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Encyclopedia > Lightning
Lightning over Oradea in Romania
Lightning over Oradea in Romania
Lightning over Zwickau in Germany
Lightning over Zwickau in Germany
Lightning over Ryman town. Northern Poland.
Lightning over Ryman town. Northern Poland.

Lightning is an atmospheric discharge of electricity, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms.[1] The leader of a bolt of lightning can travel at speeds of 60,000 m/s, and can reach temperatures approaching 30,000 °C (54,000 °F), hot enough to fuse soil or sand into glass channels.[2][3] There are over 16 million lightning storms every year.[1] Not to be confused with lightning. ... Lightning is a highly visible form of energy transfer. ... Lightning Lightning may refer to the following: in meteorology, lightning, the natural electrical phenomenon in slang, white lightning (a. ... Image File history File linksMetadata Download high resolution version (2048x3072, 3589 KB) This is a rotated version of Lightning over Oradea Romania. ... Image File history File linksMetadata Download high resolution version (2048x3072, 3589 KB) This is a rotated version of Lightning over Oradea Romania. ... Location of Oradea Coordinates: , Country County Status County capital Government  - Mayor Petru Filip (Democratic Party) Area  - County capital 111. ... Image File history File links Download high resolution version (2000x1130, 286 KB) Cloud to cloud lightning This image shows a cloud to cloud lightning in a very stormy and rainy night. ... Image File history File links Download high resolution version (2000x1130, 286 KB) Cloud to cloud lightning This image shows a cloud to cloud lightning in a very stormy and rainy night. ... Zwickau is a city of Germany, in the Bundesland Saxony (Sachsen), situated in a valley at the foot of the Erzgebirge, on the left bank of the Zwickauer Mulde, 130 km (82 miles) southwest of Dresden, south of Leipzig and south west of Chemnitz. ... Air redirects here. ... Electricity (from New Latin Ä“lectricus, amberlike) is a general term for a variety of phenomena resulting from the presence and flow of electric charge. ... A shelf cloud associated with a heavy or severe thunderstorm over Enschede, The Netherlands. ... Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ... “Sandstorm” redirects here. ... Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector), defined by distance in metres divided by time in seconds. ... For other uses, see Temperature (disambiguation). ... For other uses, see Celsius (disambiguation). ... For other uses, see Fahrenheit (disambiguation). ... fulgurite Fulgurites (from the Latin fulgur meaning thunderbolt) are natural hollow carrot-shaped glass tubes formed in quartzose sand or soil by lightning strikes. ... A shelf cloud associated with a heavy or severe thunderstorm over Enschede, The Netherlands. ...


Lightning can also occur within the ash clouds from volcanic eruptions, or can be caused by violent forest fires which generate sufficient dust to create a static charge.[1][4] Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ... For other uses, see Wildfire (disambiguation). ... This box:      Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. ...


How lightning initially forms is still a matter of debate:[5] Scientists have studied root causes ranging from atmospheric perturbations (wind, humidity, and atmospheric pressure) to the impact of solar wind and accumulation of charged solar particles.[6] Ice inside a cloud is thought to be a key element in lightning development, and may cause a forcible separation of positive and negative charges within the cloud, thus assisting in the formation of lightning.[6] For other uses, see Wind (disambiguation). ... The term humidity is usually taken in daily language to refer to relative humidity. ... Atmospheric pressure is the pressure at any given point in the Earths atmosphere. ... The plasma in the solar wind meeting the heliopause The solar wind is a stream of charged particles (i. ... This article is about water ice. ... Charge carrier denotes in physics a free (mobile, unbound) particle carrying an electric charge. ...

Contents

Early ideas and research about lightning

In the Christian faith, God is believed to be in command of the natural phenomena of lightning and thunderbolts. In the Book of Job God asks will lightning flash at your command? (Psalm 97:4 states, "His (God) lightnings light the world; The earth sees and trembles." Job 38:35). In his Dream Pool Essays written in AD 1088, the Song Dynasty polymath Chinese scientist Shen Kuo (1031-1095) wrote that when a house belonging to one Li Shunju had been struck by lightning, everyone assumed that the house would be burnt to the ground. To everyone's surprise, some of the wooden walls were merely blackened and lacquerwares untouched, while metal objects such as a steel sword were melted into liquid.[7] Shen compared this phenomenon to the equally strange effects of water being unable to douse Greek fire (which had been known to the Chinese since the Arabs had traded it, or a chemical composition fairly equal to it, in the 10th century).[7][8] For these strange effects of lightning, Shen wrote: The Book of Job (איוב) is one of the books of the Hebrew Bible. ... Shen Kuo (沈括) (1031-1095 AD) The Dream Pool Essays (Pinyin: Meng Xi Bi Tan; Wade-Giles: Meng Chi Pi Tan Chinese: 梦溪笔谈) was an extensive book written by the polymath Chinese scientist and statesman Shen Kuo (1031-1095) by 1088 AD, during the Song Dynasty (960-1279) of China. ... Northern Song in 1111 AD Capital Bianjing (汴京) (960–1127) Linan (臨安) (1127–1276) Language(s) Chinese Religion Buddhism, Taoism, Confucianism Government Monarchy Emperor  - 960–976 Emperor Taizu  - 1126–1127 Emperor Qinzong  - 1127–1162 Emperor Gaozong  - 1278–1279 Emperor Bing History  - Zhao Kuangyin taking over the throne of the Later Zhou... This is a Chinese name; the family name is Shen Shen Kuo or Shen Kua (Chinese: ; pinyin: ) (1031–1095) was a polymathic Chinese scientist and statesman of the Song Dynasty (960–1279). ... In a general sense, lacquer is a paint or varnish that produces a hard, durable finish that can be polished to a very high gloss, and gives the illusion of depth. ... For other uses, see Steel (disambiguation). ... Swiss longsword, 15th or 16th century Look up Sword in Wiktionary, the free dictionary. ... Greek fire was a burning-liquid weapon used by the Byzantine Greeks, typically in naval battles to great effect as it could continue burning even on water. ... For other uses, see Arab (disambiguation). ...

Most people can only judge of things by the experiences of ordinary life, but phenomena outside the scope of this are really quite numerous. How insecure it is to investigate natural principles using only the light of common knowledge, and subjective ideas.[7]

Thus was the frustration of learned men in his time of the desire to know the nature of lightning and other such common weather phenomena. However, in the Western world details of its force would become known by the 18th century. Occident redirects here. ...

Lightning strikes the Eiffel Tower in 1902.
Lightning strikes the Eiffel Tower in 1902.

Benjamin Franklin (1706-1790) endeavored to test the theory that sparks shared some similarity with lightning using a spire which was being erected in Philadelphia. While waiting for completion of the spire, he got the idea of instead using a flying object, such as a kite. During the next thunderstorm, which was in June 1752, it was reported that he raised a kite, accompanied by his son as an assistant. On his end of the string he attached a key, and he tied it to a post with a silk thread. As time passed, Franklin noticed the loose fibers on the string stretching out; he then brought his hand close to the key and a spark jumped the gap. The rain which had fallen during the storm had soaked the line and made it conductive. Image File history File links Metadata Size of this preview: 390 × 600 pixelsFull resolution (1030 × 1584 pixel, file size: 1. ... Image File history File links Metadata Size of this preview: 390 × 600 pixelsFull resolution (1030 × 1584 pixel, file size: 1. ... The Eiffel Tower (French: , ) is an iron tower built on the Champ de Mars beside the Seine River in Paris. ... Benjamin Franklin (January 17 [O.S. January 6] 1706 – April 17, 1790) was one of the most well known Founding Fathers of the United States. ... For other uses, see Philadelphia (disambiguation) and Philly. ... Yokaichi Giant Kite Festival held on the fourth Sunday every May in Higashiomi, Shiga, Japan Kite flying is the activity of flying tethered man-made objects in wind. ... A shelf cloud associated with a heavy or severe thunderstorm over Enschede, The Netherlands. ... For other uses of this word, see Silk (disambiguation). ...


Franklin was not the first to perform the kite experiment. Thomas-François Dalibard and De Lors conducted it at Marly-la-Ville in France a few weeks before Franklin's experiment.[9][10] In his autobiography (written 1771-1788, first published 1790), Franklin clearly states that he performed this experiment after those in France, which occurred weeks before his own experiment, without his prior knowledge as of 1752.[11] In 1750 the US scientist Benjamin Franklin published a proposal for an experiment to determine if lightning was electricity. ...


As news of the experiment and its particulars spread, people attempted to replicate it. However, experiments involving lightning are always risky and frequently fatal. The most well-known death during the spate of Franklin imitators was that of Professor George Richmann of Saint Petersburg, Russia. He created a set-up similar to Franklin's, and was attending a meeting of the Academy of Sciences when he heard thunder. He ran home with his engraver to capture the event for posterity. According to reports, while the experiment was under way, ball lightning appeared, collided with Richmann's head, killing him and leaving a red spot.[12][13] Richmann and his engrarver during the electrocution in St. ... Saint Petersburg (Russian: Санкт-Петербу́рг, English transliteration: Sankt-Peterburg), colloquially known as Питер (transliterated Piter), formerly known as Leningrad (Ленингра́д, 1924–1991) and Petrograd (Петрогра́д, 1914–1924), is a city located in Northwestern Russia on the delta of the river Neva at the east end of the Gulf of Finland... For other uses, see Thunder (disambiguation). ... For other uses, see Ball lightning (disambiguation). ...


