Lightning

1.

2.

3.

lightning - молния
[ˈlaɪtnɪŋ]
cloud-to-ground
lightning - молния
[klaʊd-tuː-graʊnd ˈlaɪtnɪŋ]
облако-земля
cloud to cloud
lightning - молния от
облака к облаку
[klaʊd-tuː-klaʊd ˈlaɪtnɪŋ]

4.

intra-cloud lightning
[ˈɪntrɪ-klaʊd ˈlaɪtnɪŋ]
- внутриоблачная
молния
anvil crawler lightning
[ˈænvɪl ˈkrɔːlə ˈlaɪtnɪŋ]
- ленточная молния
ball lightning шаровая молния
[bɔːl ˈlaɪtnɪŋ]

5.

bead lightning –
[biːd ˈlaɪtnɪŋ]
бисерная молния
cloud-to-air lightning –
[klaʊd-tuː-eə ˈlaɪtnɪŋ]
молния облако-воздух
dry lightning - сухая
молния
[draɪ ˈlaɪtnɪŋ]

6.

forked lightning -
[fɔːkt ˈlaɪtnɪŋ]
раздвоенная молния
heat lightning -
[hiːt ˈlaɪtnɪŋ]
зарница
ribbon lightning ленточная молния
[ˈrɪbən ˈlaɪtnɪŋ]

7.

rocket lightning
[ˈrɒkɪt ˈlaɪtnɪŋ]
- ракетная молния
sheet lightning -
[ʃiːt ˈlaɪtnɪŋ]
листовая молния
smooth channel
lightning гладкоканальная
молния
[smuːð ʧænl ˈlaɪtnɪŋ]

8.

staccato lightning -
[stəˈkɑːtəʊ ˈlaɪtnɪŋ]
молния стакатто
superbolts – удары
[superbolts]
молнии
sympathetic lightning
- молния в верхних
слоях атмосферы
[sɪmpəˈθetɪk ˈlaɪtnɪŋ]

9.

upward lightning -
[ˈʌpwəd ˈlaɪtnɪŋ]
молния земля-облако
clear-air lightning высокоразряженная
молния
[klɪə-eə ˈlaɪtnɪŋ]

10.

Lightning

11.

Lightning is a naturally occurring electrostatic discharge during which two
electrically charged regions, both in the atmosphere or with one on the ground,
temporarily equalize themselves, causing the instantaneous release of as much as one
gigajoule of energy. This discharge may produce a wide range of electromagnetic
radiation, from very hot plasma created by the rapid movement of electrons, to
brilliant flashes of visible light in the form of black-body radiation. Lightning causes
thunder, a sound from the shock wave which develops as gases in the vicinity of the
discharge experience a sudden increase in pressure. Lightning occurs commonly
during thunderstorms as well as other types of energetic weather systems, but
volcanic lightning can also occur during volcanic eruptions.
The three main kinds of lightning are distinguished by where they occur: either
inside a single thundercloud, between two different clouds, or between a cloud and
the ground. Many other observational variants are recognized, including "heat
lightning", which can be seen from a great distance but not heard; dry lightning,
which can cause forest fires; and ball lightning, which is rarely observed
scientifically.

12.

The typical cloud-to-ground lightning flash culminates in the formation of an
electrically conducting plasma channel through the air in excess of 5 km tall, from
within the cloud to the ground's surface. The actual discharge is the final stage of a
very complex process. At its peak, a typical thunderstorm produces three or more
strikes to the Earth per minute. Lightning primarily occurs when warm air is mixed
with colder air masses, resulting in atmospheric disturbances necessary for polarizing
the atmosphere.[citation needed] However, it can also occur during dust storms, forest
fires, tornadoes, volcanic eruptions, and even in the cold of winter, where the
lightning is known as thundersnow. Hurricanes typically generate some lightning,
mainly in the rainbands as much as 160 km from the center.
The science of lightning is called fulminology, and the fear of lightning is called
astraphobia.
The best-studied and understood form of lightning is cloud to ground (CG) lightning.
Although more common, intra-cloud (IC) and cloud-to-cloud (CC) flashes are very
difficult to study given there are no "physical" points to monitor inside the clouds.
Also, given the very low probability of lightning striking the same point repeatedly
and consistently, scientific inquiry is difficult even in areas of high CG frequency.

13.

In a process not well understood, a bidirectional channel of ionized air, called a
"leader", is initiated between oppositely-charged regions in a thundercloud. Leaders
are electrically conductive channels of ionized gas that propagate through, or are
otherwise attracted to, regions with a charge opposite of that of the leader tip. The
negative end of the bidirectional leader fills a positive charge region, also called a
well, inside the cloud while the positive end fills a negative charge well. Leaders
often split, forming branches in a tree-like pattern. In addition, negative and some
positive leaders travel in a discontinuous fashion, in a process called "stepping". The
resulting jerky movement of the leaders can be readily observed in slow-motion
videos of lightning flashes.
It is possible for one end of the leader to fill the oppositely-charged well entirely
while the other end is still active. When this happens, the leader end which filled the
well may propagate outside of the thundercloud and result in either a cloud-to-air
flash or a cloud-to-ground flash. In a typical cloud-to-ground flash, a bidirectional
leader initiates between the main negative and lower positive charge regions in a
thundercloud. The weaker positive charge region is filled quickly by the negative
leader which then propagates toward the inductively-charged ground.

