How many types of lightning are there really? It turns out that there are more than ten types of them, and the most interesting of them are given in this article. Naturally, here are not only bare facts, but also real photographs of real lightning.

So, the types of lightning will be considered in order, from the most common linear lightning to the rarest sprite lightning. Each type of lightning is given one or more photos that help you understand what such lightning actually is.

L frost lightning (cloud-ground)

How to get such lightning? Yes, it’s very simple - all that is required is a couple of hundred cubic kilometers of air, a height sufficient for lightning to form and a powerful heat engine - well, for example, the Earth. Ready? Now let's take the air and gradually begin to heat it. When it begins to rise, with each meter of rise the heated air cools, gradually becoming colder and colder. The water condenses into increasingly larger droplets, forming thunderclouds. Remember those dark clouds above the horizon, at the sight of which the birds fall silent and the trees stop rustling? So, these are thunderclouds that give birth to lightning and thunder.

Scientists believe that lightning is formed as a result of the distribution of electrons in the cloud, usually the top of the cloud is positively charged, and the outer part is negatively charged. The result is a very powerful capacitor, which can be discharged from time to time as a result of the abrupt transformation of ordinary air into plasma (this occurs due to the increasingly strong ionization of atmospheric layers close to thunderclouds). Plasma forms unique channels, which, when connected to the ground, serve as an excellent conductor for electricity. Clouds are constantly discharged through these channels, and we see external manifestations of these atmospheric phenomena in the form of lightning.

By the way, the air temperature at the place where the charge (lightning) passes reaches 30 thousand degrees, and the speed of lightning propagation is 200 thousand kilometers per hour. In general, a few lightning strikes were enough to supply electricity to a small city for several months.

And such lightning does happen. They are formed as a result of the accumulation of electrostatic charge at the top of the tallest object on earth, which makes it very “attractive” to lightning. Such lightning is formed as a result of the “breaking through” of the air gap between the top of a charged object and the bottom of a thundercloud.

The higher the object, the more likely it is to be struck by lightning. So what they say is true - you shouldn’t hide from the rain under tall trees.

Yes, individual clouds can also “exchange” lightning, striking each other with electric charges. It's simple - since the upper part of the cloud is positively charged and the lower part is negatively charged, nearby thunderclouds can shoot electric charges at each other.

A fairly common occurrence is lightning that pierces one cloud, and a much rarer occurrence is lightning that travels from one cloud to another.

This lightning does not strike the ground, it spreads horizontally across the sky. Sometimes such lightning can spread across a clear sky, coming from a single thundercloud. Such lightning is very powerful and very dangerous.

This lightning looks like several lightning bolts running parallel to each other. There is no mystery in their formation - if a strong wind blows, it can expand the plasma channels that we wrote about above, and as a result, differentiated lightning like this is formed.

This is a very, very rare lightning, it exists, yes, but how it is formed is still anyone's guess. Scientists suggest that dotted lightning is formed as a result of the rapid cooling of some parts of the lightning track, which turns ordinary lightning into dotted lightning. As we can see, this explanation clearly needs to be refined and supplemented.

So far we have talked only about what happens below the clouds, or at their level. But it turns out that some types of lightning occur above the clouds. They have been known since the advent of jet aircraft, but these lightning strikes were photographed and filmed only in 1994. They look most like jellyfish, right? The height of the formation of such lightning is about 100 kilometers. It is not yet very clear what they are.

Here are photos and even a video of the unique lightning sprites. Very beautiful.

Some people claim that ball lightning does not exist. Others post videos of ball lightning on YouTube and prove that it is all real. In general, scientists are not yet firmly convinced of the existence of ball lightning, and the most famous evidence of their reality is a photo taken by a Japanese student.

This, in principle, is not lightning, but simply the phenomenon of a glow discharge at the end of various sharp objects. St. Elmo's Fire was known in ancient times, and is now described in detail and captured on film.

These are very beautiful lightning that appear during a volcanic eruption. Probably, a gas-dust charged dome that penetrates several layers of the atmosphere at once causes disturbances, since it itself carries a fairly significant charge. It all looks very beautiful, but creepy. Scientists do not yet know exactly why such lightning is formed, and there are several theories, one of which is outlined above.

Here are some interesting facts about lightning that are not often published:

* Typical lightning lasts about a quarter of a second and consists of 3-4 discharges.

* An average thunderstorm travels at 40 km per hour.

* There are 1,800 thunderstorms in the world right now.

* The American Empire State Building is struck by lightning on average 23 times a year.

* Airplanes are struck by lightning on average once every 5-10 thousand flight hours.

* The chance of being killed by lightning is 1 in 2,000,000. Each of us has the same chances of dying from falling out of bed.

* The probability of seeing ball lightning at least once in your life is 1 in 10,000.

* People struck by lightning were considered marked by God. And if they died, they supposedly went straight to heaven. In ancient times, victims of lightning were buried at the place of death.

What should you do when lightning approaches?

In the house

* Close all windows and doors.
* Unplug all electrical appliances. Avoid touching items, including phones, during thunderstorms.
*Keep away from bathtubs, faucets and sinks as metal pipes can conduct electricity.
* If ball lightning enters the room, try to get out quickly and close the door on the other side. If you fail, at least freeze in place.

