Tornado is an atmospheric phenomenon. What is a natural phenomenon of a tornado. What is a cascade and a case

Nature "endows" a person with a variety of destructive elements. One of them is a tornado.

A tornado is a veritable natural disaster, in which hundreds of people have died and are killed every year. Interestingly, even in ancient times, people managed to unravel the cause of the appearance of killer vortices, but even today we find it difficult to cope with this gigantic element. We have not learned how to calm tornadoes. But the total number of these "killers" is increasing every year. What caused this? First of all, the reason for the increase in the number of tornadoes lies in the deterioration of the environment, climate change.

Tornado: causes of occurrence

How does a tornado form? This question worries many.
A tornado is a powerful stream of air that rotates at an incredibly high speed. Other names for tornadoes include "thrombus", "meso-hurricane" and the well-known name "tornado". A funnel that forms during a tornado destroys buildings and kills people. All objects that fall into it turn into real chips. The tornado becomes visible thanks to dust and trapped objects.
A tornado has the following characteristics:

• the base of the tornado column can reach four hundred meters;
• tornado diameter can be from 40 m (on water) to 3000 m (on land);
• tornado speed - 20-60 km / h;
• the air rotation speed in the tornado funnel reaches more than 1200 km / h.

All things, buildings, objects that accidentally fall into a tornado are torn apart due to the difference in pressure between the parts of the funnel (external and internal).
There is no reliable determination of the cause of the tornado. Scientists only assume that the element occurs when warm humid air collides with a cold dry "dome" that forms over cold water, land. When air masses of different temperatures come into contact, heat (energy) is released, a rarefaction region is created, and a tornado funnel appears.

Tornado: varieties

Tornadoes can come in different shapes and sizes.
The most famous tornadoes:

• vague (resemble thick clouds, rarely appear);
• whip-like (they are thin, similar in appearance to a whip, whip);
• composite (they are a combination of several tornado vortices and pose the greatest threat to people);
• fiery (these tornado vortices are formed during a volcanic eruption, they carry fiery masses for several tens of thousands of meters).
• water (when the funnel touches water, water drops rise into the air).
• sandy (these whirlwinds of dust, being analogs of an ordinary tornado, appear in the desert, they are two or three meters in diameter).

The classification of tornadoes is, as a rule, based on the places of formation of the elements.

Why are tornadoes so dangerous for the inhabitants of the planet?

What associations do you have when you hear "tornado"? Of course, first of all, these are colossal destruction of a large scale.
The tornado picks up everything that comes in its way. They can move even large and heavy objects in the air, including houses, cars, trees, for several kilometers. What can we say about people. Only the lucky ones survive in the middle of a tornado. But there are many victims not only among those who were sucked in by the tornado funnel, but also among those who were near the tornado. Most often, people are knocked down, wounded by the debris flying out of the tornado.

It should be noted that nowadays people know in advance about the approaching tornado. Timely alerts from forecasters save lives. Otherwise, the number of victims would have been much higher. Most often, those who hunt for them die in tornado vortices. There are people who are ready to risk their own lives for a beautiful photo, useful video. It is clear that a tornado is an alluring and little studied phenomenon. Therefore, many want to get closer to him. But don't underestimate the element. She does not forgive a frivolous attitude.

For example, at the end of April 1989 in Bangladesh, residents of the city of Shatursh ignored the news that a powerful tornado was approaching. And this was the largest, most tragic tornado in the entire history of the world. Not surprisingly, he made it to the pages of the Guinness Book of Records. The tornado took 1300 lives with it, inflicting colossal destruction. Why did it happen? The key reason lies in the frivolous attitude towards the elements.
The country of the tornado is America. Several hundred different tornadoes happen on its territory every year. Most often they can be seen in Florida. There, tornadoes occur every day from May to September. Of course, not all of them are deadly, many do not touch the surface of the earth at all. But many tornadoes are still dangerous to humans.
An important fact: tornadoes occur not only on Earth, but also on Venus, Mars, Jupiter and Neptune.

The winds of great destructive power include tornado (in the USA - tornado). - This is a strong atmospheric vortex that appears in thunderclouds and descends in the form of a dark sleeve towards land or water with a vertical but partially curved axis.

The appearance of a tornado

A tornado is also possible in clear, cloudless weather. In the upper and lower parts, the tornado has funnel-shaped expansions. The air in a tornado rotates, as a rule, counterclockwise at a speed of up to 300 km / h, while it spirals upward, drawing in dust or water due to the resulting pressure difference. The air pressure in the tornado is lowered. The height of the sleeve can reach 800-1500 m, the diameter above water is tens of meters, and over land - hundreds of meters. The tornado lasts from several minutes to several hours. The length of the path is from hundreds of meters to tens of kilometers.

The highest wind speed in a tornado was recorded on April 2, 1958 in Texas (USA). It was 450 km / h.

A tornado usually occurs in the warm sector of a cyclone, more often in front of a cold front, and moves in the same direction as the cyclone. It is accompanied by thunderstorms, rain, and hail. In those cases when the tornado reaches the surface of the earth, destruction is inevitable. This is due to two factors: the ramming blow of the rapidly rushing air and the large pressure difference between the inner and peripheral parts of the column. Tornadoes are especially dangerous for ships on the high seas.

The atmospheric conditions required for tornadoes to occur include:

High humidity;

Temperature instability and convergence at one point of warm humid air at lower altitudes;

Cool dry on large.

At first, you can see a dark rotating funnel, then there is silence for a while, and then a tornado suddenly appears. The air in a tornado rotates counterclockwise and at the same time rises in a spiral, in contact with the surface of the Earth, pulls in dust, water and various objects. These destruction are associated with the action of rapidly rotating air and a sharp rise of air masses upward. As a result of these phenomena, some objects (cars, light houses, roofs of buildings, people and animals) can be lifted off the ground and transported hundreds of meters. Such an action of a tornado often causes the destruction of raised objects, and people are injured and contused, which can lead to death. Also tornadoes lead to plane crashes. Tornadoes do not exist for a long time, from several minutes to several hours, during this time they travel from hundreds of meters to tens of kilometers.

Tornado

Tornado - a tornado of gigantic destructive power. The term commonly used in the United States comes from the distorted Spanish word for "throne", meaning thunderstorm.

Tornadoes usually occur

they occur in the warm sector of the cyclone, when the collision of warm and cold air currents occurs due to the effect of a strong side wind. A tornado begins, like an ordinary thunderstorm, often accompanied by rain and hail.