Although experiments from the time of Franklin showed that lightning was a discharge of static electricity, there was little improvement in theoretical understanding of lightning (in particular how it was generated) for more than 150 years. The impetus for new research came from the field of power engineering: as power transmission lines came into service, engineers needed to know much more about lightning in order to adequately protect lines and equipment. Electrostatics (also known as static electricity) is the branch of physics that deals with the phenomena arising from what seem to be stationary electric charges. ... This article or section does not cite its references or sources. ... Power line redirects here. ...


Properties of lightning

World map showing frequency of lightning strikes, in flashes per km² per year (equal-area projection). Lightning strikes most frequently in the Democratic Republic of the Congo. Combined 1995–2003 data from the Optical Transient Detector and 1998–2003 data from the Lightning Imaging Sensor.
World map showing frequency of lightning strikes, in flashes per km² per year (equal-area projection). Lightning strikes most frequently in the Democratic Republic of the Congo. Combined 1995–2003 data from the Optical Transient Detector and 1998–2003 data from the Lightning Imaging Sensor.

An average bolt of lightning carries a negative electric current of 40 kiloamperes (kA) (although some bolts can be up to 120 kA), and transfers a charge of five coulombs and 500 MJ, or enough energy to power a 100 watt lightbulb for just under two months. The voltage depends on the length of the bolt, with the dielectric breakdown of air being three million volts per meter; this works out to approximately one gigavolt (one billion volts) for a 300 m (1000 ft) lightning bolt. With an electric current of 100 kA, this gives a power of 100 terawatts. However, lightning leader development is not a simple matter of dielectric breakdown, and the ambient electric fields required for lightning leader propagation can be a few orders of magnitude less than dielectric breakdown strength. Further, the potential gradient inside a well-developed return-stroke channel is on the order of hundreds of volts per meter or less due to intense channel ionization, resulting in a true power output on the order of megawatts per meter for a vigorous return-stroke current of 100 kA [14]. For other uses, see Ampere (disambiguation). ... The coulomb (symbol: C) is the SI unit of electric charge. ... The joule (IPA: or ) (symbol: J) is the SI unit of energy. ... For other uses, see Watt (disambiguation). ... The term electrical breakdown has several similar but distinctly different meanings. ... Josephson junction array chip developed by NIST as a standard volt. ... Josephson junction array chip developed by NIST as a standard volt. ... This page lists examples of the power in watts produced by various different sources of energy. ...


Lightning heats nearby air to about 10,000 °C (18,000 °F) nearly instantly, which is almost twice the temperature of the Sun’s surface. The heating creates a shock wave that is heard as thunder.[15] For other uses, see Celsius (disambiguation). ... For other uses, see Fahrenheit (disambiguation). ...


The return stroke of a lightning bolt follows a charge channel only about a centimeter (0.5-in) wide — no wider than a pencil. Most lightning bolts are about 1.6 kilometers (1 mi) long. The longest recorded length was 190 kilometers (118 mi), sighted near Dallas, Texas.[16]


Different locations have different potentials (voltages) and currents for an average lightning strike. For example, Florida, with the United States' largest number of recorded strikes in a given period during the summer season, has very sandy ground in some areas and conductive saturated mucky soil in others. As much of Florida lies on a peninsula, it is bordered by the ocean on three sides. The result is the daily development of sea and lake breeze boundaries that collide and produce thunderstorms. Arizona, which has very dry, sandy soil and a very dry air, has cloud bases as high as 1800-2100 m (6,000-7,000 ft) above ground level, and gets very long and thin purplish discharges which crackle; while Oklahoma, with cloud bases about 450-600 m (1,500-2,000 ft) above ground level and fairly soft, clay-rich soil, has big, blue-white explosive lightning strikes that are very hot (high current) and cause sudden, explosive noise when the discharge comes. The difference in each case may consist of differences in voltage levels between clouds and ground. Research on this is still ongoing.[citation needed]


NASA scientists have found the radio waves created by lightning clear a safe zone in the radiation belt surrounding the earth. This zone, known as the Van Allen Belt slot, can potentially be a safe haven for satellites, offering them protection from the Sun's radiation.[17][18][19] Van Allen radiation belts The Van Allen Radiation Belt is a torus of energetic charged particles (plasma) around Earth, held in place by Earths magnetic field. ...


Formation

Note
Positive lightning (a rarer form of lightning that originates from positively charged regions of the thundercloud) does not generally fit the following pattern.

Not to be confused with lighting. ...

Charge separation

The first process in the generation of lightning is charge separation.


Polarization mechanism hypothesis

The mechanism by which charge separation happens is still the subject of research, but one hypothesis is the polarization mechanism, which has two components:[20]

  1. Falling droplets of ice and rain become electrically polarized as they fall through the atmosphere's natural electric field;
  2. Colliding ice particles become charged by electrostatic induction.

Ice and supercooled water are the keys to the process. Violent winds buffet tiny hailstones as they form, causing them to collide. When the hailstones hit ice crystals, some negative ions transfer from one particle to another. The smaller particles lose negative ions and become positive and the larger more massive particles gain negative ions and become negative.[21] Electrostatic induction is a method by which an electrically charged object can be used to create an electrical charge in a second object, without contact between the two objects. ...


Electrostatic induction hypothesis

Another hypothesis is that opposite charges are driven apart by the above mechanism and energy is stored in the electric field between them. Cloud electrification appears to require strong updrafts which carry water droplets upward, supercooling them to between -10 and -20 °C. These collide with ice crystals to form a soft ice-water mixture called graupel. The collisions result in a slight positive charge being transferred to ice crystals, and a slight negative charge to the graupel. Updrafts drive lighter ice crystals upwards, causing the cloud top to accumulate increasing positive charge. The heavier negatively charged graupel falls towards the middle and lower portions of the cloud, building up an increasing negative charge. Charge separation and accumulation continue until the electrical potential becomes sufficient to initiate lightning discharges, which occurs when the gathering of positive and negative charges forms a sufficiently strong electric field. Supercool redirects here. ... Graupel can be any of the following types of solid-ice precipitation: hail - large chunks of ice such as from a strong or severe thunderstorm sleet - small pellets of raindrops that have frozen in mid-air, in winter or a thunderstorm snow pellets - when freezing fog forms 2-5mm balls... This article does not cite any references or sources. ...


There are several additional hypotheses for the origin of charge separation.[22]


Leader formation

As a thundercloud moves over the Earth's surface, an equal but opposite charge is induced in the Earth below, and the induced ground charge follows the movement of the cloud. Wikipedia does not yet have an article with this exact name. ...


An initial bipolar discharge, or path of ionized air, starts from a negatively charged mixed water and ice region in the thundercloud. The discharge ionized channels are called leaders. The negative charged leaders, called a "stepped leader", proceed generally downward in a number of quick jumps, each up to 50 meters long. Along the way, the stepped leader may branch into a number of paths as it continues to descend. The progression of stepped leaders takes a comparatively long time (hundreds of milliseconds) to approach the ground. This initial phase involves a relatively small electric current (tens or hundreds of amperes), and the leader is almost invisible compared to the subsequent lightning channel. ... Wikipedia does not yet have an article with this exact name. ... A step leader is a path of ionized air which extends downward from a thundercloud during the initial stages of atmospheric breakdown during a lightning strike. ... One millisecond is one-thousandth of a second. ... This box:      Electric current is the flow (movement) of electric charge. ... For other uses, see Ampere (disambiguation). ...


When a stepped leader approaches the ground, the presence of opposite charges on the ground enhances the electric field. The electric field is highest on trees and tall buildings. If the electric field is strong enough, a conductive discharge (called a positive streamer) can develop from these points. This was first theorized by Heinz Kasemir. As the field increases, the positive streamer may evolve into a hotter, higher current leader which eventually connects to the descending stepped leader from the cloud. It is also possible for many streamers to develop from many different objects simultaneously, with only one connecting with the leader and forming the main discharge path. Photographs have been taken on which non-connected streamers are clearly visible. When the two leaders meet, the electric current greatly increases. The region of high current propagates back up the positive stepped leader into the cloud with a "return stroke" that is the most luminous part of the lightning discharge. A step leader is a path of ionized air which extends downward from a thundercloud during the initial stages of atmospheric breakdown during a lightning strike. ... A positive streamer is the bit of a lightning bolt that rises from the ground before the lightning strikes, often determining the path of the cloud-to-ground lightning. ... Luminous intensity is a measure of the energy emitted by a light source in a particular direction. ...


Discharge

Lightning sequence (Duration: 0.32 seconds)
Lightning sequence (Duration: 0.32 seconds)

When the electric field becomes strong enough, an electrical discharge (the bolt of lightning) occurs within clouds or between clouds and the ground. During the strike, successive portions of air become a conductive discharge channel as the electrons and positive ions of air molecules are pulled away from each other and forced to flow in opposite directions. Image File history File links Download high resolution version (2554x240, 222 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Lightning ... Image File history File links Download high resolution version (2554x240, 222 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Lightning ... An electrostatic discharge (ESD) is a sudden flow of electric current through a material that is normally an insulator. ...


The electrical discharge rapidly superheats the discharge channel, causing the air to expand rapidly and produce a shock wave heard as thunder. The rolling and gradually dissipating rumble of thunder is caused by the time delay of sound coming from different portions of a long stroke.[23] In physics, superheating (sometimes referred to as boiling retardation, boiling delay, or defervescence) is the phenomenon in which a liquid is heated to a temperature higher than its standard boiling point, without actually boiling. ... Introduction The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. ...


