Characterization of positive cloud-to-ground Lightning Discharges

2010 ◽  
Author(s):  
Amitabh Nag ◽  
Vladimir A. Rakov ◽  
Dimitris Tsalikis ◽  
John A. Cramer
Keyword(s):  
Lightning Discharges ◽  
Cloud To Ground Lightning

scholarly journals on the prevention of lighting

1969 ◽  
Vol 50 (7) ◽  
pp. 514-521 ◽  
Author(s):  
C. D. Stow
Keyword(s):  
United States ◽  
Forest Fires ◽  
Western United States ◽  
Agricultural Crops ◽  
Loss Of Life ◽  
The World ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning ◽  
Recreational Resources

The destructive nature of cloud-to-ground lightning strokes is well known. Loss of life and damage to buildings and other man-made structures may to a large extent be prevented by the judicial use of lightning conductors and screens but no comparable protection may be offered to expanses of agricultural crops or forests. According to Fuquay (1967) lightning is the greatest single cause of forest fires in the western United States: during the period 1946–1962, 140,000 such fires occurred causing severe losses of timber, wildlife, watershed, and recreational resources. Comparable losses occur regularly in other parts of the world. The only solution is the suppression or modification of cloud-to-ground lightning discharges. Methods of suppression are described, some of which may turn out to be practical ways of achieving this aim.

scholarly journals Magnetic Field due to the Radiation of High Altitude Lightning

2020 ◽  
Vol 8 (2S12) ◽  
pp. 49-50
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Radiation ◽  
High Altitude ◽  
Low Frequency ◽  
Frequency Region ◽  
Middle Region ◽  
Very Low Frequency ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning ◽  
Frequency Radiation

High altitude optical discharges generated by extreme cloud-to-ground lightning strokes, which occur in the middle region of the atmosphere known as sprites. Streamer formation in sprites has been well stated to be existing by several previous workers. These streamers are not only responsible for the initiation of sprites but also they are composed of these streamers. It causes the production of electromagnetic radiation upto or below the ELF (very low frequency) region which have been reported earlier through various research theories. Thus, we are reporting out for the formulation of the model by using an earlier model used to estimate higher frequency radiation from cloud and ground lightning discharges through these positive corona streamers. Taking it into account, other terms like radiation magnetic field has been evaluated with the studied observations.

scholarly journals First ground-based observations of sprites over southern Africa

2018 ◽  
Vol 114 (9/10) ◽  
Author(s):  
Stanislaus Nnadih ◽  
Mike Kosch ◽  
Peter Martinez ◽  
Jozsef Bor
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Dielectric Breakdown ◽  
Electrical Discharges ◽  
Lightning Strikes ◽  
The World ◽  
Lightning Discharges ◽  
Northern Cape ◽  
Cloud To Ground Lightning ◽  
Peak Value

Sprites are the optical signatures of electrical discharges in the mesosphere triggered by large lightning strikes associated with thunderstorms. Since their discovery in the late 1980s, sprites have been observed extensively around the world, although very few observations of sprites from Africa have been documented in the literature. In this paper, we report the first ground-based recorded observations of sprites from South Africa. In 2 out of the 22 nights of observations (11 January and 2 February 2016), about 100 sprite elements were recorded from Sutherland in the Northern Cape, comprising different morphologies (carrot (55%), carrot/column (11%), unclassified (21%), column (13%)). The sprites were triggered by positive cloud-to-ground lightning strikes, which had an average peak value of ~74 kA and were observed at distances from ~400 km to 800 km. The estimated charge moment change of the lightning discharges associated with these events was in agreement with the threshold for dielectric breakdown of the mesosphere and correlates well with the observed sprite brightness.