The wind speed in a tornado is so high that it is impossible to measure it with any anemometers. In the USA, it is determined using Doppler radar. According to the speed of rotation of the air in the funnel, tornadoes are classified into six categories. A scale with six categories F0-F5 for the classification of American tornadoes, introduced by Professor Theodore Fujita of the University of Chicago in 1971. The F1 category on the Fujita scale corresponds to 12 points on the Beaufort scale (32 m / s, hurricane). Fujita also introduced the F6-F12 categories (from 142 m / s to the speed of sound), apparently just in case. But the recorded wind speed in a tornado never exceeded category F5, it is assumed that such tornadoes will not be observed.

Fujita scale

The homeland of the tornado is the United States. It is there that this natural disaster is most often observed.

The reason for the formation of such powerful and frequent tornadoes in the United States is the warm, humid air from the Gulf of Mexico.

Air collides in the United States with cold air from Canada and dry air from the Rocky Mountains. Under such conditions, a large number of thunderstorms occur, which carry the threat of a tornado. The most destructive and deadly tornadoes form under the huge cumulonimbus clouds, called supersells in the United States, these clouds rotate to form mesocyclones. These clouds often bring heavy hail, squally winds, heavy thunderstorms and showers, and tornadoes.

About 1,000 tornadoes occur in the US every year... It is difficult to say for sure, since some tornadoes occur in sparsely populated areas and therefore are not recorded.

Basically, the tornado season lasts from early spring to mid-summer. In some states, the peak of the tornado occurs in May, in others - in June or even July. But in general, tornadoes can occur at any time of the year.

There is even a Tornado Alley in the USA. This is the historical name for the central American states that have seen the most tornadoes. However, tornadoes can occur anywhere: on the west and east coast of the United States, as well as in Canada and other countries.

Most tornadoes (but not all!) Have cyclonic rotation, i.e. counterclockwise in the northern hemisphere and clockwise in the southern. Anticyclonic tornadoes rotate clockwise in the northern hemisphere. They most often appear in the form of water tornadoes, and there are also many cases of simultaneous observation of cyclonic and anticyclonic tornadoes under the same thunderstorm.

In the United States, tornadoes are predicted by the National Weather Service.Tornado warnings are sent by regional offices of the National Weather Service. The Storm Prediction Center deals with adverse weather events. Tornadoes in Canada are predicted by the Canada Meteorological Service.

Usually tornadoes bypass large cities. It's just that the city center is located on a very small area in comparison with the area of \u200b\u200bthe whole country. Therefore, the likelihood of a tornado hitting the city center is very low. For example, the area of \u200b\u200bcentral Dallas is only three square miles. However, city centers can also suffer from tornadoes. So in St. Louis, tornadoes in the city center were observed at least four times. But there have been numerous cases of tornadoes in large cities. For example, the tornado in Oklahoma City on May 3, 1999. Thanks to the well-functioning system of warning the population through the media, only 36 people died that day. But the damage caused exceeded $ 1 billion. It was the most expensive tornado in American history. Moreover, this tornado did not affect the city center.

According to statistics, the city that suffers the most from tornadoes is Oklahoma City. The total number of tornadoes that have been registered in this city is over 100.

The strongest tornado occurred in Texas on June 9, 1971. From time to time the diameter of the tornado reached three kilometers !!! There may have been other, even larger tornadoes, but they were not recorded.

The emergence of a tornado

The emergence of a tornado - an amazing mystery, for some reason there is surprisingly little information about the origin of these phenomena, but this phenomenon cannot be called small or insignificant. And predicting their appearance could be a significant achievement in general. In nature, the formation of vortices occurs all the time. Everyone has seen the formation of a funnel in the flowing water from the bath, marveling at the energy of the water as it formed.

But a huge tornado and a small funnel in the bathroom - these are phenomena of the same order, occurring according to the same laws. True, in these two cases there is a significant difference: in the tornado funnel, the swirling mass rises up, and in the bath funnel it goes down. From this we can conclude: a liquid or gas can easily be brought into rotation, and the formation of a vortex, this beautiful cone, occurs when the swirling mass moves up or down along the axis of rotation.

Vortex - a fairly stable process and the source of energy for its existence cannot be anything other than the thermal energy of the environment. How do streams move inside a vortex? It would be appropriate here to recall one small experience of the great Einstein.

He was somehow very interested in the process that occurs when stirring with a spoon of tea in an ordinary cup. It turns out that floating tea leaves in some incomprehensible way always find themselves in the center of rotation during intensive rotation of water. Einstein explained this as follows: naturally, the entire cylinder of water rotates, centrifugal force acts on the water. But the water layers above and below are in unequal conditions. The lower layers experience friction on contact with the bottom of the glass and rotate more slowly. The upper layers rotate freely without experiencing any particular problems in contact with air. Therefore, the top layer rotates faster, experiencing a greater centrifugal force. Therefore, a circular current appears in the water column, shown by blue curved arrows. And all the tea leaves gather towards the center and even tend to rise a little upward.

Chronicle of events

Tornadoes are observed in all regions of the world. They occur most frequently in the United States. Australia, North East Africa. In North America, tornadoes are known as tornadoes. Also known as blood clots.

In 1925, a tornado claimed the lives of 350 people in the United States, and 2,000 were injured. The total loss was $ 40 million. In total, 689 people died from tornadoes in the United States this year.

In 1982, more than 40 tornadoes emerged in the Black Sea and transported huge amounts of water to land. The settlement of Dzhubga and nearby settlements of the Krasnodar Territory became a victim of tornadoes. Houses, cars, trees were washed into the sea.

Two years later. but already on the vast territory of the Volgo-Vyatka region, a large number of destructive tornadoes formed. The speed of rotation of vortex air currents reached 200 km / h, the width of the traffic lane - up to 500 m, the distance traveled - up to several tens of kilometers. Thousands of buildings were destroyed, trees, water and silo towers were felled, water and electricity supplies were interrupted, and transport was stopped. In 1988, a tornado up to 1 km wide hit Pavlovskaya station of the Krasnodar Territory. As a result, about 500 houses were destroyed. During the last rain, hail fell the size of a hen's egg, which pierced the roofs of houses, destroyed crops.