Gurevich's runaway breakdown theory

Main article: Runaway breakdown

A theory of lightning initiation, known as the "runaway breakdown theory", proposed by Aleksandr Gurevich of the Lebedev Physical Institute in 1992 suggests that lightning strikes are triggered by cosmic rays which ionize atoms, releasing electrons that are accelerated by the electric fields, ionizing other air molecules and making the air conductive by a runaway breakdown, then "seeding" a lightning strike.[24][25][26] This article or section does not cite its references or sources. ... The Lebedev Physical Institute of the Russian Academy of Sciences is a Russian research institute specializing in physics. ... Cosmic rays can loosely be defined as energetic particles originating outside of the Earth. ...


Gamma rays and the runaway breakdown theory

Double lightning

It has been discovered in the past 15 years that among the processes of lightning is some mechanism capable of generating gamma rays, which escape the atmosphere and are observed by orbiting spacecraft. Brought to light by NASA's Gerald Fishman in 1994 in an article in Nature, these so-called Terrestrial Gamma-Ray Flashes (TGFs) were observed by accident, while he was documenting instances of extraterrestrial gamma ray bursts observed by the Compton Gamma Ray Observatory (CGRO). TGFs are much shorter in duration, however, lasting only ~1 ms. Image File history File linksMetadata Download high resolution version (3264x2448, 360 KB) Summary This picture was taken by me personally, from my balcony in Glyfada-Athens, during a storm. ... Image File history File linksMetadata Download high resolution version (3264x2448, 360 KB) Summary This picture was taken by me personally, from my balcony in Glyfada-Athens, during a storm. ... This article is about electromagnetic radiation. ... For other uses, see NASA (disambiguation). ... Nature is a prominent scientific journal, first published on 4 November 1869. ... Artists conception of gamma-ray burst and related phenomena. ...


Professor Umran Inan of Stanford University linked a TGF to an individual lightning stroke occurring within 1.5 ms of the TGF event,[27] proving for the first time that the TGF was of atmospheric origin and associated with lightning strikes. Stanford redirects here. ...


CGRO recorded only about 77 events in 10 years; however, more recently the RHESSI spacecraft, as reported by David Smith of UC Santa Cruz, has been observing TGFs at a much higher rate, indicating that these occur ~50 times per day globally (still a very small fraction of the total lightning on the planet). The energy levels recorded exceed 20 MeV. Reuven Ramaty High Energy Solar Spectroscopic Imager (or RHESSI) is a NASA sixthSmall Explorer, launched on 5 February 2002. ... “UCSC” redirects here. ...


Scientists from Duke University have also been studying the link between certain lightning events and the mysterious gamma ray emissions that emanate from the Earth's own atmosphere, in light of newer observations of TGFs made by RHESSI. Their study suggests that this gamma radiation fountains upward from starting points at surprisingly low altitudes in thunderclouds. Duke University is a private coeducational research university located in Durham, North Carolina, United States. ...


Steven Cummer, from Duke University's Pratt School of Engineering, said, "These are higher energy gamma rays than come from the sun. And yet here they are coming from the kind of terrestrial thunderstorm that we see here all the time."


Early hypotheses of this pointed to lightning generating high electric fields at altitudes well above the cloud, where the thin atmosphere allows gamma rays to easily escape into space, known as "relativistic runaway breakdown", similar to the way sprites are generated. Subsequent evidence has cast doubt, though, and suggested instead that TGFs may be produced at the tops of high thunderclouds. Though hindered by atmospheric absorption of the escaping gamma rays, these theories do not require the exceptionally high electric fields that high altitude theories of TGF generation rely on. Upper-atmospheric lightning is an early term sometimes invoked by researchers to refer to a family of electrical breakdown phenomena that occurs well above the altitudes of normal lightning. ...


The role of TGFs and their relationship to lightning remains a subject of ongoing scientific study.


Re-strike

Lightning is a highly visible form of energy transfer.
Lightning is a highly visible form of energy transfer.

High speed videos (examined frame-by frame) show that most lightning strikes are made up of multiple individual strokes. A typical strike is made of 3 to 4 strokes. There may be more.[23] Image File history File links Size of this preview: 800 × 534 pixelsFull resolution (1600 × 1067 pixel, file size: 125 KB, MIME type: image/jpeg) Lightning strike at Swifts Creek, looking west in January 2007. ... Image File history File links Size of this preview: 800 × 534 pixelsFull resolution (1600 × 1067 pixel, file size: 125 KB, MIME type: image/jpeg) Lightning strike at Swifts Creek, looking west in January 2007. ...


Each re-strike is separated by a relatively large amount of time, typically 40 to 50 milliseconds. Re-strikes can cause a noticeable "strobe light" effect.[23] An animation illustrating the effect of strobe light A strobe light or stroboscopic lamp, commonly called a strobe, is a device used to produce regular flashes of light. ...


Each successive stroke is preceded by intermediate dart leader strokes again to, but weaker than, the initial stepped leader. The stroke usually re-uses the discharge channel taken by the previous stroke.[23] A dart leader (also known as a continuous leader; may have been referred to by Feynman as a dark leader [citation needed]) is the cloud-to-ground movement of electrons which occurs just before a secondary lightning strike. ...


The variations in successive discharges are the result of smaller regions of charge within the cloud being depleted by successive strokes.[citation needed]


The sound of thunder from a lightning strike is prolonged by successive strokes. For other uses, see Thunder (disambiguation). ...


Types of lightning

Cloud-to-cloud lightning, Steinenbronn, Germany

Some lightning strikes take on particular characteristics; scientists and the public have given names to these various types of lightning. Most lightning is streak lightning. This is nothing more than the return stroke, the visible part of the lightning stroke. Because most of these strokes occur inside a cloud, we do not see many of the individual return strokes in a thunderstorm. Image File history File linksMetadata Size of this preview: 800 × 526 pixelsFull resolution (1598 × 1051 pixel, file size: 231 KB, MIME type: image/jpeg) Lightning over Steinenbronn, Germany Photo: Valerie Imre (uploader) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this... Image File history File linksMetadata Size of this preview: 800 × 526 pixelsFull resolution (1598 × 1051 pixel, file size: 231 KB, MIME type: image/jpeg) Lightning over Steinenbronn, Germany Photo: Valerie Imre (uploader) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this... Steinenbronn is a town in the district of Böblingen in Baden-Württemberg in Germany. ...


The return stroke of a lightning bolt, which is the visible bolt itself, follows a charge channel only about a half-inch (1.3 cm) wide. Most lightning bolts are about a mile (1.6 km) long.[28]


Positive lightning

See also: High_voltage#Lightning

Positive lightning, also known colloquially as a "bolt from the blue" makes up less than 5% of all lightning.[29] It occurs when the leader forms at the positively charged cloud tops, with the consequence that a negatively charged streamer issues from the ground. The overall effect is a discharge of positive charges to the ground. Research carried out after the discovery of positive lightning in the 1970s showed that positive lightning bolts are typically six to ten times more powerful than negative bolts, last around ten times longer, and can strike tens of kilometres/miles from the clouds.[30] The voltage difference for positive lightning must be considerably higher, due to the tens of thousands of additional metres/feet the strike must travel. During a positive lightning strike, huge quantities of ELF and VLF radio waves are generated.[31] In electrical engineering High voltage refers to a voltage which is high. ... A Bolt from the Blue is a term referring to a form of lightning that strikes in clear blue skies. ... “km” redirects here. ... This article is about the unit of length. ... Extremely low frequency (ELF) is the band of radio frequencies from 3 to 30 Hz. ... Very low frequency or VLF refers to radio frequencies (RF) in the range of 3 to 30 kHz. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ...


As a result of their greater power, positive lightning strikes are considerably more dangerous. At the present time, aircraft are not designed to withstand such strikes, since their existence was unknown at the time standards were set, and the dangers unappreciated until the destruction of a glider in 1999.[32] Flying machine redirects here. ... For other uses, see Glider (disambiguation). ...


Positive lightning is also now believed to have been responsible for the 1963 in-flight explosion and subsequent crash of Pan Am Flight 214, a Boeing 707.[citation needed] Subsequently, aircraft operating in U.S. airspace have been required to have lightning discharge wicks to reduce the chances of a similar occurrence. Pan Am Flight 214 was a domestic scheduled passenger flight whose loss dispelled the myth that airliners in flight were impervious to damage from lightning strikes. ... The Boeing 707 is an American four-engine commercial passenger jet airliner developed by Boeing in the early 1950s. ...


Positive lightning has also been shown to trigger the occurrence of upper atmosphere lightning. It tends to occur more frequently in winter storms and at the end of a thunderstorm.[33] A typical view of a winter storm. ... A shelf cloud associated with a heavy or severe thunderstorm over Enschede, The Netherlands. ...


An average bolt of positive lightning carries a current of up to 300 kA (kiloamperes) (about ten times as much current as a bolt of negative lightning), transfers a charge of up to 300 coulombs, has a potential difference up to 1 gigavolt (one billion volts), and lasts for hundreds of milliseconds, with a discharge energy of up to 300 GJ (gigajoules) (a billion joules).[citation needed] For other uses, see Ampere (disambiguation). ... The coulomb (symbol: C) is the SI unit of electric charge. ... Josephson junction array chip developed by NIST as a standard volt. ... The joule (IPA: or ) (symbol: J) is the SI unit of energy. ...