On the street

* Try to go into a house or car. Do not touch metal parts in the car. The car should not be parked under a tree: suddenly lightning will strike it and the tree will fall right on you.
* If there is no shelter, go out into the open and bend over and press yourself to the ground. But you can’t just lie down!
* In the forest it is better to hide under low bushes. NEVER stand under a freestanding tree.
* Avoid towers, fences, tall trees, telephone and electrical wires, and bus stops.
* Stay away from bicycles, barbecues, and other metal objects.
* Do not go near lakes, rivers or other bodies of water.
* Remove anything metallic from yourself.
* Don't stand in the crowd.
* If you are in an open area and suddenly feel your hair stand on end, or hear strange noises coming from objects (that means lightning is about to strike!), bend forward with your hands on your knees (not on the ground). The legs should be together, the heels pressed against each other (if the legs are not touching, the shock will pass through the body).
* If a thunderstorm finds you in a boat and you no longer have time to swim to the shore, bend down to the bottom of the boat, put your legs together and cover your head and ears.

Lightning is a giant electrical spark. When it hits buildings, it causes fires, splits large trees, and infects people. At any given time, more than 2,000 thunderstorms flash lightning in different parts of the Earth. Every second, about 50 lightning strikes the surface of the earth, and on average, every square kilometer of it is struck by lightning six times a year

Lightning is a giant electrical spark discharge in the atmosphere, usually occurring during a thunderstorm, resulting in a bright flash of light and accompanying thunder. Lightning has also been recorded on Venus, Jupiter, Saturn and Uranus. The current in a lightning discharge reaches 10-20 thousand amperes, so few people manage to survive after being struck by lightning.

The surface of the globe is more electrically conductive than air. However, the electrical conductivity of air increases with altitude. The air is usually positively charged, and the Earth is negatively charged. Water droplets in a thundercloud are charged due to the absorption of charged tiny particles (ions) in the air. A drop falling from a cloud has a negative charge at the top and a positive charge at the bottom. Falling drops mostly absorb negatively charged particles and acquire a negative charge. In the process of swirling in the cloud, water droplets are sprayed, with small drops flying with a negative charge, and large drops flying with a positive charge. The same thing happens with ice crystals at the top of the cloud. When they split, small ice particles acquire a positive charge and are carried away by ascending currents to the upper part of the cloud, and large, negatively charged particles fall to the lower part of the cloud. As a result of the separation of charges, electric fields are created in the thundercloud and in the surrounding space. With the accumulation of large volumetric charges in a thundercloud, spark discharges (lightning) occur between individual parts of the cloud or between the cloud and the earth's surface. Lightning discharges vary in appearance. The most commonly observed is linear branched lightning, sometimes ball lightning, etc.

Lightning is of great interest not only as a peculiar natural phenomenon. It makes it possible to observe an electrical discharge in a gaseous medium at a voltage of several hundred million volts and a distance between electrodes of several kilometers.

In 1750, B. Franklin proposed to the Royal Society of London to conduct an experiment with an iron rod mounted on an insulating base and mounted on a high tower. He expected that when a thundercloud approached the tower, a charge of the opposite sign would be concentrated at the upper end of the initially neutral rod, and a charge of the same sign as at the base of the cloud would be concentrated at the lower end. If the electric field strength during a lightning discharge increases sufficiently, the charge from the upper end of the rod will partially flow into the air, and the rod will acquire a charge of the same sign as the base of the cloud.

The experiment proposed by Franklin was not carried out in England, but it was carried out in 1752 in Marly near Paris by the French physicist Jean d'Alembert. He used an iron rod 12 m long inserted into a glass bottle (which served as an insulator), but did not place it on the tower. May 10 his assistant reported that when a thundercloud was over the bar, sparks occurred when a grounded wire was brought near it.

Franklin himself, unaware of the successful experiment carried out in France, in June of the same year conducted his famous experiment with a kite and observed electric sparks at the end of a wire tied to it. The following year, while studying the charges collected from the rod, Franklin determined that the bases of thunderclouds were usually negatively charged.

More detailed studies of lightning became possible at the end of the 19th century. thanks to the improvement of photographic methods, especially after the invention of an apparatus with rotating lenses, which made it possible to record rapidly developing processes. This type of camera was widely used in the study of spark discharges. It has been found that there are several types of lightning, with the most common being line, plane (in-cloud) and ball (air discharges).

Linear lightning has a length of 2-4 km and has a large current. It is formed when the electric field strength reaches a critical value and the ionization process occurs. The latter is initially created by free electrons, always present in the air. Under the influence of an electric field, electrons acquire high speeds and on their way to the Earth, colliding with air atoms, they split and ionize them. Ionization occurs in a narrow channel, which becomes conductive. The air is heating up. Through a channel of heated air, the charge from the cloud flows to the earth's surface at a speed of more than 150 km/h. This is the first stage of the process. When a charge reaches the Earth's surface between the cloud and the ground, a conductive channel is created through which charges move towards each other: positive charges from the Earth's surface and negative charges accumulated in the cloud. Linear lightning is accompanied by a strong rolling sound - thunder, reminiscent of an explosion. The sound appears as a result of the rapid heating and expansion of air in the channel, and then its equally rapid cooling and compression.

Flat lightning occurs within a thundercloud and appears as flashes of diffuse light.

Ball lightning consists of a luminous mass in the shape of a ball, somewhat smaller than a soccer ball, moving at low speed in the direction of the wind. They burst with a big bang or disappear without a trace. Ball lightning appears after linear lightning. It often enters rooms through open doors and windows. The nature of ball lightning is not yet known. Air discharges of ball lightning, starting from a thundercloud, are often directed horizontally and do not reach the earth's surface.