Description

Inside the funnel, the air descends, and outside it rises, rotating rapidly, creating an area of \u200b\u200bhighly rarefied air. The vacuum is so significant that closed objects filled with gas, including buildings, can explode from the inside due to pressure differences. This phenomenon enhances the damage caused by the tornado and makes it difficult to determine the parameters in it. Determining the speed of air movement in a funnel is still a serious problem. Basically, estimates of this value are known from indirect observations. Depending on the intensity of the vortex, the speed of the flow in it can vary. It is believed that it exceeds 18 m / s and can, according to some indirect estimates, reach 1300 km / h. The tornado itself moves along with the cloud that generates it. This movement can give speeds of tens of km / h, usually 20-60 km / h. According to indirect estimates, the energy of a conventional tornado with a radius of 1 km and an average speed of 70 m / s is comparable to the energy of a reference atomic bomb, similar to the one detonated in the United States during the Trinity tests in New Mexico on July 16, 1945. (unavailable link) The record for the lifetime of a tornado can be considered the Mattun tornado, which on May 26, 1917, in 7 hours 20 minutes, passed 500 km across the United States, killing 110 people. The width of the vague funnel of this tornado was 0.4-1 km; a whip-like funnel was visible inside it. Another famous case of tornado is the tornado of the Three States (Tristate tornado), which passed through the states of Missouri, Illinois and Indiana on March 18, 1925, making a journey of 350 km in 3.5 hours. The diameter of its vague funnel ranged from 800 m to 1.6 km.

In the Northern Hemisphere, air rotation in tornadoes usually occurs counterclockwise. This may be due to the directions of mutual displacements of air masses on the sides of the atmospheric front, on which the tornado is formed. Cases of reverse rotation are also known. In areas adjacent to the tornado, air is lowered, as a result of which the vortex is closed.

At the point of contact of the base of the tornado funnel with the surface of the earth or water, cascade - a cloud or column of dust, debris and objects raised from the ground or water spray. When a tornado forms, the observer sees how a cascade rises from the ground towards the funnel descending from the sky, which then covers the lower part of the funnel. The term comes from the fact that the debris, having risen to a certain insignificant height, can no longer be held by the flow of air and fall to the ground. The funnel, without touching the ground, can envelop case... Merging, the cascade, the case and the mother cloud create the illusion of a tornado funnel wider than it really is.

Sometimes a vortex formed on the sea is called a tornado, and on land - a tornado. Atmospheric vortices, similar to tornadoes, but formed in Europe, are called thrombi. But more often than not, all of these three concepts are considered synonymous.

Reasons for education

The reasons for the formation of tornadoes have not yet been fully studied. It is possible to indicate only some general information that is most characteristic of typical tornadoes.

Tornadoes go through three main stages in their development. At the initial stage, an initial funnel appears from the thundercloud, hanging above the ground. Cold air layers located directly under the cloud rush down to replace the warm ones, which, in turn, rise up (such an unstable system is usually formed when two atmospheric fronts - warm and cold) join. The potential energy of this system is converted into kinetic energy of the rotational motion of the air. The speed of this movement increases and it takes on its classic look.

The rotational speed increases over time, while in the center of the tornado, the air begins to rapidly rise upward. This is how the second stage of the tornado's existence proceeds - the stage of the formed vortex of maximum power. The tornado is fully formed and moves in different directions.

The final stage is the destruction of the vortex. The power of the tornado weakens, the funnel narrows and breaks off the surface of the earth, gradually rising back into the parent cloud.

The lifetime of each stage is different and ranges from several minutes to several hours (in exceptional cases). The speed of tornadoes is also different, on average - 40 - 60 km / h (in very rare cases it can reach 210 km / h).

Places of tornado formation

Places where tornadoes can form are orange on the map

The second region of the world where conditions for the formation of tornadoes arise is Europe (except for the Iberian Peninsula), and the entire European territory of Russia, with the exception of the south of Russia, Karelia and the Murmansk region, as well as other northern regions.

Thus, tornadoes are mainly observed in the temperate zone of both hemispheres, from approximately 60th parallel to 45th parallel in Europe and 30th parallel in the United States.

Also, tornadoes are recorded in the east of Argentina, South Africa, west and east of Australia and a number of other regions, where conditions of collision of atmospheric fronts can also occur.

Classification of tornadoes

Scourge-like

This is the most common type of tornado. The funnel looks smooth, thin, and can be quite sinuous. The funnel is much longer than its radius. Weak tornadoes and tornado funnels sinking into the water, as a rule, are whip-like tornadoes.

Vague

They look like shaggy, rotating clouds reaching the ground. Sometimes the diameter of such a tornado even exceeds its height. All funnels of large diameter (over 0.5 km) are vague. These are usually very powerful vortices, often composite. They cause huge damage due to their large size and very high wind speed.

Composite

They may consist of two or more separate blood clots around the main central tornado. Such tornadoes can be of almost any power, however, most often they are very powerful tornadoes. They cause significant damage over large areas. ...

Fiery

These are common tornadoes generated by a cloud formed as a result of a violent fire or volcanic eruption. It was these tornadoes that were first artificially created by man (the experiments of J. Dessens in the Sahara, which continued in 1960-1962). The tongues of flame are "absorbed" and are drawn to the mother cloud, forming a fiery tornado. It can spread a fire for tens of kilometers. They are scourge-like. They cannot be vague (fire is not under pressure, like whip-like tornadoes.

Aquatic

These are tornadoes that formed over the surface of the oceans, seas, and in the rare case of lakes. They "absorb" water (why? See above) and form water tornadoes. They "absorb" waves and water, forming, in some cases, whirlpools, which are drawn to the mother cloud, forming a water tornado. They are scourge-like. They cannot be vague (like fiery ones: water is not under pressure, like whip-like tornadoes).

Earthen

These tornadoes are very rare, they form during destructive cataclysms or landslides, sometimes earthquakes above 7 on the Richter scale, very high pressure drops, the air is highly discharged. A whip-like tornado, a "carrot" thick part to the ground, inside a dense funnel, a thin trickle of earth inside, a "second shell" of earthen slurry (if a landslide). In the case of earthquakes, it raises stones, which is very dangerous.

Ball

It is not yet known how it "works". It has not yet been proven that it exists. It can be fire, water, earth, air, and, what is most dangerous, gas, which causes explosions like ball lightning. In general, this is a voluminous oval or ball that spins at a frantic speed, then flattens out, flattening all its contents (if a person gets there, it will look like a thick pancake, or torn to pieces). Was in Brazil, during the fire tornado, but due to its small size (they are about 10 - 50 meters in diameter) did not notice it.

