. In the current propagation type return stroke models, in addition to the channel base current and the return stroke speed, the way in which the return stroke current attenuates along the return stroke channel is specified as an input parameter. The goal of this paper is to show that, within the confines of current propagation type models, once the channel base current and the return stroke speed are known, the measured radiation field can be used to evaluate how the return stroke current attenuates along the channel. After giving the mathematics necessary for this inverse transformation, the procedure is illustrated by extracting the current attenuation curve from the typical wave shape of the return stroke current and from the distant radiation field of subsequent return strokes. The derived attenuation curve is used to evaluate both the subsequent and first return stroke electromagnetic fields at different distances. It is shown that all the experimentally observed features can be reproduced by the derived attenuation curve, except for the subsidiary peak and long zero-crossing times. In order to obtain electromagnetic fields of subsequent return strokes that are in agreement with measurements, one has to incorporate the current dispersion into the model. In the case of first return strokes, both current dispersion and reduction in return stroke speed with height are needed to obtain the desired features.

scholarly journals Comparing the Wave Characteristics of Breakdown Pulses of the Lightning Waveforms in the Himalayan Region

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Pitri Bhakta Adhikari ◽  
Aashutosh Adhikari
Keyword(s):  
Rise Time ◽  
Pulse Train ◽  
Amplitude Ratio ◽  
Pulse Amplitude ◽  
Himalayan Region ◽  
Time Interval ◽  
Return Stroke ◽  
Zero Crossing ◽  
Wave Characteristics ◽  
Crossing Time

We have analyzed the breakdown pulse train with or without the main event in this paper. Among the selected 81 flashes, 36 flashes are starting positively, and 45 are starting negatively. Also, 58 flashes contain positive pulses, and 67 flashes contain negative pulses, whereas 44 flashes contain both positive and negative pulses. Among these 81 flashes, 22 flashes follow the main events, and the rest are isolated events. In this study, we got the main duration of PB pulses as 1.94 ms and the time interval between the breakdown pulse and return stroke as 61.49 ms. On taking each pulse train, we found the rise time to be 2.6 μs, zero-crossing time 14.95 μs, and the time interval between pulses 199.3 μs. The largest pulse amplitude ratio in the preliminary breakdown pulse to the main event return stroke was 0.43.

scholarly journals Effects of Propagation of Narrow Bipolar Pulses, Generated by Compact Cloud Discharges, Over Finitely Conducting Ground

2018 ◽  
Author(s):  
Vernon Cooray ◽  
Mahendra Fernando ◽  
Lasitha Gunasekara ◽  
Sankha Nanayakkara
Keyword(s):  
Remote Sensing ◽  
Time Derivative ◽  
High Time Resolution ◽  
Full Width ◽  
Half Maximum ◽  
Zero Crossing ◽  
Radiation Fields ◽  
Temporal Features ◽  
Crossing Time ◽  
Propagation Effects

Propagation effects on the Narrow Bipolar Pulses (NBPs) or the radiation fields generated by compact cloud discharges as they propagate over finitely conducting ground are presented. The results are obtained using a sample of NBPs recorded with high time resolution from close thunderstorms in Sri Lanka. The results show that the peak amplitude and the temporal features such as the Full Width at Half Maximum (FWHM), zero crossing time and the time derivative of NBPs can be significantly distorted by propagation effects. For this reason the study of peak amplitudes and temporal features of NBPs and the remote sensing of current parameters of compact cloud discharges should be conducted using NBPs recorded under conditions where the propagation effects are minimal.

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

Characterization of interbedded thin beds using zero-crossing-time amplitude stratal slices

Geophysics ◽  
2015 ◽  
Vol 80 (5) ◽  
pp. N23-N35 ◽  
Author(s):  
Guofa Li ◽  
Mauricio D. Sacchi ◽  
Yajing Wang ◽  
Hao Zheng
Keyword(s):  
Zero Crossing ◽  
Crossing Time

scholarly journals Polarity Asymmetry in Lightning Return Stroke Speed Caused by the Momentum Associated with Radiation

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1642
Author(s):  
Vernon Cooray ◽  
Gerald Cooray ◽  
Marcos Rubinstein ◽  
Farhad Rachidi
Keyword(s):  
Radiation Field ◽  
Opposite Direction ◽  
Maximum Speed ◽  
Return Stroke ◽  
Positive Return

In positive lightning return strokes, the net momentum transported by the radiation field has the same direction as the momentum associated with electrons, whereas the momentum associated with electrons is in opposite direction to the momentum of radiation in negative return strokes. It is shown here that this polarity asymmetry could limit the maximum speed of positive return strokes with respect to the negative return strokes.

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