Jennings, S. G.; Latham, J. (1972). "The charging of water drops falling and colliding in an electric field". Archiv für Meteorologie, Geophysik und Bioklimatologie, Serie A. Springer Science and Business Media LLC. 21 (2–3): 299–306. Bibcode: 1972AMGBA..21..299J. doi: 10.1007/bf02247978. S2CID 118661076. Griffiths, R. F.; Phelps, C. T. (1976). "A model for lightning initiation arising from positive corona streamer development". Journal of Geophysical Research. 81 (21): 3671–3676. Bibcode: 1976JGR....81.3671G. doi: 10.1029/JC081i021p03671. A number of observations by space-based telescopes have revealed even higher energy gamma ray emissions, the so-called terrestrial gamma-ray flashes (TGFs). These observations pose a challenge to current theories of lightning, especially with the recent discovery of the clear signatures of antimatter produced in lightning. [118] Recent research has shown that secondary species, produced by these TGFs, such as electrons, positrons, neutrons or protons, can gain energies of up to several tens of MeV. [119] [120] Ozone and nitrogen oxides

Small, short duration sparks, recently documented near newly extruded magma, attest to the material being highly charged prior to even entering the atmosphere. [124] Colvin, J. D.; Mitchell, C. K.; Greig, J. R.; Murphy, D. P.; Pechacek, R. E.; Raleigh, M. (1987). "An empirical study of the nuclear explosion-induced lightning seen on IVY-MIKE". Journal of Geophysical Research. 92 (D5): 5696–5712. Bibcode: 1987JGR....92.5696C. doi: 10.1029/JD092iD05p05696.

Bead Lightning is the name given to the decaying stage of a lightning channel, which cools after a return stroke, and its luminosity breaks up into segments. It describes a stage of a normal lightning discharge rather than a type of lightning. Intense forest fires, such as those seen in the 2019–20 Australian bushfire season, can create their own weather systems that can produce lightning and other weather phenomena. [126] Intense heat from a fire causes air to rapidly rise within the smoke plume, causing the formation of pyrocumulonimbus clouds. Cooler air is drawn in by this turbulent, rising air, helping to cool the plume. The rising plume is further cooled by the lower atmospheric pressure at high altitude, allowing the moisture in it to condense into cloud. Pyrocumulonimbus clouds form in an unstable atmosphere. These weather systems can produce dry lightning, fire tornadoes, intense winds, and dirty hail. [126] Extraterrestrial The result is that the upper part of the thunderstorm cloud becomes positively charged while the middle to lower part of the thunderstorm cloud becomes negatively charged. [15] Minin, V. F.; Baibulatov, F. Kh. (1969). "On the nature of beaded lightning". Dokl. Akad. Nauk SSSR. 188 (4): 795–798.

R. I. Albrecht; S. J. Goodman; W. A. Petersen; D. E. Buechler; E. C. Bruning; R. J. Blakeslee; H. J. Christian. "The 13 years of TRMM Lightning Imaging Sensor: From individual flash characteristics to decadal tendencies" (PDF). NASA Technical Reports Server . Retrieved November 23, 2022. Anonymous (March 27, 2020). "Q&A: Monitoring Volcanic Eruptions Using Lightning". Physics. 13: 44. Bibcode: 2020PhyOJ..13...44.. doi: 10.1103/Physics.13.44. S2CID 242761615. General considerations Four-second video of a lightning strike, Island in the Sky, Canyonlands National Park, Utah, United States. Maggio, Christopher R.; Marshall, Thomas C.; Stolzenburg, Maribeth (2009). "Estimations of charge transferred and energy released by lightning flashes in short bursts". Journal of Geophysical Research: Atmospheres. 114 (D14): D14203. Bibcode: 2009JGRD..11414203M. doi: 10.1029/2008JD011506. Füllekrug, Martin; Mareev, Eugene A.; Rycroft, Michael J. (May 1, 2006). Sprites, Elves and Intense Lightning Discharges. Springer Science & Business Media. Bibcode: 2006seil.book.....F. ISBN 9781402046285. Archived from the original on November 4, 2017.

Airplane contrails have also been observed to influence lightning to a small degree. The water vapor-dense contrails of airplanes may provide a lower resistance pathway through the atmosphere having some influence upon the establishment of an ionic pathway for a lightning flash to follow. [131] Mazur, Vladislav (November 1982). "Associated lightning discharges". Geophysical Research Letters. 9 (11): 1227–1230. Bibcode: 1982GeoRL...9.1227M. doi: 10.1029/GL009i011p01227. Three primary types of lightning are defined by the "starting" and "ending" points of a flash channel. Aplin, K. L.; Harrison, R. G. (September 3, 2013). "Lord Kelvin's atmospheric electricity measurements". History of Geo- and Space Sciences. 4 (2): 83–95. arXiv: 1305.5347. Bibcode: 2013HGSS....4...83A. doi: 10.5194/hgss-4-83-2013. S2CID 9783512.