Snowy

These are snow tornadoes during a severe blizzard.

Sand vortices

Sand vortices

It is necessary to distinguish from the considered tornadoes sandy "whirlwinds" ("dusty devils") observed in deserts (Egypt, Sahara); unlike the previous ones, the latter are sometimes called thermal vortices. Similar in appearance to real tornadoes, the sandy whirlwinds of deserts have nothing in common with the former either in size, origin, or in structure and actions. Arising under the influence of the local incandescence of the sandy surface with the sun's rays, the sand vortices are a real cyclone (barometric minimum) in miniature. A decrease in air pressure under the influence of heating, causing an influx of air from the sides to a heated place, under the influence of the rotation of the Earth, and even more - the incomplete symmetry of such an upward flow, forms a rotation that gradually grows into a funnel and sometimes, under favorable conditions, takes on rather impressive dimensions. Carried away by the vortex motion, the masses of sand are lifted upward in the center of the vortex into the air, and thus a sand column is created, representing a kind of tornado. In Egypt, such eddies of sand were observed up to 500 and even up to 1000 meters in height with a diameter of up to 2-3 meters. With the wind, these vortices can move, carried away by the general movement of the air. After holding out for some time (sometimes up to 2 hours), such a vortex gradually weakens and crumbles.

Striking factors

Tornado precautions

It is necessary to take refuge in the most durable reinforced concrete structure with a steel frame, keeping close to the strongest wall, and the best option for shelter is an underground shelter or a cave. Staying in a car or in a trailer, given the large lifting force of a tornado, is deadly, it is also life-threatening to meet the elements outdoors.

If a tornado finds a person in an open space, then you need to move at maximum speed perpendicular to the visible movement of the funnel. Or, if it is impossible to retreat, take refuge in depressions on the surface (ravines, pits, trenches, road ditches, ditches, ditches) and snuggle tightly to the ground face down, covering your head with your hands. This will help to significantly reduce the likelihood and severity of injuries from objects and debris carried by the tornado.

In a small one-two-storey private house, you can use the basement (here, for such an emergency, it is wise to place a supply of water and canned food, also candles or LED lamps), if there is no basement, then you should stay in the bathroom or in the center of a small room on the lower floor, it is possible under solid furniture, but away from windows. It will be prudent to dress in tight clothes, taking money and documents with you. To prevent the house from exploding from the pressure drop caused by the blowing of air by a vortex, it is recommended to close all windows and doors tightly from the side of the approaching tornado, and open wide open on the opposite side and fix it. According to safety precautions, it is advisable to turn off the gas and turn off the electricity.

Interesting facts from the chronicle of tornadoes

Current research

Literature

• Varaksin A. Yu., Romash M. E., Kopeytsev V. N. Tornado. - Moscow: Fizmatlit, 2011 .-- 344 p. - 300 copies. - ISBN 978-5-9221-1249-9

Notes

1. Soviet encyclopedic dictionary. - M .: "Soviet Encyclopedia", 1981. - 1600 p.
2. D. V. Nalivkin Tornadoes. - M .: Nauka, 1984 .-- 111 p.
3. "Tornado" // Etymological Dictionary of the Russian Language. / comp. M.R.Fasmer, - M .: Progress 1964-1973
4. S.P. Khromov, M.A. Petrosyants. Small-scale eddies. Meteorology and climatology... Archived from the original on August 23, 2011. Retrieved June 8, 2009.
5. (unavailable link)
6. Mezentsev V.A., "Unsolved Earth: stories about how they discovered and continue to discover our planet" / reviewer - Dr. Geogr. Sciences E. M. Murzaev, - M .: Mysl, 1983, S. 136-142
7. G. Lyuboslavsky: // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.
8. I. V. Chernysh, "Traveling encyclopedia of the traveler", - M .: FAIR-PRESS, 2006, S. 289, ISBN 5-8183-0982-7
9. John Wiseman "A complete guide to survival", - M .: AST, 2011, S. 549, ISBN 978-5-17-045760-1
10. Konstantin Ranks "Desert Russia", - M .: Eksmo, 2011, S. 185-187, ISBN 978-5-699-46249-0
11. Kravchuk P.A. Records of nature. - L.: Erudit, 1993 .-- 216 p. - 60,000 copies - ISBN 5-7707-2044-1
12. (eng.) National Severe Storms Laboratory VORTEX: Unraveling the Secrets. National Oceanic and Atmospheric Administration (October 30, 2006). Archived from the original on November 4, 2012.
13. (eng.) Micheal H Mogil Extreme Weather. - New York: Black Dog & Leventhal Publisher, 2007. - P. 210-211. - ISBN 978-1-57912-743-5
14. (eng.) Kevin McGrath Mesocyclone Climatology Project. University of Oklahoma (November 5, 1998). Archived from the original on November 4, 2012. Retrieved November 19, 2009.
15. (English) Seymour, Simon (2001). Tornadoes. New York City, New York: HarperCollins. p. 32. ISBN 978-0-06-443791-2.

see also

Links

• Tornado in Krasnogorsk on August 3, 2007 - meteorological data and video on the website Meteoweb.ru, 07/19/2008.

DEATH AND TORNADO.Tornado (synonyms - tornado, thrombus, meso-hurricane) is a very strong rotating vortex with dimensions less than 50 km horizontally and less than 10 km vertically, with hurricane wind speeds of more than 33 m / s. The energy of a typical tornado with a radius of 1 km and an average speed of 70 m / s, according to estimates by S.A. Arsenyev, A.Yu. Gubar and V.N. Nikolaevsky, is equal to the energy of a reference atomic bomb of 20 kilotons of TNT, similar to the first atomic bomb detonated USA during the Trinity trials in New Mexico on July 16, 1945. The shape of tornadoes can be varied - a column, a cone, a glass, a barrel, a whip-like rope, an hourglass, the horns of the "devil", etc., but most often tornadoes have the shape of a rotating trunk, pipe or funnel hanging from the mother cloud (hence their names: tromb - pipe in French and tornado - rotating in Spanish). The photographs below show three tornadoes in the United States: in the form of a trunk, a column and a pillar at the moment they touch the surface of the earth covered with grass (a secondary cloud in the form of a cascade of dust does not form near the earth's surface). Rotation in tornadoes occurs counterclockwise, as in cyclones in the northern hemisphere of the Earth.