To protect against lightning, lightning rods are created, with the help of which the lightning charge is carried into the ground along a specially prepared safe path.

A lightning discharge usually consists of three or more repeated strikes - pulses following the same path. The intervals between successive pulses are very short, from 1/100 to 1/10 s (this is what causes lightning to flicker). In general, the flash lasts about a second or less. A typical lightning development process can be described as follows. First, a weakly luminous leader discharge rushes from above to the earth's surface. When he reaches it, a brightly glowing return, or main, discharge passes from the ground up through the channel laid by the leader.

The leading discharge, as a rule, moves in a zigzag manner. The speed of its spread ranges from one hundred to several hundred kilometers per second. On its way, it ionizes air molecules, creating a channel with increased conductivity, through which the reverse discharge moves upward at a speed approximately one hundred times greater than that of the leading discharge. The size of the channel is difficult to determine, but the diameter of the leading discharge is estimated at 1–10 m, and the diameter of the return discharge is several centimeters.

Lightning discharges create radio interference by emitting radio waves in a wide range - from 30 kHz to ultra-low frequencies. The greatest emission of radio waves is probably in the range from 5 to 10 kHz. Such low-frequency radio interference is “concentrated” in the space between the lower boundary of the ionosphere and the earth’s surface and can spread to distances of thousands of kilometers from the source.

Lightning: the giver of life and the engine of evolution. In 1953, biochemists S. Miller (Stanley Miller) and G. Urey (Harold Urey) showed that one of the "building blocks" of life - amino acids - can be obtained by passing an electric discharge through water in which the gases of the "primordial" atmosphere of the Earth are dissolved ( methane, ammonia and hydrogen). 50 years later, other researchers repeated these experiments and obtained the same results. Thus, the scientific theory of the origin of life on Earth assigns a fundamental role to lightning strikes. When short current pulses are passed through bacteria, pores appear in their shell (membrane), through which DNA fragments of other bacteria can pass in, triggering one of the mechanisms of evolution.

How to protect yourself from lightning using a water jet and a laser. Recently, a fundamentally new method of combating lightning was proposed. A lightning rod will be created from... a jet of liquid that will be shot from the ground directly into thunderclouds. Lightning liquid is a saline solution to which liquid polymers are added: the salt is intended to increase electrical conductivity, and the polymer prevents the jet from “breaking up” into individual droplets. The diameter of the jet will be about a centimeter, and the maximum height will be 300 meters. When the liquid lightning rod is finalized, it will be equipped with sports and children's playgrounds, where the fountain will turn on automatically when the electric field strength becomes high enough and the probability of a lightning strike is maximum. A charge will flow down a stream of liquid from a thundercloud, making lightning safe for others. Similar protection against lightning discharge can be done using a laser, the beam of which, ionizing the air, will create a channel for an electrical discharge away from crowds of people.

Can lightning lead us astray? Yes, if you use a compass. In the famous novel by G. Melville "Moby Dick" exactly such a case is described when a lightning discharge, which created a strong magnetic field, remagnetized the compass needle. However, the captain of the ship took a sewing needle, hit it to magnetize it, and replaced it with the damaged compass needle.

Can you be struck by lightning inside a house or airplane? Unfortunately yes! Lightning current can enter a house through a telephone wire from a nearby pole. Therefore, during a thunderstorm, try not to use a regular phone. It is believed that talking on a radiotelephone or mobile phone is safer. During a thunderstorm, you should not touch the central heating and water pipes that connect the house to the ground. For the same reasons, experts advise turning off all electrical appliances during a thunderstorm, including computers and televisions.

As for airplanes, generally speaking, they try to fly around areas with thunderstorm activity. And yet, on average, one of the planes is struck by lightning once a year. Its current cannot affect passengers; it flows down the outer surface of the aircraft, but it can damage radio communications, navigation equipment and electronics.

Into the key, emitting a sheaf of sparks. Since then, scientists have begun to study lightning in detail. This amazing natural phenomenon can be extremely dangerous, causing serious damage to power lines and other tall buildings. The main reason for the occurrence of lightning lies in the collision of ions (impact ionization). The electric field of a cloud has a very high intensity. In such a field, free electrons receive enormous acceleration. When they collide with atoms, they ionize them. Ultimately, a flow of fast electrons arises. Impact ionization forms a plasma channel through which the main current pulse passes. An electrical discharge occurs, which we observe in the form of lightning. The length of such a discharge can reach several kilometers and last up to several seconds. Lightning is always accompanied by a bright flash of light and thunder. Very often, lightning occurs during a thunderstorm, but there are exceptions. One of the most unexplored natural phenomena associated with electrical discharges by scientists is ball lightning. What is known is that it occurs suddenly and can cause significant damage. So why is lightning so bright? The electric current from a lightning strike can reach 100,000 Amperes. This releases enormous energy (about a billion Joules). The temperature of the main channel reaches almost 10,000 degrees. These characteristics give rise to the bright light that can be observed during a lightning strike. After such a powerful electrical discharge, there is a pause that can last from 10 to 50 seconds. During this time, the main channel almost goes out, the temperature in it drops to 700 degrees. Scientists have found that the bright glow and heating of the plasma channel propagate from the bottom up, and the pauses between the glows are only tens of fractions of seconds. That is why a person perceives several powerful impulses as a single bright flash of lightning.

Video on the topic

Almost all people are afraid of a thunderstorm, or, at least, are afraid of it and prefer to wait it out in a safe place - and this is the right approach. The sky gets dark and overcast, the sun disappears, but thunder rumbles and lightning flashes - nature goes berserk, and this can be dangerous.