Anvil-to-ground

One special type of cloud-to-ground lightning is anvil-to-ground lightning. It is a form of positive lightning, since it emanates from the anvil top of a cumulonimbus cloud where the ice crystals are positively charged. The leader stroke issues forth in a nearly horizontal direction until it veers toward the ground. These usually occur kilometers/miles from (often ahead) of the main storm and will sometimes strike without warning on a sunny day. An anvil-to-ground lightning bolt is a sign of an approaching storm, and if one occurs in a largely clear sky, it is known colloquially as a "Bolt from the blue."[34] Cumulonimbus (Cb) is a type of cloud that is tall, dense, and involved in thunderstorms and other intense weather. ... A Bolt from the Blue is a term referring to a form of lightning that strikes in clear blue skies. ...


Cloud-to-cloud

Multiple paths of cloud-to-cloud lightning, Swifts Creek, Australia
Multiple paths of cloud-to-cloud lightning, Swifts Creek, Australia

Lightning discharges may occur between areas of cloud having different potentials without contacting the ground. These are most common between the anvil and lower reaches of a given thunderstorm. This lightning can sometimes be observed at great distances at night as so-called "heat lightning". In such instances, the observer may see only a flash of light without thunder. The "heat" portion of the term is a folk association between locally-experienced warmth and the distant lightning flashes. Image File history File links Size of this preview: 800 × 534 pixelsFull resolution (1600 × 1067 pixel, file size: 237 KB, MIME type: image/jpeg) Cloud to cloud lightning strike, March 2007, Swifts Creek If you are a (commercial) publisher and you want me to write you an email or paper... Image File history File links Size of this preview: 800 × 534 pixelsFull resolution (1600 × 1067 pixel, file size: 237 KB, MIME type: image/jpeg) Cloud to cloud lightning strike, March 2007, Swifts Creek If you are a (commercial) publisher and you want me to write you an email or paper... Swifts Creek is located between Omeo and Ensay on the Great Alpine Road of Victoria Categories: Australia-related stubs ...


Another terminology used for cloud-cloud or cloud-cloud-ground lightning is "Anvil Crawler", due to the habit of the charge typicallly originating from beneath or within the anvil and scrambling through the upper cloud layers of a thunderstorm, normally generating multiple branch strokes which are dramatic to witness. These are usually seen as a thunderstorm passes over you or begins to decay. The most vivid crawler behavior occurs in well developed thunderstorms that feature extensive rear anvil shearing.


Dry lightning

Dry lightning is a term in the United States for thunderstorms which produce no precipitation at the surface. This type of lightning is the most common natural cause of wildland fires. Dry lightning may also be referred to as heat lightning. Dry lightning is a term which is used in the United States to refer to thunderstorms which produce no rain at the surface. ...


Rocket lightning

Rocket Lightning, Queanbeyan, Australia
Rocket Lightning, Queanbeyan, Australia

It is a form of cloud discharge, generally horizontal and at cloud base, with a luminous channel appearing to advance through the air with visually resolvable speed, often intermittently.[35] Image File history File links Download high-resolution version (833x727, 30 KB) Lightning Storms over Queanbeyan NSW Australia February 2007 I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File links Download high-resolution version (833x727, 30 KB) Lightning Storms over Queanbeyan NSW Australia February 2007 I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... The town of Queanbeyan in New South Wales, Australia is overshadowed by its proximity to the Australian federal capital city of Canberra. ... In astronomy, geography, geometry and related sciences and contexts, a plane is said to be horizontal at a given point if it is locally perpendicular to the gradient of the gravity field, i. ...


The movement has been compared to that of a skyrocket, hence its name. It is also one of the rarest of cloud discharges.[36] A skyrocket is a type of firework that uses a solid rocket motor to rise quickly into the sky. ... For other uses, see Cloud (disambiguation). ...


Cloud-to-ground

Cloud-to-ground lightning is a great lightning discharge between a cumulonimbus cloud and the ground initiated by the downward-moving leader stroke. This is the second most common type of lightning, and poses the greatest threat to life and property of all known types.


Bead lightning

Bead lightning is a type of cloud-to-ground lightning which appears to break up into a string of short, bright sections, which last longer than the usual discharge channel. It is fairly rare. Several theories have been proposed to explain it; one is that the observer sees portions of the lightning channel end on, and that these portions appear especially bright. Another is that, in bead lightning, the width of the lightning channel varies; as the lightning channel cools and fades, the wider sections cool more slowly and remain visible longer, appearing as a string of beads.[37][38]


Ribbon lightning

Ribbon lightning occurs in thunderstorms with high cross winds and multiple return strokes. The wind will blow each successive return stroke slightly to one side of the previous return stroke, causing a ribbon effect.


Staccato lightning

Staccato lightning is nothing more than a leader stroke with only one return stroke.


Ground-to-cloud lightning

Ground-to-cloud lightning is a lightning discharge between the ground and a cumulonimbus cloud from an upward-moving leader stroke.


Ball lightning

Main article: Ball lightning

Ball lightning is described as a floating, illuminated ball that occurs during thunderstorms. They can be fast moving, slow moving or nearly stationary. Some make hissing or crackling noises or no noise at all. Some have been known to pass through windows and even dissipate with a bang. Ball lightning has been described by eyewitnesses but rarely recorded by meteorologists.[39] For other uses, see Ball lightning (disambiguation). ... Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting. ...


The engineer Nikola Tesla wrote, "I have succeeded in determining the mode of their formation and producing them artificially".[40] There is some speculation that electrical breakdown and arcing of cotton and gutta-percha wire insulation used by Tesla may have been a contributing factor, since some theories of ball lightning require the involvement of carbonaceous materials. Some later experimenters have been able to briefly produce small luminous balls by igniting carbon-containing materials atop sparking Tesla Coils. Nikola Tesla (1856-1943)[1] was a world-renowned Serbian inventor, physicist, mechanical engineer and electrical engineer. ... The term electrical breakdown has several similar but distinctly different meanings. ... An electric arc can melt calcium oxide. ... For other uses, see Cotton (disambiguation). ... Species About 100-120 species, including: Palaquium amboinense Palaquium barnesii Palaquium bataanense Palaquium beccarianum Palaquium borneense Palaquium burckii Palaquium clarkeanum Palaquium cochleariifolium Palaquium dasyphyllum Palaquium ellipticum Palaquium formosanum Palaquium galactoxylum Palaquium gutta Palaquium herveyi Palaquium hexandrum Palaquium hispidum Palaquium hornei Palaquium impressinervium Palaquium kinabaluense Palaquium lanceolatum Palaquium leiocarpum Palaquium lobbianum... Tesla Coil at Questacon, the Australian National Science Centre museum A Tesla coil (also teslacoil) is a type of resonant transformer, named after its inventor, Nikola Tesla. ...


Several theories have been advanced to describe ball lightning, with none being universally accepted. Any complete theory of ball lightning must be able to describe the wide range of reported properties, such as those described in Singer's book "The Nature of Ball Lightning" and also more contemporary research. Japanese research shows that several instances have been reported of ball lightning without any connection to stormy weather or lightning.


Ball lightning is typically 20 – 30 cm (8-12 inches) in diameter, but ball lightning several meters in diameter has been reported.[41] Ball lightning has been seen in tornadoes, and has also been seen to split apart into two or more separate balls and recombine, and vertically-linked fireballs have been reported.[citation needed] Ball lightning has carved trenches in the peat swamps in Ireland.[citation needed] Because of its strange behavior, ball lightning has been mistaken for a UFO by many witnesses. One theory that may account for this wider spectrum of observational evidence is the idea of combustion inside the low-velocity region of axisymmetric (spherical) vortex breakdown of a natural vortex (e.g., the 'Hill's spherical vortex').[42] This article is about the weather phenomenon. ... Peat in Lewis, Scotland Peat is an accumulation of partially decayed vegetation matter. ... This article does not cite any references or sources. ... UFO can mean: Unidentified flying object United Future Organization, a Japanese-Brazilian electronic jazz band UFO, the rock band that previously featured Michael Schenker UFO, the Gerry Anderson TV series United Farmers of Ontario, a political party that formed the government in Ontario from 1919 to 1923 U.F.O... This article is about the chemical reaction combustion. ... Vortex created by the passage of an aircraft wing, revealed by coloured smoke A vortex (pl. ... A vortex ring is a mass of moving fluid moving through the same or different fluid where the flow pattern takes on a donut shape. ...


Ball lightning apparently is created when lightning strikes silicon in soil, and has been created in a lab in this manner.[43]


Upper-atmospheric

Reports by scientists of strange lightning phenomena above storms date back to at least 1886. However, it is only in recent years that fuller investigations have been made.