In atmospheric physics, tornadoes are referred to as meso-scale cyclones and must be distinguished from synoptic cyclones of middle latitudes (with dimensions of 1500–2000 km) and tropical cyclones (with dimensions of 300–700 km). Meso-scale cyclones (from the Greek meso - intermediate) refer to the middle of the range between turbulent eddies with sizes of the order of 1000 m and less and tropical cyclones formed in the convergence (convergence) zone of trade winds at 5th degree north latitude and above, up to 30 th degree of latitude. In some tropical cyclones, the wind reaches hurricane speeds of 33 m / s or more (up to 100 m / s), and then they turn into typhoons of the Pacific Ocean, Atlantic hurricanes or willy-villas in Australia.

Typhoon is a Chinese word that translates as "the wind that beats." Hurricane is the English word hurricane translated into Russian. In large synoptic cyclones of middle latitudes, the wind reaches a storm speed (from 15 to 33 m / s), but sometimes even here it can become a hurricane, i.e. exceed the limit of 33 m / s. Synoptic cyclones are formed on the zonal atmospheric current directed in the troposphere of the middle latitudes of the northern hemisphere from west to east, like very large planetary waves with a size comparable to the radius of the Earth (6378 km - the equatorial radius). Planetary waves arise on a rotating, spherical Earth and on other planets (for example, Jupiter) under the influence of changes in the Coriolis force with latitude and (or) an inhomogeneous relief (orography) of the underlying surface. The first to realize the importance of planetary waves for weather forecasting in the 1930s were Soviet scientists E.N. Blinova and I.A.Kibel, as well as the American scientist K. Rossby, therefore planetary waves are sometimes called Blinova-Rossby waves.

Tornadoes often form on tropospheric fronts - interfaces in the lower 10-kilometer layer of the atmosphere, which separate air masses with different wind speeds, temperatures and air humidity. In the region of a cold front (cold air flows into warm), the atmosphere is especially unstable and forms a multitude of rapidly rotating turbulent vortices in the tornado's mother cloud and below it. Strong cold fronts are formed during the spring-summer and autumn periods. They separate, for example, cold and dry air from Canada from warm and humid air from the Gulf of Mexico or from the Atlantic (Pacific) Ocean over the United States. There are known cases of small tornadoes in clear weather in the absence of clouds over the overheated surface of the desert or ocean. They can be completely transparent and only the lower part, dusty with sand or water, makes them visible.

Tornadoes are also observed on other planets of the solar system, for example, on Neptune and Jupiter. MF Ivanov, FF Kamenets, AM Pukhov and VE Fortov studied the formation of tornado-like vortex structures in the atmosphere of Jupiter when the fragments of comet Shoemaker - Levy fell on it. On Mars, strong tornadoes cannot arise due to the rarefaction of the atmosphere and very low pressure. On the contrary, the likelihood of powerful tornadoes on Venus is high, since it has a dense atmosphere, discovered in 1761 by MV Lomonosov. Unfortunately, on Venus, a continuous cloud layer about 20 km thick hides its lower layers for observers on Earth. Soviet automatic stations (AMS) of the Venus type and the American AMS of the Pioneer and Mariner types found winds up to 100 m / s in the clouds on this planet at an air density 50 times higher than the air density on Earth at sea level, but they did not observe tornadoes. However, the time spent by the AMS on Venus was short and one can expect reports of tornadoes on Venus in the future. Probably, tornadoes on Venus arise in the border zone separating the dark cold side of a very slowly rotating planet from the side illuminated and heated by the Sun. This assumption is supported by the discovery of thunderstorms on Venus and Jupiter, the usual satellites of tornadoes and tornadoes on Earth.

Tornadoes and tornadoes should be distinguished from squall storms formed on atmospheric fronts, characterized by a rapid (within 15 minutes) increase in wind speed to 33 m / s and then its decrease to 1–2 m / s (also within 15 minutes). Heavy storms break trees in the forest, can destroy a light structure, and at sea they can even sink a ship. On September 19, 1893, the battleship "Rusalka" on the Baltic Sea was overturned by a squall and immediately sank. 178 crew members were killed. Some cold-front blast storms reach the tornado stage, but they are usually weaker and do not form air vortexes.

The air pressure in cyclones is reduced, but in tornadoes, the pressure drop can be very strong, up to 666 mbar at a normal atmospheric pressure of 1013.25 mbar. The mass of air in a tornado revolves around a common center ("eye of the storm", where there is a calm) and the average wind speed can reach 200 m / s, causing catastrophic destruction, often with human casualties. Inside the tornado, there are smaller turbulent vortices that rotate at speeds exceeding the speed of sound (320 m / s). The most evil and cruel tricks of tornadoes and tornadoes are associated with hypersonic turbulent vortices, which tear people and animals apart or rip off their skin and skin. The reduced pressure inside tornadoes and tornadoes creates a "pump effect", i.e. drawing in ambient air, water, dust and objects, people and animals inside the blood clot. The same effect leads to the rise and explosion of houses falling into the depression funnel.

The classic tornado country is the United States. For example, in 1990, 1100 destructive tornadoes were recorded in the United States. A tornado on September 24, 2001 over a football stadium in College Park in Washington DC caused 3 deaths, injured several people and caused extensive destruction along the way. Over 22,000 people were left without electricity.

In Russia, the Moscow tornadoes of 1904, described in the capital's magazine and newspaper publications as testimonies of numerous eyewitnesses, received the greatest fame. They contain all the main features of typical tornadoes of the Russian plain, observed in other parts of it (Tver, Kursk, Yaroslavl, Kostroma, Tambov, Rostov and other regions).

On June 29, 1904, an ordinary synoptic cyclone passed over the central European part of Russia. In the right segment of the cyclone, a very large cumulonimbus cloud with a height of 11 km appeared. It left the Tula province, passed the Moscow one and went to Yaroslavl. The width of the cloud was 15–20 km, judging by the width of the strip of rain and hail. When the cloud passed over the outskirts of Moscow, the appearance and disappearance of tornado funnels was observed on its lower surface. The direction of the cloud movement coincided with the movement of air in synoptic cyclones (counterclockwise, that is, in this case, from the south-east to the north-west). On the lower surface of the thundercloud, small, light clouds moved quickly and chaotically in different directions. Gradually, an ordered average movement in the form of rotation around a common center was superimposed on the disordered, turbulent air movements, and suddenly a gray pointed funnel hung from the cloud. which did not reach the surface of the Earth and was pulled back into the cloud. A few minutes after that, another crater appeared nearby, which rapidly increased in size and hung down to the Earth. A column of dust rose up towards her, getting higher and higher. A little more and the ends of both funnels joined, the column of the tornado in the direction of the cloud's movement, it expanded upward and became wider and wider. Huts flew into the air, the space around the crater was filled with debris and broken trees. To the west, a few kilometers away, there was another crater, also accompanied by destruction.