A thunderstorm is a phenomenon whose name alone makes a lot clear. When everything around is illuminated by flashes, accompanied by thunderclaps, which, as a rule, are followed by a strong one, questions inevitably arise: “What is happening there?”, “Where does lightning come from and does it sparkle so brightly?” The nature of lightning is electric. Thunderclouds are real giants. They seem huge, but from there it is still not clear how big they are. The height of a medium-sized thundercloud is several kilometers. They are not at all as calm inside as they may seem on the outside. The air currents in the clouds move chaotically in all directions, everything there is “seething and seething.” The temperature in the cloud is also not evenly distributed. At its very top it is usually very cold, about -40 degrees Celsius. Water, which is the main component of a thundercloud, at this temperature, of course, freezes. Small pieces of ice are formed, which rush around inside the cloud in the same way as ordinary drops of water: with great speed and very randomly. Ice floes constantly collide with each other and with water, they are charged with electricity and are destroyed. The heaviest ones move closer to the bottom of the cloud and usually melt there, sometimes falling in the form of hail. Quite quickly, the opposite electrical charges in the cloud are concentrated in different areas: positive ones predominate at the top, and negative ones at the bottom, but the seething inside does not stop. Sometimes powerful currents arise when many positive and negative particles collide simultaneously. Thunderclouds are very large formations, and when two powerful vortices, charged oppositely, collide, a very strong electrical discharge is formed. This is lightning. It sparkles dazzlingly, instantly heating the air around it to a very high temperature so that it explodes. Thunder is this very explosion of an air mass heated by an electric discharge. The electric discharge itself can be directed either from one part of the cloud to another, or from them to the ground. If lightning strikes objects located on the ground, it easily splits even large stones, and everything that burns ignites from its strike. Lightning is attracted to everything that rises above the rest of the landscape. Therefore, to protect houses, people came up with lightning rods: these are metal poles that conduct current into the ground and in this way neutralize it. But if a thunderstorm starts and you are not at home, do not hide under tall objects, such as trees. Because there is a high probability that lightning will strike one of them.

Thunderstorm lightning is a powerful and majestic natural phenomenon, capable of inspiring awe with its power. In ancient times, lightning was considered a manifestation of supernatural forces, evidence of divine wrath. However, with the development of science, it became clear to humanity that there is nothing mysterious or supernatural in the nature of lightning. Their occurrence and properties are subject to completely understandable physical laws.

In essence, it is simply a very powerful electrical discharge. It is similar to what sometimes occurs if you actively comb clean, dry hair with a plastic comb or rub an ebonite stick with a woolen cloth. In both cases, static electricity accumulates, which is discharged in the form of a bright spark and crackling sound. Only in the case of a thundercloud, instead of a weak crack, a thunderclap is heard.

Lightning occurs when thunderclouds are electrified, creating a powerful electric field inside the cloud. But a logical question may arise: does electrification of clouds occur at all? After all, there are no solid objects in them that could rub and collide with each other and thus create electrical voltage.

In reality, everything is not as difficult as it seems. A thundercloud is simply a huge amount of steam, the upper part of which is at an altitude of 6-7 km, and the lower part does not exceed 0.5-1 km above. But at an altitude of more than 3 km from the surface, the air temperature is always below zero, so the steam inside the cloud turns into small pieces of ice. And these pieces of ice are in constant motion due to air currents inside the cloud. The smaller the pieces of ice, the lighter they are, and when they fall into the ascending currents of heated air rising from the surface, they also move to the upper layers of the cloud.

On their way up, these small pieces of ice collide with larger ones, and each collision causes an electrification. In this case, small pieces of ice are charged positively, and large ones - negatively. As a result of such movements, a large number of positively charged pieces of ice accumulate in the upper part of the thundercloud, while large, heavy and negatively charged pieces of ice remain in the lower layer. In other words, the upper edge of a thundercloud turns out to be positively charged, and the lower edge is negatively charged.

And when large oppositely charged areas are quite close to each other, a luminous plasma channel appears between them, along which charged particles rush. As a result, a lightning discharge occurs, which can be observed in the form of a bright light zigzag. The electric field of a cloud has enormous intensity and during a lightning discharge enormous energy of the order of a billion joules is released.

A lightning discharge can occur inside a thundercloud itself, between two adjacent clouds, or between a cloud and the earth's surface. In the latter case, the power of electrical discharges between the ground and the clouds is incomparably greater, and the force of electrical energy passing through the atmosphere can create a current of up to 10,000 amperes. For comparison, it is worth remembering that the current strength in ordinary home electrical wiring does not exceed 6 amperes.

Lightning usually has a zigzag shape because charged particles flying towards the ground collide with air particles and change the direction of their movement. Lightning can also be linear or branched. One of the rarest and least studied forms of lightning is ball lightning, which has the shape of a luminous ball and can move parallel to the surface of the earth.

One of the first pieces of evidence about what lightning was was a photograph of the area where the flash was visible, taken with the shutter closed. The picture shows that lightning is a discharge passing along the same path.

Primary lightning strike

The process of lightning formation itself can be divided into the primary strike and all the others. This is justified by the fact that the primary lightning strike, unlike others, creates a path (channel) for an electrical discharge. This happens as follows. A powerful negative charge accumulates at the bottom of the cloud. The surface of the earth has a positive charge. Thus, the electrons lying at the bottom of the cloud, under the influence of the potential difference, rush down.