Sprites

Main article: Upper-atmospheric lightning#Sprites
Sprites are now well-documented electrical discharges that occur high above some types of thunderstorms. They appear as luminous reddish-orange or greenish-blue, plasma-like flashes, last longer than normal lower stratospheric discharges (typically around 17 milliseconds), and are triggered by the discharges of positive lightning between the thundercloud and the ground.[31] Sprites often occur in clusters of two or more, and typically span the distance from 50 miles (80 km) to 90 miles (145 km) above the earth, with what appear to be tendrils hanging below, and branches reaching above. A 2007 paper reports that the apparent tendrils and branches of sprites are actually formed by bright streamer heads of less than 140 m diameter moving up or down at 1 to 10 percent of the speed of light.[44] The abstract is publicly accessible.[45][46][47]

Sprites may be horizontally displaced by up to 30 miles (48 km) from the location of the underlying lightning strike, with a time delay following the lightning that is typically a few milliseconds, but on rare occasions may be up to 100 milliseconds. Sprites are sometimes, but not always, preceded by a sprite halo, a broad, pancake-like region of transient optical emission centered at an altitude of about 47 miles (76 km) above lightning.[48] Sprite halos are produced by weak ionization from transient electric fields of the same type that causes sprites, but which are insufficiently intense to exceed the threshold needed for sprites. Sprites were first photographed on July 6, 1989 by scientists from the University of Minnesota. Several years after their discovery they were named after the mischievous sprite (air spirit) Puck in Shakespeare's Midsummer Night's Dream. Upper-atmospheric lightning is an early term sometimes invoked by researchers to refer to a family of electrical breakdown phenomena that occurs well above the altitudes of normal lightning. ... For other uses, see Plasma. ... The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning swiftness.[1] It is the speed of all electromagnetic radiation, including visible light, in a vacuum. ... This article is about the oldest and largest campus of the University of Minnesota. ... Wikipedia does not yet have an article with this exact name. ... Midsummer Nights Dream is the second episode of the Oh My Goddess! OVA series, and was originally released on 1993-05-21. ...


Recent research carried out at the University of Houston in 2002 indicates that some normal (negative) lightning discharges produce a sprite halo, the precursor of a sprite, and that every lightning bolt between cloud and ground attempts to produce a sprite or a sprite halo.[citation needed] Research in 2004 by scientists from Tohoku University found that very low frequency emissions occur at the same time as the sprite, indicating that a discharge within the cloud may generate the sprites.[45] For other system schools, see University of Houston System. ... This article is Tohoku University in Japan. ... Very low frequency or VLF refers to radio frequencies (RF) in the range of 3 to 30 kHz. ...


Blue jets

Blue jets differ from sprites in that they project from the top of the cumulonimbus above a thunderstorm, typically in a narrow cone, to the lowest levels of the ionosphere 25 miles (40 km) to 30 miles (48 km) above the earth.[citation needed] They are also brighter than sprites and, as implied by their name, are blue in color. They were first recorded on October 21, 1989, on a video taken from the space shuttle as it passed over Australia, and subsequently extensively documented in 1994 during aircraft research flights by the University of Alaska.[49][50][47] Relationship of the atmosphere and ionosphere The ionosphere is the uppermost part of the atmosphere, distinguished because it is ionized by solar radiation. ... is the 294th day of the year (295th in leap years) in the Gregorian calendar. ... Year 1989 (MCMLXXXIX) was a common year starting on Sunday (link displays 1989 Gregorian calendar). ... This article is about the space vehicle. ...


On September 14, 2001, scientists at the Arecibo Observatory photographed a huge jet double the height of those previously observed, reaching around 50 miles (80 km) into the atmosphere. The jet was located above a thunderstorm over the ocean, and lasted under a second. Lightning was initially observed traveling up at around 50,000 m/s in a similar way to a typical blue jet, but then divided in two and sped at 250,000 m/s to the ionosphere, where they spread out in a bright burst of light.[51] On July 22, 2002, five gigantic jets between 60 and 70 km (35 to 45 miles) in length were observed over the South China Sea from Taiwan, reported in Nature.[49] The jets lasted under a second, with shapes likened by the researchers to giant trees and carrots.[citation needed] is the 257th day of the year (258th in leap years) in the Gregorian calendar. ... Year 2001 (MMI) was a common year starting on Monday (link displays the 2001 Gregorian calendar). ... The Arecibo Observatory is located approximately 9 miles south-southwest from Arecibo, Puerto Rico (near the extreme southwestern corner of Arecibo pueblo). ... is the 203rd day of the year (204th in leap years) in the Gregorian calendar. ... Also see: 2002 (number). ... Filipino name Tagalog: Timog Dagat Tsina (Dagat Luzon for the portion within Philippine waters) Malay name Malay: Laut China Selatan Portuguese name Portuguese: Mar da China Meridional Vietnamese name Vietnamese: The South China Sea is a marginal sea south of China. ...


In 2001, the Arecibo scientists modeled the blue-jet phenomenon to better understand how it works. It is like an electron avalanche that can flood up toward the ionosphere or slide earthward, depending on the electric field direction. Intense hail may trigger the avalanche. The field accelerates the electrons and slams them into air molecules. The molecules break down into ions and free electrons and emit light. The newly generated electrons also accelerate.[50] For other uses, see Electron (disambiguation). ... In physics, the space surrounding an electric charge or in the presence of a time-varying magnetic field has a property called an electric field. ... This article is about the electrically charged particle. ... For other uses, see Electron (disambiguation). ...


Elves

Elves often appear as a dim, flattened, expanding glow around 250 miles (402 km) in diameter that lasts for, typically, just one millisecond.[52] They occur in the ionosphere 60 miles (97 km) above the ground over thunderstorms. Their color was a puzzle for some time, but is now believed to be a red hue. Elves were first recorded on another shuttle mission, this time recorded off French Guiana on October 7, 1990. Elves is a frivolous acronym for Emissions of Light and Very Low Frequency Perturbations From Electromagnetic Pulse Sources. This refers to the process by which the light is generated; the excitation of nitrogen molecules due to electron collisions (the electrons possibly having been energized by the electromagnetic pulse caused by a discharge from the Ionosphere).[47] is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... This article is about the year. ... For alternate meanings, see Lightning (disambiguation). ... It has been suggested that this article or section be merged with Backronym and Apronym (Discuss) Acronyms and initialisms are abbreviations, such as NATO, laser, and ABC, written as the initial letter or letters of words, and pronounced on the basis of this abbreviated written form. ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... For other uses, see Electron (disambiguation). ...


Triggered lightning

Rocket-triggered

Volcanic material thrust high into the atmosphere can trigger spectacular lightning.
Volcanic material thrust high into the atmosphere can trigger spectacular lightning.

Lightning has been triggered directly by human activity in several instances. Lightning struck the Apollo 12 soon after takeoff, and has struck soon after thermonuclear explosions.[53] It has also been triggered by launching lightning rockets carrying spools of wire into thunderstorms. The wire unwinds as the rocket ascends, providing a path for lightning. These bolts are typically very straight due to the path created by the wire.[54] Image File history File linksMetadata Rinjani_1994. ... Image File history File linksMetadata Rinjani_1994. ... Apollo 12 was the sixth manned mission in the Apollo program and the second to land on the Moon. ... At the end of the 20th century, Thermonuclear has came to imply anything which has to do with fusion nuclear reactions which are triggered by particles of thermal energy. ... A lightning rocket consists of a rocket launcher that is in communication with a detection device that measures the presence of electrostatic and ionic change in close proximity to the rocket launcher that also fires the rocket launcher. ...


Flying aircraft can trigger lightning.[55]


Volcanically-triggered

Extremely large volcanic eruptions, which eject gases and material high into the atmosphere, can trigger lightning. This phenomenon was documented by Pliny The Elder during the AD79 eruption of Vesuvius, in which he perished.[56] Pliny the Elder: an imaginative 19th Century portrait. ... Mount Vesuvius (Italian: Monte Vesuvio) is a volcano east of Naples, Italy, located at 40°49′N 14°26′ E. It is the only active volcano on the European mainland, although it is not currently erupting. ...


Laser-triggered

Since at least the 1970s, researchers have attempted to trigger lightning strikes by means of ultra-violet lasers, which create a channel of ionized gas through which the lightning would be conducted to ground. Such triggered lightning is intended to protect rocket launching pads, electric power facilities, and other sensitive targets.[57][58][59][60][61][62]


Extraterrestrial lightning

Lightning requires the electrical breakdown of a gas, so it cannot exist in a visual form in the vacuum of space. However, lightning has been observed within the atmospheres of other planets, such as Venus, Jupiter and Saturn. Lightning on Venus is still a controversial subject after decades of study. During the Soviet Venera and U.S. Pioneer missions of the 1970s and '80s, signals suggesting lightning may be present in the upper atmosphere were detected.[63] However, recently the Cassini-Huygens mission fly-by of Venus detected no signs of lightning at all. In 2007, however, radio pulses recorded by the spacecraft Venus Express confirmed lightning on Venus.(S&T, Mar. 2008) Look up Vacuum in Wiktionary, the free dictionary. ... Atmosphere is the general name for a layer of gases that may surround a material body of sufficient mass. ... This article is about the astronomical term. ... For other uses, see Venus (disambiguation). ... For other uses, see Jupiter (disambiguation). ... This article is about the planet. ... Venera 7 lander Color image taken from the surface of Venus by the Soviet Venera 13 lander The Venera (Russian: Венера; formerly, sometimes referred to as Venusik in the West) series of probes was developed by the USSR to gather data from Venus. ... The US Pioneer program of unmanned space missions was designed for planetary exploration. ... Cassini-Huygens is a joint NASA/ESA/ASI unmanned space mission intended to study Saturn and its moons. ...