Meteorologists of the early 20th century the wind speed in Moscow tornadoes was estimated at 25 m / s, but there were no direct measurements of the wind speed, therefore this figure is unreliable and should be increased two to three times, this is evidenced by the nature of the damage, for example, a curved iron staircase worn through the air, torn off roofs of houses, people and animals raised in the air. Moscow tornadoes of 1904 were accompanied by darkness, terrible noise, roar, whistle and lightning. Rain and heavy hail (400–600 g). According to scientists of the Physics and Astronomy Institute, 162 mm of precipitation fell from a tornado cloud in Moscow

Of particular interest are turbulent eddies inside the tornado, rotating at high speed, so that the surface of the water, for example, in the Yauza or in the Lublin ponds, when the tornado passed, first boiled and seethed like in a cauldron. Then the tornado sucked the water inside itself and the bottom of the reservoir or river was exposed.

Although the destructive power of Moscow tornadoes was significant and newspapers were full of the strongest adjectives, it should be noted that, according to the five-point classification of the Japanese scientist T. Fujita, these tornadoes belong to the category of average (F-2 and F-3). The strongest F-5 class tornadoes are found in the United States. For example, during the tornado on September 2, 1935 in Florida, the wind speed reached 500 km / h, and the air pressure dropped to 569 mm Hg. This tornado killed 400 people and caused the total destruction of buildings in a strip 15–20 km wide. Florida is not called the land of tornadoes for nothing. Here, from May to mid-October, tornadoes appear daily. For example, in 1964 395 tornadoes were registered. Not all of them reach the Earth's surface and cause destruction.

But some, like the 1935 tornado, are striking in their power.

Such tornadoes get their names, for example, the tornado of the Three States on March 18, 1925. It began in Missouri, followed an almost straight path through the entire state of Illinois and ended in Indiana. The duration of the tornado is 3.5 hours, the speed is 100 km / h, the tornado traveled about 350 km. Except for the initial stage, the tornado everywhere did not lift off the surface of the Earth and rolled along it with the speed of a courier train in the form of a black, terrible, madly rotating cloud. In an area of \u200b\u200b164 square miles, everything was turned into chaos. The total number of deaths - 695 people, seriously injured - 2027 people, losses amounting to about $ 40 million, these are the results of the tornado of the Three States.

Tornadoes often occur in groups of two, three, and sometimes more meso-cyclones. For example, on April 3, 1974, more than a hundred tornadoes arose that raged in 11 states of the United States. 24 thousand families were affected, and the damage caused was estimated at $ 70 million. In Kentucky, one of the tornadoes destroyed half of the city of Brandenburg, and other cases of destruction of small American cities by tornadoes are known. For example, on May 30, 1879, two tornadoes, following one after another at intervals of 20 minutes, destroyed the provincial town of Irving with 300 inhabitants in the north of Kansas. One of the convincing testimonies of the enormous power of the tornado is connected with the Irving tornado: a 75 m long steel bridge across the Big Blue River was lifted into the air and twisted like a rope. The remains of the bridge were transformed into a dense compact bundle of steel partitions, trusses and ropes, ripped and bent in the most fantastic ways. This fact confirms the presence of hypersonic vortices inside the tornado. There is no doubt that the wind speed increased when descending from the high and steep bank of the river. Meteorologists know the effect of intensification of synoptic cyclones after passing through mountain ranges, for example, the Ural or Scandinavian mountains. Along with the Irving tornadoes, on May 29 and 30, 1879, two Delphos tornadoes arose west of Irving and Lee's tornado to the southeast. In total, during these two days, which were preceded by very dry and hot weather in Kansas, 9 tornadoes arose.

In the past, tornadoes in the United States caused numerous victims, which was due to poor knowledge of this phenomenon, now the number of victims from tornadoes in the United States is much less - this is the result of the activities of scientists, the US Meteorological Service and a special center for storm prevention, which is located in Oklahoma. After receiving a message about the approaching tornado, prudent US citizens descend into underground shelters and this saves their lives. However, there are also crazy people or even "tornado hunters" for whom this "hobby" sometimes ends in death. The tornado in the city of Shatursh in Bangladesh on April 26, 1989 hit the Guinness Book of Records as the most tragic in the history of mankind. The inhabitants of this city, having received a warning about an impending tornado, ignored it. As a result, 1,300 people died.

Although many of the qualitative properties of tornadoes have been understood by now, an exact scientific theory that makes it possible to predict their characteristics by mathematical calculations has not yet been fully developed. Difficulties are primarily due to the lack of measurement data for physical quantities inside a tornado (average wind speed and direction, air pressure and density, humidity, speed and size of ascending and descending flows, temperature, size and speed of rotation of turbulent vortices, their orientation in space, moments of inertia, moments of impulse and other characteristics of movement depending on spatial coordinates and time). Scientists have at their disposal the results of photographs and filming, verbal descriptions of eyewitnesses and traces of tornado activity, as well as the results of radar observations, but this is not enough. The tornado either bypasses the sites with the measuring devices, or breaks and takes the equipment with it. Another difficulty is that the air movement inside the tornado is essentially turbulent. The mathematical description and calculation of turbulent chaos is the most difficult and still not fully solved problem in physics. Differential equations describing meso-meteorological processes are nonlinear and, unlike linear equations, have not one, but many solutions, from which it is necessary to choose a physically significant one. Only by the end of the 20th century. Scientists have received computers that can solve the problems of meso-meteorology, but their memory and speed are often not enough.