This process does not yet produce any flash of light. At some point, they stop for a few microseconds, and then continue moving in the other direction, making their way to. Each such step with a stop forms a step structure. When electrons reach the earth's surface, a channel free for the passage of electrical charges is formed, through which the remaining electrons rush down in a huge stream.

Electrons located near the surface of the earth are the first to leave the channel, forming a positively charged area behind them. Nearby electrons rush to this place. Thus, all the negative electrical charge leaves the cloud, forming a powerful electrical flow directed. It is at this moment that you can see a flash of light, and after it you can hear thunder.

Repeated lightning strikes

After the initial impact has already created a channel for the passage of electrons, the second impact follows the same path. This is due to the fact that electrons during the primary impact ionize the air around them, so a conducting channel is already provided for secondary electrons. Thus, secondary and subsequent lightning strikes occur without pauses and stops characteristic of the primary strike. There is often one or two strikes, but it is not uncommon to see it strike five or six times in the same place.

It happens that the leading branch of lightning begins to branch. This is possible if the electrons of the primary channel take different paths. In this case, if one of the branches reaches the ground much earlier than the other, then the first one makes its way up and reaches the beginning of the second branch. At this moment, the main branch empties the non-main branch, and the observer gets the impression that it is the second branch that hits the ground, and not the first.

As a rule, somewhere around a hundred meters from the soil, the process of electron penetration becomes somewhat more complicated. For example, if there is some tall or pointed object at the point of impact, then due to the formation of a powerful electric field, the discharge begins to rise from this very object, without waiting for the electrons to strike. Thus, the electrons do not reach the surface of the earth, but the counter discharge.

No matter how much science explains the essence of atmospheric electricity, people still flinch when lightning strikes and involuntarily shrink in anticipation of the clap of thunder. Obviously, in most people, the memory of distant ancestors speaks, trying to find at least some kind of protection from heavenly fire.

There is, of course, nothing in atmospheric electricity, but this does not make lightning and the subsequent peals of thunder look any less impressive and menacing. So what exactly is lightning?

As you know from a school physics course, all objects have a very definite electric charge. The collision of charged particles with each other leads to the creation of large areas of positive and negative charges. When such areas are close enough to each other, a breakdown occurs and charged particles rush into the created channel. People perceive this breakdown as a lightning strike.

If lightning is more powerful, then why is it followed by a terrifying roar, reminiscent of artillery cannonade? After all, the same one convinces people that electric current cannot be seen, heard or otherwise detected, with the exception of special devices.

As it turns out, the whole point is in the air, or rather, in its properties. The fact is that, being, in fact, an insulator, at the moment of breakdown it heats up to a temperature of about 30,000°C. Moreover, the rate of heating and, accordingly, expansion of the air environment expands explosively, which leads to the appearance of a shock wave, which the human ear perceives as roar or thunder.

Therefore, lightning and thunder are inseparable, since thunder is the result of lightning. The talk that there is supposedly lightning without thunder and vice versa is groundless.

On the other hand, there are quite a lot of inexplicable things associated with lightning and their manifestations. Such types of lightning as linear, cord, rope, tape are quite well known and relatively well studied. In turn, they are united and branched. The most mysterious and so far unexplored lightning is ball lightning. It is associated with the largest number of oddities and mysteries, both documented and unproven.

It has been repeatedly noted by many eyewitnesses that lightning flickers. The fact is that lightning consists of many successive discharges lasting only a few tens of millionths of a second. This creates the flickering effect.

Lightning discharges occur between individual thunderclouds, between a cloud and the ground, and sometimes, for unknown reasons, the discharge goes vertically into the sky.

As for lightning emanating from clouds to the ground, there are two known types: positive and negative. Moreover, according to scientists, it is positive discharges, as they are more powerful, that lead to fires.

We have all seen bright flashes in the sky when it rains. These are electrical charges passing between a thundercloud and the ground. Such charges are called lightning. But they can be formed only under certain conditions.

Inside thunderclouds, air masses move at tremendous speed. They involve water particles located in the cloud in movement. When air masses rub against water droplets, static electric charges arise. Scientists have found that the top of a thundercloud is charged with positive charges, and in its lower part there is an accumulation of negatively charged particles. The earth always has a positive charge. Negatively charged cloud particles want to rush towards the positively charged ground. But this does not happen all the time, since the earth's surface and the cloud are separated by a large layer of air, which isolates these charges from each other. Air can separate charges only until they reach a certain power. When sufficient power accumulates in a thundercloud, negatively charged particles rush to the ground, forming huge sparks in the form of lightning.

When lightning strikes the ground, we only have time to notice one flash. In fact, about a dozen lightning strikes occur in this visible flash. Negatively charged particles fly towards the ground so quickly that several lightning bolts are perceived as one.

As you know, lightning strikes the highest places. This happens because the positive charge of the earth's surface always accumulates at higher elevations. Therefore, the first lightning strikes the tallest buildings or trees, which are located alone on the plain.

Lightning discharges are accompanied by the release of enormous heat. The temperature in lightning reaches 16 thousand degrees. Therefore, when lightning strikes a beach, the sand on its surface sinteres, forming glass.

We often think that electricity is something that is generated only in power plants, and certainly not in the fibrous masses of water clouds, which are so rarefied that you can easily stick your hand into them. However, there is electricity in the clouds, just as there is even in the human body.