A Review of Positive and Bipolar Lightning Discharges

2003 ◽  
Vol 84 (6) ◽  
pp. 767-776 ◽  
Author(s):  
V. A. Rakov
Keyword(s):  
Forest Fires ◽  
Return Stroke ◽  
Winter Storms ◽  
Convective Systems ◽  
Lightning Channel ◽  
Different Types ◽  
Mesoscale Convective ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning ◽  
Positive Return

Characteristics of lightning discharges that transport either positive charge or both positive and negative charges to the ground are reviewed. These are termed positive and bipolar lightning discharges, respectively. Different types of positive and bipolar lightning are discussed. Although positive lightning discharges account for 10% or less of global cloud-to-ground lightning activity, there are five situations that appear to be conducive to the more frequent occurrence of positive lightning. These situations include 1) the dissipating stage of an individual thunderstorm, 2) winter thunderstorms, 3) trailing stratiform regions of mesoscale convective systems, 4) some severe storms, and 5) thunderclouds formed over forest fires or contaminated by smoke. The highest directly measured lightning currents (near 300 kA) and the largest charge transfers (hundreds of coulombs or more) are thought to be associated with positive lightning. Two types of impulsive positive current waveforms have been observed. One type is characterized by rise times of the order of 10 μs, comparable to those for first strokes in negative lightning, and the other type is characterized by considerably longer rise times, up to hundreds of microseconds. The latter waveforms are apparently associated with very long, 1–2 km, upward negative connecting leaders. The positive return-stroke speed is of the order of 108 m s−1. Positive flashes are usually composed of a single stroke. Positive return strokes often appear to be preceded by significant in-cloud discharge activity, then followed by continuing currents, and involve long horizontal channels. In contrast to negative leaders, which are always optically stepped when they propagate in virgin air, positive leaders seem to be able to move either continuously or in a stepped fashion. The reported percentage of bipolar flashes in summer storms ranges from 6% to 14% and from 5% to 33% in winter storms. Bipolar lightning discharges are usually initiated by upward leaders from tall objects. It appears that positive and negative charge sources in the cloud are tapped by different upward branches of the bipolar-lightning channel.

Spatiotemporal characteristics of positive cloud-to-ground lightning discharges and bidirectional leader of the lightning

2006 ◽  
Vol 49 (2) ◽  
pp. 212-224 ◽  
Author(s):  
Yijun Zhang ◽  
Qing Meng ◽  
Krehbiel Paul ◽  
Xinsheng Liu ◽  
Muhong Yan ◽  
...  
Keyword(s):  
Spatiotemporal Characteristics ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning

scholarly journals Relativistic electron beams above thunderclouds

2011 ◽  
Vol 11 (5) ◽  
pp. 15551-15572
Author(s):  
M. Füllekrug ◽  
R. Roussel-Dupré ◽  
E. M. D. Symbalisty ◽  
J. J. Colman ◽  
O. Chanrion ◽  
...  
Keyword(s):  
Electron Beam ◽  
Relativistic Electron ◽  
Electron Beams ◽  
Low Frequency ◽  
Electric Circuit ◽  
Total Charge ◽  
Relativistic Electron Beams ◽  
Radio Signals ◽  
Lightning Discharges ◽  
Cloud To Ground Lightning

Abstract. Non-luminous relativistic electron beams above thunderclouds are detected by radio remote sensing with low frequency radio signals from 40–400 kHz. The electron beams occur 2–9 ms after positive cloud-to-ground lightning discharges at heights between 22–72 km above thunderclouds. The positive lightning discharges also cause sprites which occur either above or before the electron beam. One electron beam was detected without any luminous sprite occurrence which suggests that electron beams may also occur independently. Numerical simulations show that the beamed electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of 7 MeV to transport a total charge of 10 mC upwards. The impulsive current associated with relativistic electron beams above thunderclouds is directed downwards and needs to be considered as a novel element of the global atmospheric electric circuit.

Long-Term Spatial–Temporal Characterization of Cloud-to-Ground Lightning in the Metropolitan Region of Rio de Janeiro

2019 ◽  
Vol 176 (11) ◽  
pp. 5161-5175 ◽  
Author(s):  
Tales Bernardes Paulucci ◽  
Gutemberg Borges França ◽  
Renata Libonati ◽  
Alexandre M. Ramos
Keyword(s):  
Rio De Janeiro ◽  
Metropolitan Region ◽  
Cloud To Ground Lightning
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