The theory of tornadoes and hurricanes was proposed by Arseniev, A.Yu. Gubar, and V.N. Nikolaevsky. According to this theory, tornadoes and tornadoes arise from a quiet (wind speed of the order of 1 m / s) meso-anticyclone (existing, for example, in the lower or lateral part of a thundercloud) with a size of about 1 km, which is filled (except for the central region, where air rests) by rapidly rotating turbulent vortices formed as a result of convection or instability of atmospheric currents in the frontal regions. At certain values \u200b\u200bof the initial energy and angular momentum of turbulent vortices at the periphery of the mother anticyclone, the average wind speed begins to increase and changes the direction of rotation, forming a cyclone. Over time, the size of the forming tornado increases, the central region ("eye of the storm") is filled with turbulent eddies, and the radius of the maximum winds shifts from the periphery to the center of the tornado. The air pressure in the center of the tornado begins to drop, forming a typical depression vortex. The maximum wind speed and minimum pressure in the eye of the storm are reached 40 minutes 1.1 seconds after the beginning of the tornado formation process. For the calculated example, the radius of maximum winds is 3 km with a total tornado size of 6 km, the maximum wind speed is 137 m / s, and the largest pressure anomaly (the difference between the current pressure and normal atmospheric pressure) is 250 mbar. In the eye of a tornado, where the average wind speed is always zero, turbulent eddies reach their maximum size and rotation speed. After reaching the maximum wind speed, the tornado begins to fade, increasing its size. The pressure increases, the average wind speed decreases, and the turbulent vortices degenerate, so that their size and rotation speed decrease. The total lifetime of a tornado for the example calculated by S.A. Arsen'ev, A.Yu. Gubar, and V.N. Nikolaevsky is about two hours.

The energy source that powers the tornado is the highly rotating turbulent eddies present in the original turbulent flow.

In fact, in the proposed theory there are two thermodynamic subsystems - subsystem A corresponds to the mean motion, and subsystem B contains turbulent vortices. The calculations did not take into account the arrival of new turbulent vortices into the tornado from the environment (for example, thermals - floating upward, rotating convective bubbles formed on the overheated surface of the Earth), therefore the complete A + B system is closed and the total kinetic energy of the entire system decreases with time from - for the processes of molecular and turbulent friction. However, each of the subsystems is open in relation to the other and energy exchange can take place between them. Analysis shows that if the values \u200b\u200bof the order parameters (or, as they are called, the critical similarity numbers, of which there are five in the theory) are small, then the average perturbation in the form of an initial anticyclone does not receive energy from turbulent vortices and decays under the action of dissipation (energy dissipation) processes. This solution corresponds to the thermodynamic branch - dissipation tends to eliminate any deviation from the equilibrium state and forces the thermodynamic system to return to the state with maximum entropy, i.e. to rest (a state of thermodynamic death sets in). However, since the theory is nonlinear, this solution is not unique, and for sufficiently large values \u200b\u200bof the control order parameters, another solution takes place - the motions in subsystem A are intensified and amplified by the energy of subsystem B. A typical dissipative structure in the form of a tornado with a high degree of symmetry arises, but far from the state of thermodynamic equilibrium. Such structures are studied by the thermodynamics of nonequilibrium processes. For example, spiral waves in chemical reactions discovered and studied by Russian scientists B.N.Belousov and A.M. Zhabotinsky. Another example is the emergence of global zonal currents in the solar atmosphere. They get their energy from convective cells on a much smaller scale. Convection on the Sun occurs due to uneven vertical heating.

The lower layers of a star's atmosphere are heated much more strongly than the upper layers, which are cooled by interaction with space.

It is interesting to compare the figures obtained in the calculations with the observation data of the Florida tornado of 1935 class F-5, which was described by Ernst Hemingway in a pamphlet Who Killed Florida War Veterans?. The maximum wind speed in this tornado was estimated at 500 km / h, i.e. at 138.8 m / s. The minimum pressure measured by the Florida meteorological station has dropped to 560 mm Hg. Considering that the density of mercury is 13.596 g / cm 3 and the acceleration of gravity is 980.665 m / s 2, it is easy to obtain that this drop corresponds to the value of 980.665 * 13.596 * 56.9 \u003d 758.65 mbar. The pressure anomaly 758.65–1013.25 reached –254.6 mbar. As you can see, the agreement between theory and observations is good. This agreement can be improved by slightly varying the initial conditions used in the calculations. The connection of cyclones with a decrease in air pressure was noted back in 1690 by the German scientist G.V. Leibniz. Since then, the barometer has remained the simplest and most reliable instrument for predicting the beginning and end of tornadoes and hurricanes.

The proposed theory makes it possible to plausibly calculate and predict the evolution of tornadoes; however, it also raises many new problems. According to this theory, for the occurrence of a tornado, strongly rotating turbulent vortices are needed, the linear speed of rotation of which can sometimes exceed the speed of sound. Is there direct evidence of the presence of hypersonic vortices filling the emerging tornado? There are still no direct measurements of wind speeds in tornadoes, and these are exactly what future researchers should obtain. Indirect estimates of the maximum wind speeds inside a tornado give a positive answer to this question. They were obtained by experts in the strength of materials based on the study of the bending and destruction of various objects found in the tornado trail. For example, a chicken egg was punctured with a dry bean so that the shell of the egg around the hole remained intact, as in the case of a revolving bullet. Cases are often observed where small pebbles pass through the glass without damaging them around the hole. Numerous facts have been documented when flying boards pierced the wooden walls of houses, other boards, trees or even iron sheets. No brittle fracture is observed. They stick like needles into a pillow, straws or tree fragments into various wooden objects (chips, bark, trees, boards). The photo shows the bottom of the parent cloud from which the tornado is forming. As you can see, it is filled with rotating cylindrical turbulent vortices.

Large turbulent vortices are slightly smaller than the overall size of a tornado, but they can break up, increasing the speed of rotation by decreasing their size (like a skater on ice increases the speed of rotation by pressing his hands to his body). Huge centrifugal force throws out air from hypersonic turbulent vortices and a region of very low pressure arises inside them. There are many tornadoes and lightning.

Static electricity discharges are constantly generated by the friction of rapidly moving air particles against each other and the resulting electrification of the air.