Trees and lightning

Lightning damage to tree in Maplewood, NJ
Lightning damage to tree in Maplewood, NJ
Eucalyptus tree that was blown apart by a lightning strike
Eucalyptus tree that was blown apart by a lightning strike

Trees are frequent conductors of lightning to the ground.[64] Since sap is a poor conductor, its electrical resistance causes it to be heated explosively into steam, which blows off the bark outside the lightning's path. In following seasons trees overgrow the damaged area and may cover it completely, leaving only a vertical scar. If the damage is severe, the tree may not be able to recover, and decay sets in, eventually killing the tree. It is commonly thought that a tree standing alone is more frequently struck, though in some forested areas, lightning scars can be seen on almost every tree. Image File history File links Metadata Size of this preview: 398 × 599 pixelsFull resolution (2000 × 3008 pixel, file size: 2. ... Image File history File links Metadata Size of this preview: 398 × 599 pixelsFull resolution (2000 × 3008 pixel, file size: 2. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution‎ (1,255 × 941 pixels, file size: 357 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution‎ (1,255 × 941 pixels, file size: 357 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... This article is about the plant genus. ... The coniferous Coast Redwood, the tallest tree species on earth. ... In science and engineering, conductors are materials that contain movable charges of electricity. ... Sap exuding (gummosis) from the stem of a koa tree, probably in response to surface damage Sap is the fluid carried in tubules inside a plant, circulating to distribute food and water to various parts of the plant. ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ... A steam explosion (also called a littoral explosion, or fuel-coolant interaction, FCI) is a violent boiling or flashing of water into steam, occurring when water is either superheated, or rapidly heated by fine hot debris produced within it. ... For other uses, see Steam (disambiguation). ... For other uses, see Bark (disambiguation). ... “Spoilage” redirects here. ... This article is about a community of trees. ...

Three eucalyptus trees that were struck by lightning, Walcha, NSW
Three eucalyptus trees that were struck by lightning, Walcha, NSW

After the two most frequently struck tree types, the Oak and the Elm,[65] the Pine tree is also quite often hit by lightning. Unlike the Oak, which has a relatively shallow root structure, pine trees have a deep central root system that goes down into the water table.[66] Pine trees usually stand taller than other species, which also makes them a likely target. Factors which lead to its being targeted are a high resin content, loftiness, and its needles which lend themselves to a high electrical discharge during a thunderstorm. Walcha is a town in the north of New South Wales, Australia, and serves as the seat of Walcha Shire. ... Species See List of Quercus species The term oak can be used as part of the common name of any of several hundred species of trees and shrubs in the genus Quercus (from Latin oak tree), which are listed in the List of Quercus species, and some related genera, notably... Species See Elm species, varieties, cultivars and hybrids Elms are deciduous and semi-deciduous trees making up the genus Ulmus, family Ulmaceae, found throughout the Northern Hemisphere from Siberia to Indonesia, Mexico to Japan. ... Subgenera Subgenus Strobus Subgenus Ducampopinus Subgenus Pinus See Pinus classification for complete taxonomy to species level. ... For other uses, see Root (disambiguation). ...


Trees are natural lightning conductors, and are known to provide protection against lightning damages to the nearby buildings. Tall trees with high biomass for the root system provide good lightning protection. An example is the teak tree (Tectona grandis), which grows to a height of 45 metres (147.6 ft). It has a spread root system with a spread of 5 m and a biomass of 4 times that of the trunk; its penetration into the soil is 1.25 metres (4.10 ft) and has no tap root. When planted near a building, its height helps in catching the oncoming lightning leader, and the high biomass of the root system helps in dissipation of the lightning charges.[67] Species Tectona grandis Tectona hamiltoniana Tectona philippinensis Teak (Tectona), also called jati is a genus of tropical hardwood trees in the family Verbenaceae, native to the south and southeast of Asia, and is commonly found as a component of monsoon forest vegetation. ...


Lightning currents have a very fast risetime, on the order of 40 kA per microsecond. Hence, conductors of such currents exhibit marked skin effect, causing most of the currents to flow through the conductor skin.[68] The effective resistance of the conductor is consequently very high and therefore, the conductor skin gets heated up much more than the conductor core. When a tree acts as a natural lightning conductor, due to skin effect most of the lightning currents flow through the skin of the tree and the sap wood. As a result, the skin gets burnt and may even peel off. The moisture in the skin and the sap wood evaporates instantaneously and may get split. If the tree struck by lightning is a teak tree (single stemmed with branches) it may not be completely destroyed since only the tree skin and a branch may be affected; the major parts of the tree may be saved from complete destruction due to lightning currents. But if the tree involved is a coconut tree it may be completely destroyed by the lightning currents.[citation needed] In electronics, when describing a voltage or current step function, rise time (also risetime) refers to the time required for a signal to change from a specified low value to a specified high value. ... The skin effect is the tendency of an alternating electric current (AC) to distribute itself within a conductor so that the current density near the surface of the conductor is greater than that at its core. ... For other uses, see Coconut (disambiguation). ...


Lightning-induced magnetism

Lightning induced remanent magnetization (LIRM) mapped during a magnetic field gradient survey of an archaeological site located in Wyoming (USA)
Lightning induced remanent magnetization (LIRM) mapped during a magnetic field gradient survey of an archaeological site located in Wyoming (USA)

The movement of electrical charges produces a magnetic field (see Electromagnetism). The intense currents of a lightning discharge create a fleeting but very strong magnetic field. Where the lightning current path passes through rock, soil, or metal these materials can become permanently magnetized. This effect is known as lightning-induced remanent magnetism, or LIRM. These currents follow the least resistive path, often horizontally near the surface[69] but sometimes vertically, where faults, ore bodies, or ground water offers a less resistive path.[70] Lightning-induced Magnetic anomalies can be mapped in the ground,[71][72] and analysis of magnetized materials can confirm lightning was the source of the magnetization[73] and provide an estimate of the peak current of the lightning discharge.[74] Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ...


Records and locations

On average, lightning flashes occur on earth about 100 times every second. 80% of these flashes are in-cloud and 20% are cloud-to-ground.[citation needed] For most landmasses, lightning strikes most often during the summer, limiting the strike numbers. The spot with the most lightning lies deep in the mountains of eastern Democratic Republic of the Congo, near the small village of Kifuka which has an elevation of 3,200 feet (975 m). Thunderbolts pelt this land, and each year on average, 158 bolts occur over each square kilometer (equivalent to 10 city-blocks square).[75] Singapore has one of the highest rates of lightning activity in the world.[76] The city of Teresina in northern Brazil has the third-highest rate of occurrences of lightning strikes in the world. The surrounding region is referred to as the Chapada do Corisco ("Flash Lightning Flatlands").[77] In the US, Central Florida sees more lightning than any other area. For example, in what is called "Lightning Alley", an area from Tampa, to Orlando, there are as many as 50 strikes per square mile (about 20 per km²) per year.[78][79] The Empire State Building is struck by lightning on average 23 times each year, and was once struck 8 times in 24 minutes.[80] Teresina (formerly written Theresina) is the capital and largest city of the Brazilian state of Piauí and the only inland capital in the northeastern region of the country. ... This article is about the U.S. State of Florida. ... Tampa redirects here. ... Nickname: Location in Orange County and the state of Florida Coordinates: , Country State County Government  - Mayor Buddy Dyer (D) Area  - City 261. ... The Empire State Building is a 102-story Art Deco skyscraper in New York City, New York at the intersection of Fifth Avenue and West 34th Street. ...


Roy Sullivan held a Guinness World Record after surviving 7 different lightning strikes across 35 years.[81] Roy Cleveland Sullivan (February 7, 1912 – September 28, 1983)[1][2] was a U.S. forest ranger in Shenandoah National Park in Virginia. ... The Guinness Book of Records (or in recent editions Guinness World Records, and in previous US editions Guinness Book of World Records) is a book published annually, containing an internationally recognized collection of superlatives: both in terms of human achievement and the extrema of the natural world. ...


In July 2007, lightning killed up to 30 people when it struck a remote mountain village Ushari Dara in northwestern Pakistan.[82]


Lightning can also strike indoor pools, directed into the pump by electrical circuits from outdoor power poles. Such strikes could potentially kill people who are swimming or walking on wet floors around a pool. In 2000, lightning killed two boys in an outdoor pool in Florida.[83]


A single lightning strike can have a potential of a billion volts and deliver 100,000 amperes of current. If a bolt directly hits a marine animal swimming on the surface, it will undoubtedly hurt or kill the animal. Lightning strikes have killed or injured people on the surface more than 30 yards away.[84]


On 31 October 2005, sixty-eight dairy cows, all in full milk, died on a farm at Fernbrook on the Waterfall Way near Dorrigo, New South Wales after being struck by lightning. Three others were paralysed for several hours but they later made a full recovery. The cows were sheltering under a tree when it was struck by lightning and the electricty spread onto the surrounding soil killing the animals.[85] The Waterfall Way is a State Route (number 78) in New South Wales. ... Dorrigo is a small town inland from the Mid North Coast of New South Wales, Australia, in Bellingen Shire Council. ...


Lightning rarely strikes the open ocean, although some sea regions are lightning "hot spots." Winter storms passing off the east coast of the United States often erupt with electrical activity when they cross the warm waters of the Gulf Stream.[86]The Gulf Stream, for example, has roughly as many lightning strikes as the southern plains of the USA.


Lightning detection

Lightning discharges generate a wide range of electromagnetic radiations, including radio-frequency pulses. The times at which a pulse from a given lightning discharge arrive at several receivers can be used to locate the source of the discharge. The United States federal government has constructed a nation-wide grid of such lightning detectors, allowing lightning discharges to be tracked in real time throughout the continental U.S.[87][88]


In addition to ground-based lightning detection, several instruments aboard satellites have been constructed to observe lightning distribution. These include the Optical Transient Detector (OTD), aboard OrbView-1 satellite launched on April 3, 1995, and the subsequent Lightning Imaging Sensor (LIS) aboard TRMM launched on November 28, 1997.[89][90][91] Artist conception of the TRMM satellite. ...