The nature of electricity

All bodies are made of atoms - from clouds and trees to the human body. Every atom has a nucleus containing positively charged protons and neutral neutrons. The exception is the simplest hydrogen atom, in the nucleus of which there is no neutron, but only one proton.

Negatively charged electrons circulate around the nucleus. Positive and negative charges attract each other, so electrons revolve around the nucleus of an atom, like bees around a sweet pie. The attraction between protons and electrons is due to electromagnetic forces. Therefore, electricity is present everywhere we look. As we see, it is also contained in atoms.

Under normal conditions, the positive and negative charges of each atom balance each other, so bodies consisting of atoms usually do not carry any net charge - neither positive nor negative. As a result, contact with other objects does not cause an electrical discharge. But sometimes the balance of electrical charges in bodies can be disrupted. You may experience this yourself while at home on a cold winter day. The house is very dry and hot. You, shuffling with your bare feet, walk around the palace. Unbeknownst to you, some of the electrons from your soles transferred to the atoms of the carpet.

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Now you are carrying an electrical charge because the number of protons and electrons in your atoms is no longer balanced. Now try to grab the metal door handle. A spark will jump between you and her and you will feel an electric shock. What has happened is that your body, which does not have enough electrons to achieve electrical balance, seeks to restore balance through the forces of electromagnetic attraction. And it is restored. Between the hand and the door handle there is a flow of electrons directed towards the hand. If the room was dark, you would see sparks. Light is visible because electrons, when they jump, emit quanta of light. If the room is quiet, you will hear a slight crackling sound.

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Electricity surrounds us everywhere and is contained in all bodies. Clouds in this sense are no exception. Against the background of the blue sky they look very harmless. But just like you in the room, they can carry an electrical charge. If so, beware! When the cloud restores the electrical balance within itself, a whole fireworks display breaks out.

How does lightning appear?

Here's what happens: powerful air currents constantly circulate in a dark, huge thundercloud, pushing various particles together - grains of ocean salt, dust, and so on. Just as your soles, when rubbed against a carpet, are freed from electrons, particles in a cloud, when they collide, are freed from electrons, which jump to other particles. This is how charge redistribution occurs. Some particles that have lost their electrons have a positive charge, while others that have taken on extra electrons now have a negative charge.

Lightning 1882
(c) Photographer: William N. Jennings, c. 1882

The electrical nature of lightning was revealed in the research of the American physicist B. Franklin, on whose idea an experiment was carried out to extract electricity from a thundercloud. Franklin's experience in elucidating the electrical nature of lightning is widely known. In 1750, he published a work that described an experiment using a kite launched into a thunderstorm. Franklin's experience was described in the work of Joseph Priestley.

Physical properties of lightning

The average length of lightning is 2.5 km, some discharges extend up to 20 km in the atmosphere.

Lightning Formation

Most often, lightning occurs in cumulonimbus clouds, then they are called thunderstorms; Lightning sometimes forms in nimbostratus clouds, as well as during volcanic eruptions, tornadoes and dust storms.

Typically observed are linear lightning, which belongs to the so-called electrodeless discharges, since they begin (and end) in accumulations of charged particles. This determines their some still unexplained properties that distinguish lightning from discharges between electrodes. Thus, lightning does not occur shorter than several hundred meters; they arise in electric fields much weaker than the fields during interelectrode discharges; The collection of charges carried by lightning occurs in thousandths of a second from billions of small particles, well isolated from each other, located in a volume of several km³. The most studied process of lightning development in thunderclouds, while lightning can occur in the clouds themselves - intracloud lightning, or they can hit the ground - ground lightning. For lightning to occur, it is necessary that in a relatively small (but not less than a certain critical) volume of the cloud an electric field (see atmospheric electricity) with a strength sufficient to initiate an electrical discharge (~ 1 MV/m) must be formed, and in a significant part of the cloud there would be field with an average strength sufficient to maintain the started discharge (~ 0.1-0.2 MV/m). In lightning, the electrical energy of the cloud is converted into heat, light and sound.

Ground lightning

The development process of ground lightning consists of several stages. At the first stage, in the zone where the electric field reaches a critical value, impact ionization begins, created initially by free charges, always present in small quantities in the air, which, under the influence of the electric field, acquire significant speeds towards the ground and, colliding with the molecules that make up air, ionize them.

According to more modern concepts, ionization of the atmosphere for the passage of a discharge occurs under the influence of high-energy cosmic radiation - particles with energies of 10 12 -10 15 eV, forming a wide air shower (EAS) with a decrease in the breakdown voltage of the air by an order of magnitude from that under normal conditions.

According to one hypothesis, the particles trigger a process called runaway breakdown. Thus, electron avalanches arise, turning into threads of electrical discharges - streamers, which are highly conductive channels that, merging, give rise to a bright thermally ionized channel with high conductivity - stepped lightning leader.

The movement of the leader to the earth's surface occurs steps several tens of meters at a speed of ~ 50,000 kilometers per second, after which its movement stops for several tens of microseconds, and the glow greatly weakens; then, in the subsequent stage, the leader again advances several tens of meters. A bright glow covers all the steps passed; then a stop and weakening of the glow follows again. These processes are repeated as the leader moves to the surface of the earth at an average speed of 200,000 meters per second.

As the leader moves toward the ground, the field strength at its end increases and, under its action, objects are thrown out from objects protruding on the surface of the Earth. response streamer connecting to the leader. This feature of lightning is used to create a lightning conductor.