Cloud-to-cloud (CC) or inter-cloud lightning starts and ends between two different "functional" thundercloud units. In general, CG lightning flashes account for only 25% of all total lightning flashes worldwide. Since the base of a thunderstorm is usually negatively charged, this is where most CG lightning originates. This region is typically at the elevation where freezing occurs within the cloud. Freezing, combined with collisions between ice and water, appears to be a critical part of the initial charge development and separation process. During wind-driven collisions, ice crystals tend to develop a positive charge, while a heavier, slushy mixture of ice and water (called graupel) develops a negative charge. Updrafts within a storm cloud separate the lighter ice crystals from the heavier graupel, causing the top region of the cloud to accumulate a positive space charge while the lower level accumulates a negative space charge. Despite the popular misconception that these [ clarification needed] are positive lightning strikes due to them seemingly originating from the positive charge region, observations have shown that these are in fact negative flashes. They begin as IC flashes within the cloud, the negative leader then exits the cloud from the positive charge region before propagating through clear air and striking the ground some distance away. [79] [80]The overall discharge, termed a flash, is composed of a number of processes such as preliminary breakdown, stepped leaders, connecting leaders, return strokes, dart leaders, and subsequent return strokes. [71] The conductivity of the electrical ground, be it soil, fresh water, or salt water, may affect the lightning discharge rate and thus visible characteristics. [72] Positive and negative lightning

The upward motions within the storm and winds at higher levels in the atmosphere tend to cause the small ice crystals (and positive charge) in the upper part of the thunderstorm cloud to spread out horizontally some distance from the thunderstorm cloud base. This part of the thunderstorm cloud is called the anvil. While this is the main charging process for the thunderstorm cloud, some of these charges can be redistributed by air movements within the storm (updrafts and downdrafts). In addition, there is a small but important positive charge buildup near the bottom of the thunderstorm cloud due to the precipitation and warmer temperatures. [15] Upward lightning or ground-to-cloud lightning is a lightning flash which originates from the top of a grounded object and propagates upward from this point. This type of lightning can be triggered by a preceding lightning flash, or it may initiate entirely on its own. The former is generally found in regions where spider lightning occurs, and may involve multiple grounded objects simultaneously. [105] The latter usually occurs during the cold season and may be the dominant lightning type in thundersnow events. [106] Yair, Yoav; Aviv, Reuven; Ravid, Gilad; Yaniv, Roy; Ziv, Baruch; Price, Colin (2006). "Evidence for synchronicity of lightning activity in networks of spatially remote thunderstorms". Journal of Atmospheric and Solar-Terrestrial Physics. 68 (12): 1401–1415. Bibcode: 2006JASTP..68.1401Y. doi: 10.1016/j.jastp.2006.05.012. U.A.Bakshi; M.V.Bakshi (January 1, 2009). Power System – II. Technical Publications. p.12. ISBN 978-81-8431-536-3. Archived from the original on March 12, 2017.

4. Helicopters cause lightning

Uman, M. A. (2001). The lightning discharge. Courier Corporation. ISBN 9780486151984 . Retrieved September 1, 2020. Volcanic activity produces lightning-friendly conditions in multiple ways. The enormous quantity of pulverized material and gases explosively ejected into the atmosphere creates a dense plume of particles. The ash density and constant motion within the volcanic plume produces charge by frictional interactions (triboelectrification), resulting in very powerful and very frequent flashes as the cloud attempts to neutralize itself. Due to the extensive solid material (ash) content, unlike the water rich charge generating zones of a normal thundercloud, it is often called a dirty thunderstorm. Starting in 2016, the National Oceanic and Atmospheric Administration launched Geostationary Operational Environmental Satellite–R Series (GOES-R) weather satellites outfitted with Geostationary Lightning Mapper (GLM) instruments which are near-infrared optical transient detectors that can detect the momentary changes in an optical scene, indicating the presence of lightning. [148] [149] The lighting detection data can be converted into a real-time map of lightning activity across the Western Hemisphere; this mapping technique has been implemented by the United States National Weather Service. [150] Anvil crawler lightning, sometimes called spider lightning, is created when leaders propagate through horizontally-extensive charge regions in mature thunderstorms, usually the stratiform regions of mesoscale convective systems. These discharges usually begin as IC discharges originating within the convective region; the negative leader end then propagates well into the aforementioned charge regions in the stratiform area. If the leader becomes too long, it may separate into multiple bidirectional leaders. When this happens, the positive end of the separated leader may strike the ground as a positive CG flash or crawl on the underside of the cloud, creating a spectacular display of lightning crawling across the sky. Ground flashes produced in this manner tend to transfer high amounts of charge, and this can trigger upward lightning flashes and upper-atmospheric lightning. [67]