Lightning is a highly visible form of energy transfer. ...

Most spectacular lightning strike incidences

In spite of many precaution measures as lightning rods even still today several spectacular lightning incidences occurred either with people killed or great damage. The following incomplete list shows some cases An example of a standard, pointed-tip air terminal The term lightning rod is also used as a metaphorical term to describe those who attract controversy. ...

  • 1902: A lightning damaged the upper section of Eiffel Tower requiring the reconstruction of its top [1]
  • December 8th, 1963: Pan Am Flight 214 crashed as result of lightning strike, 81 people killed.
  • July 1970, central mast of Orlunda radio transmitter collapsed after lightning strike destroyed its basement insulator
  • December 24th, 1971: LANSA Flight 508 crashed as result of lightning in Peru, 91 people killed.

The Eiffel Tower (French: , ) is an iron tower built on the Champ de Mars beside the Seine River in Paris. ... Pan Am Flight 214 was a domestic scheduled passenger flight whose loss dispelled the myth that airliners in flight were impervious to damage from lightning strikes. ... LANSA Flight 508 was a Lockheed Electra L-188A turboprop, registered OB-R-941, operated by Lineas Aéreas Nacionales Sociedad Anonima (LANSA), that crashed in a thunderstorm enroute from Lima, Peru to Pucallpa, Peru, on December 24, 1971, killing 91 of its 6 crew and 86 passengers. ... Image File history File links This is a lossless scalable vector image. ...

In culture

As expressions and symbols

The expression "Lightning never strikes twice [in the same place]" is similar to "Opportunity never knocks twice" in the vein of a "once in a lifetime" opportunity, i.e., something that is generally considered improbable. Lightning occurs frequently and more so in specific areas. Since various factors alter the probability of strikes at any given location, repeat lightning strikes have a very low probability (but are not impossible).[80][92] Similarly, "A bolt from the blue" refers to something totally unexpected. Not to be confused with lighting. ... Not to be confused with lighting. ... Not to be confused with lighting. ... Probability is the likelihood that something is the case or will happen. ...


In French and Italian, the expression for "Love at first sight" is Coup de foudre and Colpo di fulmine, respectively, which literally translated means "Bolt of lightning". Some European languages have a separate word for lightning which strikes the ground (as opposed to lightning in general); often it is a cognate of the English word "rays". The name of New Zealand's most celebrated thoroughbred horse, Phar Lap, derives from the shared Zhuang and Thai word for lightning.[citation needed] Look up cognate in Wiktionary, the free dictionary. ... For the processor with the same codename , see Athlon. ... For the computer software, see: Phar Lap (company). ... The Zhuang (Simplified Chinese: 壮族; Traditional Chinese: 壯族; Hanyu Pinyin: ; own name: Bouчcueŋь/Bouxcuengh) are an ethnic group of people who mostly live in the Guangxi Zhuang Autonomous Region in southern China. ...


The bolt of lightning in heraldry is called a thunderbolt and is shown as a zigzag with non-pointed ends. This symbol usually represents power and speed; and thus has been used to represent the Greek god Zeus, as well as many advertisements which use such symbol to describe their product. It is also distinguished from the "fork of lightning". The lightning bolt shape was a symbol of male humans among the Native Americans such as the Apache in the American Old West.[citation needed] Heraldry in its most general sense encompasses all matters relating to the duties and responsibilities of officers of arms. ... Typical cartoon representations of thunderbolts A thunderbolt is a traditional expression for a discharge of lightning or a symbolic representation thereof. ... The bust of Zeus found at Otricoli (Sala Rotonda, Museo Pio-Clementino, Vatican) Greek mythology is the body of stories belonging to the Ancient Greeks concerning their gods and heroes, the nature of the world and the origins and significance of their own cult and ritual practices. ... For other uses, see Zeus (disambiguation). ... This article is about the people indigenous to the United States. ... For other uses, see Apache (disambiguation). ... The cowboy, the quintessential symbol of the American Old West, circa 1887. ...


Media

In Michael Crichton's State of Fear the terrorists use lightning to assassinate enemies. State of Fear is a 2004 novel by Michael Crichton published by HarperCollins on December 7, 2004. ...


Hugo Danner, the super-powered protagonist of Philip Gordon Wylie's 1930 novel Gladiator and the inspiration for Superman,[93] was ultimately killed by a lightning bolt as he stood on a mountain top challenging God's power.[94] Hugo Danner is the protagonist of the 1930 novel Gladiator, by Philip Gordon Wylie. ... Philip Gordon Wylie (May 12, 1902 – October 25, 1971) was a U.S. author. ... Gladiator is an American science fiction novel first published in 1930 and written by Philip Wylie. ... Superman is a fictional character and comic book superhero , originally created by American writer Jerry Siegel and Canadian artist Joe Shuster and published by DC Comics. ...


See also

Cloud-to-ground lightning in Algiers (Algeria) Heat lightning (or, in the UK, summer lightning) is a misnomer for the faint flashes of lightning on the horizon or other clouds from distant thunderstorms that do not have accompanying sounds of thunder. ... Lightning is a highly visible form of energy transfer. ... An example of a standard, pointed-tip air terminal The term lightning rod is also used as a metaphorical term to describe those who attract controversy. ... Keraunomedicine is the medical study of lightning casualties. ... This article or section does not cite its references or sources. ... A frequency vs. ... A Whistler is a very low frequency radio wave generated by lightning. ... Robert Krampfs electricity show has garnered him the name Mr. ...

References

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  2. ^ Munoz, Rene (2003). Factsheet: Lightning. University Corporation for Atmospheric Research. Retrieved on November 7, 2007.
  3. ^ Rakov, Vladimir A. (1999). Lightning Makes Glass. University of Florida, Gainesville. Retrieved on November 7, 2007.
  4. ^ USGS (1998). Bench collapse sparks lightning, roiling clouds. United States Geological Society. Retrieved on September 21, 2007.
  5. ^ Micah Fink for PBS. How Lightning Forms. Public Broadcasting System. Retrieved on September 21, 2007.
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  8. ^ Needham, Joseph (1986). "Science and Civilization in China: Chemistry and Chemical Technology Part 7, Military Technology" Volume 5: Pages 80-82. Caves Books Ltd. 
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  10. ^ E. Philip Krider (2004). pdf file Benjamin Franklin and the First Lightning Conductors (.pdf). Proceedings of International Commission on History of Meteorology. Retrieved on September 24, 2007.
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  47. ^ Cite error: Invalid <ref> tag; no text was provided for refs named holo
  48. ^ Cite error: Invalid <ref> tag; no text was provided for refs named pesn
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  69. ^ Graham KWT. 1961. The Re-magnetization of a Surface Outcrop by Lightning Currents. Geophys. J. Roy. Astron Soc., 6, p.85-102; Cox A. 1961. Anomalous Remanent Magnetization of Basalt. U.S. Geological Survey Bulletin 1038-E, p. 131-160.
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  74. ^ Verrier V, Rochette P. 2002 Estimating Peak Currents at Ground Lightning Impacts Using Remanent Magnetization. Geophysical Research Letters, Vol. 29, No. 18, p. 14-1-4.
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  77. ^ Paesi Online. Teresina: Vacations and Tourism. Paesi Online. Retrieved on September 24, 2007.
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  79. ^ Kevin Pierce (2000). Summer Lightning Ahead. Florida Environment.com. Retrieved on September 24, 2007.
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  81. ^ "ROY SULLIVAN", The New York Times Archives (from UPI), September 30, 1983. Retrieved on 2007-07-28. 
  82. ^ "Lightning kills 30 people in Pakistan's north", Reuters, July 20, 2007. Retrieved on 2007-07-27. 
  83. ^ Everybody out of the pool!
  84. ^ Lightning strikes fish
  85. ^ Lightning kills 106 cows
  86. ^ Lightning strikes fish
  87. ^ Lightning Detection Systems, <http://www.nwstc.noaa.gov/METEOR/Lightning/detection.htm>. Retrieved on 27 July 2007 NOAA page on how the U.S. national lightning detection system operates
  88. ^ Vaisala Thunderstorm Online Application Portal, <https://thunderstorm.vaisala.com/tux/jsp/explorer/explorer.jsp>. Retrieved on 27 July 2007 Real-time map of lightning discharges in U.S.
  89. ^ NASA (2007). NASA Dataset Information. NASA. Retrieved on September 11, 2007.
  90. ^ NASA (2007). NASA LIS Images. NASA. Retrieved on September 11, 2007.
  91. ^ NASA (2007). NASA OTD Images. NASA. Retrieved on September 11, 2007.
  92. ^ Jesus actor struck by lightning. BBC News International Version (October 23, 2003). Retrieved on 2007-08-19.
  93. ^ Jones, Gerard. Men of Tomorrow: Geeks, Gangsters, and the Birth of the Comic Book. New York: Basic Books, 2004 (ISBN 0465036562), pg. 80
  94. ^ Wylie, Philip. Gladiator. New York: Shakespeare House. 1951, pg. 187