14.

Cloud-to-ground lightning

15.

Cloud-to-ground lightning is a lightning discharge between a thundercloud and the
ground. It is initiated by a stepped leader moving down from the cloud, which is met
by a streamer moving up from the ground.
CG is the least common, but best understood of all types of lightning. It is easier to
study scientifically because it terminates on a physical object, namely the Earth, and
lends itself to being measured by instruments on the ground. Of the three primary
types of lightning, it poses the greatest threat to life and property since it terminates
or "strikes" the Earth.
The overall discharge termed a flash, is composed of a number of processes such as
preliminary breakdown, stepped leaders, connecting leaders, return strokes, dart
leaders, and subsequent return strokes. The conductivity of the ground, be it ground,
fresh water or salt water, may impact the lightning discharge rate and thus visible
characteristics.
Positive and negative lightning
Cloud-to-ground lightning is either positive or negative, as defined by the direction
of the conventional electric current between cloud and ground. Most CG lightning is
negative, meaning that a negative charge is transferred to ground and electrons travel
downward along the lightning channel (conventionally the current flows from the
ground to the cloud).

16.

The reverse happens in a positive CG flash, where electrons travel upward along the
lightning channel and a positive charge is transferred to the ground (conventionally
the current flows from the cloud to the ground). Positive lightning is less common
than negative lightning, and on average makes up less than 5% of all lightning
strikes.
There are six different mechanisms theorized to result in the formation of positive
lightning.
Vertical wind shear displacing the upper positive charge region of a thundercloud,
exposing it to the ground below.
The loss of lower charge regions in the dissipating stage of a thunderstorm, leaving
the primary positive charge region.
A complex arrangement of charge regions in a thundercloud, effectively resulting in
an inverted dipole or inverted tripole in which the main negative charge region is
above the main positive charge region instead of beneath it.
An unusually large lower positive charge region in the thundercloud.

17.

Cutoff of an extended negative leader from its origin which creates a new
bidirectional leader in which the positive end strikes the ground, commonly seen in
anvil-crawler spider flashes.
The initiation of a downward positive branch from an IC lightning flash.

18.

Cloud to cloud lightning

19.

Intra-cloud lightning

20.

Lightning discharges may occur between areas of cloud without contacting the
ground. When it occurs between two separate clouds, it is known as cloud-to-cloud or
inter-cloud lightning; when it occurs between areas of differing electric potential
within a single cloud, it is known as intra-cloud lightning. IC lightning is the most
frequently occurring type.
IC lightning most commonly occurs between the upper anvil portion and lower
reaches of a given thunderstorm. This lightning can sometimes be observed at great
distances at night as so-called "sheet lightning". In such instances, the observer may
see only a flash of light without hearing any thunder.
Another term used for cloud–cloud or cloud–cloud–ground lightning is "Anvil
Crawler", due to the habit of charge, typically originating beneath or within the anvil
and scrambling through the upper cloud layers of a thunderstorm, often generating
dramatic multiple branch strokes. These are usually seen as a thunderstorm passes
over the observer or begins to decay. The most vivid crawler behavior occurs in well
developed thunderstorms that feature extensive rear anvil shearing.

21.

Anvil crawler lightning

22.

Ball lightning

23.

Anvil crawler lightning, sometimes called Spider lightning is created when leaders
propagate through horizontally-extensive charge regions in mature thunderstorms,
usually the stratiform regions of mesoscale convective systems. These discharges
usually begin as IC discharges originating within the convective region; the negative
leader end then propagates well into the aforementioned charge regions in the
stratiform area. If the leader becomes too long, it may separate into multiple
bidirectional leaders. When this happens, the positive end of the separated leader
may strike the ground as a positive CG flash or crawl on the underside of the cloud,
creating a spectacular display of lightning crawling across the sky. Ground flashes
produced in this manner tend to transfer high amounts of charge, and this can trigger
upward lightning flashes and upper-atmospheric lightning.
Ball lightning may be an atmospheric electrical phenomenon, the physical nature of
which is still controversial. The term refers to reports of luminous, usually spherical
objects which vary from pea-sized to several meters in diameter. It is sometimes
associated with thunderstorms, but unlike lightning flashes, which last only a
fraction of a second, ball lightning reportedly lasts many seconds. Ball lightning has
been described by eyewitnesses but rarely recorded by meteorologists. Scientific data
on natural ball lightning is scarce owing to its infrequency and unpredictability. The
presumption of its existence is based on reported public sightings, and has therefore
produced somewhat inconsistent findings. Brett Porter, a wildlife ranger, reported
taking a photo in Queensland, Australia in 1987.

24.