In the final stage, the channel ionized by the leader follows back(from bottom to top), or main, lightning discharge, characterized by currents from tens to hundreds of thousands of amperes, brightness, noticeably exceeding the brightness of the leader, and a high speed of advancement, initially reaching up to ~ 100,000 kilometers per second, and at the end decreasing to ~ 10,000 kilometers per second. The channel temperature during the main discharge can exceed 2000-3000 °C. The length of the lightning channel can be from 1 to 10 km, the diameter can be several centimeters. After the passage of the current pulse, the ionization of the channel and its glow weaken. In the final stage, the lightning current can last hundredths and even tenths of a second, reaching hundreds and thousands of amperes. Such lightning is called prolonged lightning and most often causes fires. But the ground is not charged, so it is generally accepted that a lightning discharge occurs from the cloud towards the ground (from top to bottom).

The main discharge often discharges only part of the cloud. Charges located at high altitudes can give rise to a new (swept) leader moving continuously at speeds of thousands of kilometers per second. The brightness of its glow is close to the brightness of the stepped leader. When the swept leader reaches the surface of the earth, a second main strike follows, similar to the first. Typically, lightning includes several repeated discharges, but their number can reach several dozen. The duration of multiple lightning can exceed 1 second. The displacement of the channel of multiple lightning by the wind creates the so-called ribbon lightning - a luminous strip.

Intracloud lightning

Intracloud lightning over Toulouse, France. 2006

Intracloud lightning usually includes only leader stages; their length ranges from 1 to 150 km. The proportion of intracloud lightning increases as it moves toward the equator, changing from 0.5 in temperate latitudes to 0.9 in the equatorial zone. The passage of lightning is accompanied by changes in electric and magnetic fields and radio emissions, the so-called atmospherics.

Flight from Kolkata to Mumbai.

The probability of a ground object being struck by lightning increases as its height increases and with an increase in the electrical conductivity of the soil on the surface or at some depth (the action of a lightning rod is based on these factors). If there is an electric field in the cloud that is sufficient to maintain a discharge, but not sufficient to cause it to occur, a long metal cable or an airplane can act as the lightning initiator - especially if it is highly electrically charged. In this way, lightning is sometimes “provoked” in nimbostratus and powerful cumulus clouds.

Lightning in the upper atmosphere

In 1989, a special type of lightning was discovered - elves, lightning in the upper atmosphere. In 1995, another type of lightning in the upper atmosphere was discovered - jets.

Elves

Jets

Jets They are blue cone tubes. The height of the jets can reach 40-70 km (the lower limit of the ionosphere), jets live relatively longer than elves.

Sprites

Sprites are difficult to distinguish, but they appear in almost any thunderstorm at an altitude of 55 to 130 kilometers (the altitude of formation of “ordinary” lightning is no more than 16 kilometers). This is a kind of lightning striking upward from a cloud. This phenomenon was first recorded in 1989 by accident. Currently, very little is known about the physical nature of sprites.

Interaction of lightning with the surface of the earth and objects located on it

Global lightning strike frequency (scale shows number of strikes per year per square kilometer)

Early estimates put the frequency of lightning strikes on Earth at 100 times per second. Current data from satellites, which can detect lightning in areas where there is no ground observation, puts the frequency at an average of 44 ± 5 ​​times per second, which equates to approximately 1.4 billion lightning strikes per year. 75% of this lightning strikes between or within clouds, and 25% strikes the ground.

The most powerful lightning strikes cause the birth of fulgurites.

Shock wave from lightning

A lightning discharge is an electrical explosion and is similar in some aspects to detonation. It causes a shock wave that is dangerous in the immediate vicinity. A shock wave from a sufficiently powerful lightning discharge at distances of up to several meters can cause destruction, break trees, injure and concuss people even without direct electric shock. For example, with a current rise rate of 30 thousand amperes per 0.1 millisecond and a channel diameter of 10 cm, the following shock wave pressures can be observed:

• at a distance from the center of 5 cm (border of the luminous lightning channel) - 0.93 MPa,
• at a distance of 0.5 m - 0.025 MPa (destruction of fragile building structures and human injuries),
• at a distance of 5 m - 0.002 MPa (breaking glass and temporarily stunning a person).

At greater distances, the shock wave degenerates into a sound wave - thunder.

People and lightning

Lightning is a serious threat to human life. The defeat of a person or animal by lightning often occurs in open spaces, since the electric current travels along the shortest path “thundercloud-ground”. Often lightning strikes trees and transformer installations on the railway, causing them to catch fire. It is impossible to be struck by ordinary linear lightning inside a building, but there is an opinion that so-called ball lightning can penetrate through cracks and open windows. Normal lightning is dangerous for television and radio antennas located on the roofs of high-rise buildings, as well as for network equipment.

The same pathological changes are observed in the body of victims as in case of electric shock. The victim loses consciousness, falls, convulsions may occur, and breathing and heartbeat often stop. It is common to find “current marks” on the body, where electricity enters and exits. In case of death, the cause of cessation of basic vital functions is a sudden stop of breathing and heartbeat, from the direct effect of lightning on the respiratory and vasomotor centers of the medulla oblongata. So-called lightning marks, tree-like light pink or red stripes often remain on the skin, disappearing when pressed with fingers (they persist for 1 - 2 days after death). They are the result of the expansion of capillaries in the area of ​​lightning contact with the body.

