First versus subsequent return-stroke current and field peaks in negative cloud-to-ground lightning discharges

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.

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Charge analysis on lightning discharges to the ground in Chinese inland plateau (close to Tibet)

Annales Geophysicae ◽

10.1007/s00585-000-1340-z ◽

2000 ◽

Vol 18 (10) ◽

pp. 1340-1348 ◽

Cited By ~ 16

Author(s):

X. Qie ◽

Y. Yu ◽

X. Liu ◽

C. Guo ◽

D. Wang ◽

...

Keyword(s):

Negative Charge ◽

Atmospheric Electricity ◽

Tibet Plateau ◽

Return Stroke ◽

Convective Processes ◽

Long Duration ◽

Radar Echo ◽

Lightning Discharges ◽

Cloud To Ground Lightning ◽

Charge Analysis

Abstract. Since the summer of 1996, scientists from China and Japan have conducted a joint observation of natural cloud-to-ground lightning discharges in the Zhongchuan area that is located close to Qinghai-Xizang (Tibet) Plateau, China. It has been found that the long-duration of intracloud discharge processes, just before the first return stroke, lasted more than 120 ms for 85% of cloud-to-ground flashes in this area, with a mean duration of 189.7 ms and a maximum of 300 ms. We present the results of charge sources neutralized by four ground flashes and two intracloud discharge processes, just before the first return stroke, by using the data from a 5-site slow antenna network synchronized by GPS with 1 µs time resolution. The result shows that the altitudes of the neutralized negative charge for three negative ground flashes were between 2.7 to 5.4 km above the ground, while that of neutralized positive charges for one positive ground flash and one continuing current process were at about 2.0 km above the ground. The comparison with radar echo showed that the negative discharges initiated in the region greater than 20 dBZ or near the edge of the region with intense echoes greater than 40 dBZ, while positive discharge initiated in the weak echo region.Key words: Meterology and atmospheric dynamics (atmospheric electricity; convective processes; lightning)

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

International Journal of Integrated Engineering ◽

10.30880/ijie.2019.11.03.031 ◽

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

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Comprehensive Analysis of a Coast Thunderstorm That Produced a Sprite over the Bohai Sea

Atmosphere ◽

10.3390/atmos12060718 ◽

2021 ◽

Vol 12 (6) ◽

pp. 718

Author(s):

Cong Pan ◽

Jing Yang ◽

Kun Liu ◽

Yu Wang

Keyword(s):

Bohai Sea ◽

Mesoscale Convective System ◽

Convective System ◽

Return Stroke ◽

Absolute Value ◽

Transient Luminous Events ◽

Stratiform Region ◽

Before And After ◽

Mesoscale Convective ◽

Cloud To Ground Lightning

Sprites are transient luminous events (TLEs) that occur over thunderstorm clouds that represent the direct coupling relationship between the troposphere and the upper atmosphere. We report the evolution of a mesoscale convective system (MCS) that produced only one sprite event, and the characteristics of this thunderstorm and the related lightning activity are analyzed in detail. The results show that the parent flash of the sprite was positive cloud-to-ground lightning (+CG) with a single return stroke, which was located in the trailing stratiform region of the MCS with a radar reflectivity of 25 to 35 dBZ. The absolute value of the negative CG (−CG) peak current for half an hour before and after the occurrence of the sprite was less than 50 kA, which was not enough to produce the sprite. Sprites tend to be produced early in the maturity-to-dissipation stage of the MCS, with an increasing percentage of +CG to total CG (POP), indicating that the sprite production was the attenuation of the thunderstorm and the area of the stratiform region.

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Pulse trains that are characteristic of preliminary breakdown in cloud-to-ground lightning but are not followed by return stroke pulses

Journal of Geophysical Research Atmospheres ◽

10.1029/2007jd008489 ◽

2008 ◽

Vol 113 (D1) ◽

Cited By ~ 64

Author(s):

Amitabh Nag ◽

Vladimir A. Rakov

Keyword(s):

Return Stroke ◽

Pulse Trains ◽

Cloud To Ground Lightning

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on the prevention of lighting

Bulletin of the American Meteorological Society ◽

10.1175/1520-0477-50.7.514 ◽

1969 ◽

Vol 50 (7) ◽

pp. 514-521 ◽

Cited By ~ 2

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.

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Magnetic Field due to the Radiation of High Altitude Lightning

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.b1008.0982s1219 ◽

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.

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First ground-based observations of sprites over southern Africa

South African Journal of Science ◽

10.17159/sajs.2018/4272 ◽

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.

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