Bead lightning

25.

Cloud-to-air lightning

26.

Dry lightning

27.

Bead lightning, also known by the terms pearl lightning, chain lightning,
perlschnurblitz and eclair en chapelet, to name a few is the decaying stage of a
lightning channel in which the luminosity of the channel breaks up into segments.
Nearly every lightning discharge will exhibit beading as the channel cools
immediately after a return stroke, sometimes referred to as the lightning's 'bead-out'
stage. 'Bead lightning' is more properly a stage of a normal lightning discharge rather
than a type of lightning in itself. Beading of a lightning channel is usually a smallscale feature, and therefore is often only apparent when the observer/camera is close
to the lightning.
Cloud-to-air lightning is a lightning flash in which one end of a bidirectional leader
exits the cloud, but does not result in a ground flash. Such flashes can sometimes be
thought of as failed ground flashes. Blue jets and gigantic jets are a form of cloud-toair or cloud-to-ionosphere lightning where a leader is launched from the top of a
thunderstorm.
Dry lightning is used in Australia, Canada and the United States for lightning that
occurs with no precipitation at the surface. This type of lightning is the most common
natural cause of wildfires. Pyrocumulus clouds produce lightning for the same reason
that it is produced by cumulonimbus clouds.

28.

Forked lightning

29.

Heat lightning

30.

Ribbon lightning

31.

Rocket lightning

32.

Sheet lightning

33.

Forked lightning is cloud-to-ground lightning that exhibits branching of its path.
Heat lightning is a lightning flash that appears to produce no discernible thunder
because it occurs too far away for the thunder to be heard. The sound waves dissipate
before they reach the observer.
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.
Rocket lightning 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.
Sheet lightning is cloud-to-cloud lightning that exhibits a diffuse brightening of the
surface of a cloud, caused by the actual discharge path being hidden or too far away.
The lightning itself cannot be seen by the spectator, so it appears as only a flash, or a
sheet of light. The lightning may be too far away to discern individual flashes.

34.

Smooth channel lightning

35.

Staccato lightning

36.

Smooth channel lightning is an informal term referring to a type of cloud-to-ground
lightning strike that has no visible branching and appears like a line with smooth
curves as opposed to the jagged appearance of most lightning channels. They are a
form of positive lightning generally observed in or near the convective regions of
severe thunderstorms in the north central United States. It is theorized that severe
thunderstorms in this region obtain an "inverted tripole" charge structure in which
the main positive charge region is located below the main negative charge region
instead of above it, and as a result these thunderstorms generate predominantly
positive cloud-to-ground lightning. The term "smooth channel lightning" is also
sometimes attributed to upward ground-to-cloud lightning flashes, which are
generally negative flashes initiated by upward positive leaders from tall structures.
Staccato lightning is a cloud-to-ground lightning strike which is a short-duration
stroke that (often but not always) appears as a single very bright flash and often has
considerable branching. These are often found in the visual vault area near the
mesocyclone of rotating thunderstorms and coincides with intensification of
thunderstorm updrafts. A similar cloud-to-cloud strike consisting of a brief flash over
a small area, appearing like a blip, also occurs in a similar area of rotating updrafts.

37.

Superbolts

38.

Sympathetic lightning

39.

Upward lightning

40.

Superbolts are rather loosely defined as strikes with a source energy of more than 100
gigajoule (most lightning strikes come in at around 1 gigajoule). Events of this
magnitude occur about as frequently as one in 240 strikes. They are not categorically
distinct from ordinary lightning strikes, and simply represent the uppermost edge of
a continuum. Contrary to popular misconception, superbolts can be either positively
or negatively charged, and the charge ratio is comparable to that of "ordinary"
lightning.
Sympathetic lightning is the tendency of lightning to be loosely coordinated across
long distances. Discharges can appear in clusters when viewed from space.
Upward lightning or ground-to-cloud lightning is a lightning flash which originates
from the top of a grounded object and propagates upward from this point. This type
of lightning can be triggered by a preceding lightning flash, or it may initiate entirely
on its own. The former is generally found in regions where spider lightning occurs,
and may involve multiple grounded objects simultaneously. The latter usually occurs
during the cold season and may be the dominant lightning type in thundersnow
events.

41.

Clear-air lightning

42.

Clear-air lightning describes lightning that occurs with no apparent cloud close
enough to have produced it. In the U.S. and Canadian Rockies, a thunderstorm can be
in an adjacent valley and not observable from the valley where the lightning bolt
strikes, either visually or audibly. European and Asian mountainous areas experience
similar events. Also in areas such as sounds, large lakes or open plains, when the
storm cell is on the near horizon (within 26 km or 16 mi) there may be some distant
activity, a strike can occur and as the storm is so far away, the strike is referred to as a
bolt from the blue. These flashes usually begin as normal IC lightning flashes before
the negative leader exits the cloud and strikes the ground a considerable distance
away. Positive clear-air strikes can occur in highly sheared environments where the
upper positive charge region becomes horizontally displaced from the precipitation
area.