Lightning travels in a tree trunk along the path of least electrical resistance, releasing a large amount of heat, turning water into steam, which splits the tree trunk or, more often, tears off sections of bark from it, showing the lightning path. In subsequent seasons, the trees usually repair the damaged tissue and may close the entire wound, leaving only a vertical scar. If the damage is too severe, wind and pests will eventually kill the tree. Trees are natural lightning conductors, and are known to provide protection from lightning strikes to nearby buildings. When planted near a building, tall trees catch lightning, and the high biomass of the root system helps ground the lightning strike.

For this reason, you should not hide from the rain under trees during a thunderstorm, especially under tall or solitary trees in open areas.

Musical instruments are made from trees struck by lightning, attributing unique properties to them.

Lightning and electrical installations

Lightning strikes pose a major hazard to electrical and electronic equipment. When lightning directly hits the wires in the line, an overvoltage occurs, causing destruction of the insulation of electrical equipment, and high currents cause thermal damage to the conductors. To protect against lightning overvoltages, electrical substations and distribution networks are equipped with various types of protective equipment such as arresters, nonlinear surge arresters, and long-spark arresters. To protect against direct lightning strikes, lightning rods and lightning protection cables are used. Electromagnetic pulses created by lightning are also dangerous for electronic devices.

Lightning and aviation

Atmospheric electricity in general and lightning in particular pose a significant threat to aviation. A lightning strike on an aircraft causes a large current to spread through its structural elements, which can cause their destruction, fire in fuel tanks, equipment failures, and loss of life. To reduce risk, the metal elements of the outer skin of aircraft are carefully electrically connected to each other, and non-metallic elements are metallized. This ensures low electrical resistance of the housing. To drain lightning current and other atmospheric electricity from the body, aircraft are equipped with arresters.

Due to the fact that the electrical capacity of an aircraft in the air is small, the “cloud-to-aircraft” discharge has significantly less energy compared to the “cloud-to-ground” discharge. Lightning is most dangerous for a low-flying airplane or helicopter, since in this case the aircraft can play the role of a conductor of lightning current from the cloud to the ground. It is known that aircraft at high altitudes are relatively often struck by lightning, and yet, cases of accidents for this reason are rare. At the same time, there are many known cases of aircraft being struck by lightning during takeoff and landing, as well as while parked, which resulted in disasters or destruction of the aircraft.

Lightning and surface ships

Lightning also poses a very big threat to surface ships due to the fact that the latter are elevated above the sea surface and have many sharp elements (masts, antennas) that are concentrators of electric field strength. In the days of wooden sailing ships with a high specific resistance of the hull, a lightning strike almost always ended tragically for the ship: the ship burned down or was destroyed, and people died from electric shock. Riveted steel ships were also vulnerable to lightning. The high resistivity of the rivet seams caused significant local heat generation, which led to the occurrence of an electric arc, fires, destruction of the rivets and the appearance of water leaks in the body.

The welded hull of modern ships has low resistivity and ensures safe spreading of lightning current. The protruding elements of the superstructure of modern ships are reliably electrically connected to the hull and also ensure the safe spread of lightning current.

Human activities that cause lightning

During a ground-based nuclear explosion, a fraction of a second before the arrival of the boundary of the fiery hemisphere, several hundred meters (~400-700 m when compared with an explosion of 10.4 Mt) from the center, the gamma radiation that reaches it produces an electromagnetic pulse with a intensity of ~100-1000 kV/ m, causing lightning discharges striking from the ground upward before the arrival of the border of the fiery hemisphere.

see also

	lightning in Wiktionary
	Category:Lightning on Wikimedia Commons

Notes

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2. Cosmic rays blamed for lightning Lenta.Ru, 09.02.2009
3. Red Elves and Blue Jets
4. ELVES, a primer: Ionospheric Heating By the Electromagnetic Pulses from Lightning
5. Fractal Models of Blue Jets, Blue Starters Show Similarity, Differences to Red Sprites
6. V.P. Pasko, M.A. Stanley, J.D. Matthews, U.S. Inan, and T.G. Wood (March 14, 2002) "Electrical discharge from a thundercloud top to the lower ionosphere," Nature, vol. 416, pages 152-154.
7. The appearance of UFOs was explained by sprites. lenta.ru (24.02.2009). Archived from the original on August 23, 2011. Retrieved January 16, 2010.
8. John E. Oliver Encyclopedia of World Climatology. - National Oceanic and Atmospheric Administration, 2005. - ISBN 978-1-4020-3264-6
9. . National Oceanic and Atmospheric Administration. Archived
10. . NASA Science. Science News. (December 5, 2001). Archived from the original on August 23, 2011. Retrieved April 15, 2011.
11. K. BOGDANOV “LIGHTNING: MORE QUESTIONS THAN ANSWERS.” “Science and Life” No. 2, 2007
12. Zhivlyuk Yu.N., Mandelstam S.L. On the temperature of lightning and the force of thunder // JETP. 1961. T. 40, issue. 2. pp. 483-487.
13. N. A. Kun “Legends and Myths of Ancient Greece” LLC “AST Publishing House” 2005-538, p. ISBN 5-17-005305-3 Pages 35-36.
14. Editors: Mariko Namba Walter,Eva Jane Neumann Fridman Shamanism: an encyclopedia of world beliefs, practices, and culture. - ABC-CLIO, 2004. - T. 2. - P. 442. - ISBN 1-57607-645-8
15. // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional ones). - St. Petersburg. , 1890-1907.
16. Rules of behavior during a thunderstorm (Russian). VLBoat.ru. Archived from the original on August 23, 2011. Retrieved March 17, 2010.