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... ISSN, or International Standard Serial Number, is the unique eight-digit number applied to a periodical publication including electronic serials. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... For other uses, see NASA (disambiguation). ... For other uses, see NASA (disambiguation). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 186th day of the year (187th in leap years) in the Gregorian calendar. ... is the 346th day of the year (347th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... The University of Colorado at Boulder (CU or CU-Boulder) is the flagship university of the University of Colorado system. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 210th day of the year (211th in leap years) in the Gregorian calendar. ... Dr. Martin A. Uman has been acknowledged by the American Geophysical Union as one of the worlds leading authorities on lightning. ... is the 252nd day of the year (253rd in leap years) in the Gregorian calendar. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 208th day of the year (209th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 268th day of the year (269th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 186th day of the year (187th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 186th day of the year (187th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 212th day of the year (213th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... The Royal Meteorological Society traces its origins back to April 3, 1850 when the British Meteorological Society was formed as a society the objects of which should be the advancement and extension of meteorological science by determining the laws of climate and of meteorological phenomena in general. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 342nd day of the year (343rd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 186th day of the year (187th in leap years) in the Gregorian calendar. ... The University of New Mexico (UNM) is a public university in Albuquerque, New Mexico. ... is the 29th day of the year in the Gregorian calendar. ... Year 2001 (MMI) was a common year starting on Monday (link displays the 2001 Gregorian calendar). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 209th day of the year (210th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... For other uses, see NASA (disambiguation). ... For other uses, see NASA (disambiguation). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 273rd day of the year (274th in leap years) in the Gregorian calendar. ... Year 1983 (MCMLXXXIII) was a common year starting on Saturday (link displays the 1983 Gregorian calendar). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 209th day of the year (210th in leap years) in the Gregorian calendar. ... is the 201st day of the year (202nd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 208th day of the year (209th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 231st day of the year (232nd in leap years) in the Gregorian calendar. ...

Sources

  • My Very Close Encounters With Florida Lightning Bolts By Thomas F. Giella, Retired Meteorologist & Space Plasma Physicist
  • Alex Larsen (1905). "Photographing Lightning With a Moving Camera". Annual Report Smithsonian Institute 60 (1): 119-127. 
  • André Anders (2003). "Tracking Down the Origin of Arc Plasma Science I. Early Pulsed and Oscillating Discharges". IEEE Transactions on Plasma Science 31 (4): 1052-1059.  This is also available at [2]
  • Anna Gosline (May 2005). "Thunderbolts from space". New Scientist 186 (2498): 30-34. 
  • Martin A. Uman (1986). All About Lightning. Dover Publications, Inc.. ISBN 0-486-25237-X.  This book is written for the layman.
  • V. A. Rakov; Martin A. Uman (2003). Lightning, physics and effects. Cambridge University Press. ISBN 0-521-58327-6.  Sample, in .pdf form, consisting of all of the book through page 20.
  • The Mirror of Literature, Amusement, and Instruction, Vol. 12, Issue 323, July 19, 1828 The Project Gutenberg eBook (early lightning research)

New Scientist is a weekly international science magazine covering recent developments in science and technology for a general English-speaking audience. ... Dr. Martin A. Uman has been acknowledged by the American Geophysical Union as one of the worlds leading authorities on lightning. ... Dr. Martin A. Uman has been acknowledged by the American Geophysical Union as one of the worlds leading authorities on lightning. ...

External links

Wikimedia Commons has media related to:
Look up Lightning in
Wiktionary, the free dictionary.
  • How to survive in a lightning storm A guide for children and youth
  • How Lightning Works at HowStuffWorks
  • "1.21 Gigawatts!" Lightning safety and first-aid in the backcountry
  • dmoz: Thunderstorms and Lightning
  • Lightning Safety Page - National Weather Service Pueblo Colorado Citat: "...This is known as a "side flash". Many people who are "struck" by lightning are not hit directly by the main lightning channel, but are affected by the side flash..."
  • Colorado Lightning Resource Center
  • Webarchive: April 25, 1997 Sandia-led research may zap old beliefs about lightning protection at critical facilities; Triggered lightning tests leading to safer storage bunkers
  • 2003-11-06, ScienceDaily: Thunderstorm Research Shocks Conventional Theories; Florida Tech Physicist Throws Open Debate On Lightning's Cause
  • Austrian Lightning Detection and Information System
  • European Cooperation for Lightning Detection
  • United States Precision Lightning Network - Live lightning data map
  • NASA Finds Lightning Clears Safe Zone in Earth's Radiation Belt
  • NOAA: What is Lightning?
  • National Geographic Lightning Simulator
  • Live storm data and sferics for southern England generated by data recorded by a weather station at Newport, Isle of Wight, UK [3]
  • Lightning strikes governed by moving cloud layers - the first theory to fully explain lightning formation and dynamics, New Scientist, 23 March 2008

Image File history File links Commons-logo. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 151 languages. ... HowStuffWorks is a website created by Marshall Brain but now owned by the Convex Group. ...

Jets, sprites & elves

  • Homepage of the Eurosprite campaign, itself part of the CAL (Coupled Atmospheric Layers) research group
  • March 2, 1999, University of Houston: UH Physicists Pursue Lightning-Like Mysteries Quote: "...Red sprites and blue jets are brief but powerful lightning-like flashes that appear at altitudes of 40-100 km (25-60 miles) above thunderstorms..."
  • Ground and Balloon-Borne Observations of Sprites and Jets
  • Barrington-Leigh, C. P., "Elves : Ionospheric Heating By the Electromagnetic Pulses from Lightning (A primer)". Space Science Lab, Berkeley.
  • "Darwin Sprites '97". Space Physics Group, University of Otago.
  • Barrington-Leigh, Christopher, "VLF Research at Palmer Station".
  • Sprites, jets and TLE pictures and articles
In thermodynamics, an adiabatic process or an isocaloric process is a thermodynamic process in which no heat is transferred to or from the working fluid. ... The lapse rate is defined as the negative of the rate of change in an atmospheric variable, usually temperature, with height observed while moving upwards through an atmosphere. ... Solar irradiance spectrum at top of atmosphere. ... A surface weather analysis for the United States on October 21, 2006. ... In Meteorology, ability is a measure of the nothingness at which an object or light can be seen. ... Vorticity is a mathematical concept used in fluid dynamics. ... For other uses, see Wind (disambiguation). ... For other uses, see Condensation (disambiguation). ... For other uses, see Cloud (disambiguation). ... Aerosol pollution over Northern India and Bangladesh - NASA Cloud condensation nuclei or CCNs (also known as cloud seeds) are small particles (typically 0. ... The dew point (or dewpoint) is the temperature which a given parcel of air must be cooled, at constant barometric pressure, for water vapor to condense into water. ... For other uses, see Fog (disambiguation). ... Water vapor or water vapour (see spelling differences), also aqueous vapor, is the gas phase of water. ... Convection in the most general terms refers to the movement of currents within fluids (i. ... In meteorology, convective available potential energy (CAPE) is the amount of energy a parcel of air would have if lifted a certain distance vertically through the atmosphere. ... Convective inhibition (CIN or CINH) is a meteorlogic parameter that measures the amount of energy that will prevent an air parcel from rising from the surface to the level of free convection. ... This article or section is in need of attention from an expert on the subject. ... For other uses, see Temperature (disambiguation). ... The heat index (HI) or humidex is an index that combines air temperature and relative humidity to determine an apparent temperature — how hot it actually feels. ... Heat Index (HI) is an index that combines air temperature and relative humidity to determine an apparent temperature — how hot it actually feels. ... The term humidity is usually taken in daily language to refer to relative humidity. ... The lifted index (LI) is the temperature difference between an air parcel lifted adiabatically and the temperature of the environment at a pressure height in the atmosphere, usually 500 hPa (mb). ... The potential temperature of a parcel of air at pressure is the temperature that the parcel would acquire if adiabatically brought to a standard reference pressure , usually 1 bar. ... Equivalent potential temperature, commonly referred to as Theta-e , is a measure of the instability of air at a given pressure, humidity, and temperature. ... Annual mean sea surface temperature for the World Ocean. ... Wind chill is the apparent temperature felt on the exposed human (or animal) body due to the combination of air temperature and wind speed. ... This article is about pressure in the physical sciences. ... Atmospheric pressure is the pressure at any given point in the Earths atmosphere. ... Density lines and isobars cross in a baroclinic fluid (top). ...

  Results from FactBites:
 
Lightning - Wikipedia, the free encyclopedia (7196 words)
Ground-to-cloud lightning is a lightning discharge between the ground and a cumulonimbus cloud from an upward-moving leader stroke.
Trees are frequent conductors of lightning to the ground (photo of a tree being struck by lightning).
The lightning bolt shape was a symbol of male humans among the Native Americans such as the Apache (a rhombus shape being a symbol for females) in the American Old West.
English Electric Lightning - Wikipedia, the free encyclopedia (1831 words)
The English Electric Lightning (later the BAC Lightning) was a supersonic British fighter aircraft of the Cold War era, particularly remembered for its great speed, and its natural metal exterior that was used throughout much of its service life with the Royal Air Force and the Royal Saudi Air Force.
The Lightning shared a number of innovations first planned for the Miles M.52 including the shock cone and all-flying tailplane, the latter described by Chuck Yeager as the single most significant contribution to the final success of supersonic flight.
Lightnings were slowly phased out of service between 1974 and 1988, although much testing and modification was needed to keep them in air-worthy condition due to the high number of flight hours accumulated.
  More results at FactBites »

 
 

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