Turbulent vortices, like the tornado itself, are very strong and can lift heavy objects. For example, a tornado on August 23, 1953 in the city of Rostov, Yaroslavl Region, lifted and threw aside a frame 12 m away from a truck weighing more than a ton. The incident with a 75 m long steel bridge rolled into a tight bundle has already been mentioned. Tornadoes break trees and telegraph poles like matches, rip from foundations and then tear apart houses to shreds, overturn trains, cut soil from the surface layers of the Earth and can completely suck up a well, a small section of a river or ocean, a pond or a lake, therefore, after tornadoes, rains are sometimes observed from fish, frogs, jellyfish, oysters, turtles and other inhabitants of the aquatic environment. On July 17, 1940, in the village of Meshchera, Gorky Region, during a thunderstorm, it rained from ancient silver coins of the 16th century. Obviously, they were recovered from a treasure buried shallowly in the ground and opened by a tornado. Turbulent vortices and downdrafts of air in the central area of \u200b\u200bthe tornado press people, animals, various objects, plants into the ground. The Novosibirsk scientist L.N. Gutman showed that in the very center of the tornado a very narrow and strong air stream directed downward can exist, and at the periphery of the tornado the vertical component of the average wind speed is directed upward.

Other physical phenomena accompanying tornadoes are also associated with turbulent eddies. The generation of a sound heard as hiss, whistles or rumblings is common in this natural phenomenon. Witnesses note that in the immediate vicinity of the tornado, the power of sound is terrible, but with distance from the tornado, it quickly decreases. This means that in tornadoes, turbulent vortices generate high-frequency sound, which quickly decays with distance, because the absorption coefficient of sound waves in air is inversely proportional to the square of the frequency and increases with increasing frequency. It is quite possible that strong sound waves in a tornado partially go beyond the frequency range of audibility of the human ear (from 16 Hz to 16 kHz), i.e. are ultrasound or infrasound. Measurements of sound waves in a tornado are absent, although the theory of sound generation by turbulent vortices was created by the English scientist M. Lighthill in the 1950s.

Tornadoes also generate strong electromagnetic fields and are accompanied by lightning. Ball lightning in tornadoes was observed repeatedly. One of the theories of ball lightning was proposed by P.L. Kapitza in the 1950s in the course of experiments on the study of the electronic properties of rarefied gases in strong electromagnetic fields of the ultrahigh frequency (microwave) range. In tornadoes, not only glowing balls are observed, but also glowing clouds, spots, rotating stripes, and sometimes rings. At times, the entire lower boundary of the mother cloud glows. Descriptions of light phenomena in tornadoes, collected by American scientists B. Vonnengut and J. Meyer in 1968 “Fireballs ... Lightning in the funnel ... Yellowish-white, bright surface of the funnel ... Continuous lights ... Column of fire ... Glowing clouds ... Greenish shine ... Luminous column ... Glitter in the form of a ring ... A bright glowing cloud of the color of a flame ... A rotating strip of dark blue ... Pale blue misty stripes ... Brick-red glow ... A rotating light wheel ... Exploding balls of fire ... Fire stream ... Luminous spots ... ". It is obvious that the glow inside the tornado is associated with turbulent vortices of various shapes and sizes. Sometimes the whole tornado glows with yellow light. Glowing columns of two tornadoes were observed on April 11, 1965 in Toledo, Ohio. American scientist G. Jones in 1965 discovered a pulsed generator of electromagnetic waves, visible in a tornado in the form of a circular light blue spot. The generator appears 30–90 minutes before the formation of the tornado and can serve as a prognostic sign.

Russian scientist L.G. Kachurin researched in the 70s of the 20th century. the main characteristics of the radio emission of convective cumulonimbus clouds forming thunderstorms and tornadoes. The studies were carried out in the Caucasus using an aircraft radar in the microwave range (0.1-300 megahertz), centimeter, decimeter and meter radio wave ranges. It was found that microwave radio emission occurs long before the formation of a thunderstorm. The pre-thunderstorm, thunderstorm and post-thunderstorm stages differ in the spectra of the radiation field strength, the duration and repetition rate of radio wave packets. In the centimeter range of radio waves, the radar sees the signal reflected from clouds and precipitation. In the meter range, signals reflected from the channels of strong lightning are clearly visible. In a record strong thunderstorm on July 2, 1976 in the Alan Valley in Georgia, up to 135 lightning discharges per minute were observed. The increase in the scale of lightning discharges occurred as the frequency of their occurrence decreased. In a thundercloud, zones with a lower frequency of discharges are gradually formed, between which the largest lightning strikes occur. LG Kachurin discovered the phenomenon of "continuous discharge" in the form of a continuous set of often following impulses (more than 200 per minute), the amplitude of which has an almost unchanged level, 4-5 times less than the amplitude of signals reflected from lightning discharges. This phenomenon can be viewed as “generators of long sparks” that do not develop into large scale linear lightning. The generator has a length of 4-6 km and slowly shifts, being in the center of a thundercloud - an area of \u200b\u200bmaximum thunderstorm activity. As a result of these studies, methods were developed for the operational determination of the stages of development of thunderstorm processes and the degree of their danger.

Strong electromagnetic fields in tornado-forming clouds can also serve for remote tracking of the path of tornadoes. M.A. Gokhberg discovered quite significant electromagnetic disturbances in the upper atmosphere (ionosphere) associated with the formation and movement of tornadoes. S.A. Arseniev investigated the magnitude of magnetic friction in tornadoes and put forward the idea of \u200b\u200bsuppressing tornadoes by dusting the parent cloud with special ferromagnetic filings. As a result, the magnitude of the magnetic friction can become very large and the wind speed in the tornado should decrease. Ways to deal with tornadoes are currently under study.

Sergey Arseniev

Literature:

D.V. Nalivkin Hurricanes, storms, tornadoes... L., Science, 1969
Vortex instability and the appearance of tornadoes and tornadoes... Moscow State University Bulletin. Series 3. Physics and Astronomy. 2000, no. 1
Arseniev S.A., Nikolaevsky V.N. The birth and evolution of tornadoes, hurricanes and typhoons... Russian Academy of Natural Sciences. Proceedings of the Earth Sciences Section. 2003, Issue 10
Arsenyev S.A., Gubar A.Yu., Nikolaevsky V.N. Self-organization of tornadoes and hurricanes in atmospheric currents with meso-scale eddies. Academy of Sciences reports... 2004, vol. 395, no. 6

Have you ever watched a column of dust or sand kicked up from the ground, like a dancing, wriggling whip? If so, rejoice - it was not a tornado. What you have seen is called a sandy or dusty whirlwind.


If you compare the danger it presents to the danger of a real tornado, it will be proportional to the danger of a toy tyrannosaur versus a living one. The energy contained in a true tornado is equivalent to the energy of a reference atomic bomb.

What is a tornado and where does it come from?

What is a tornado? We know it under various names - tornado, tornado, blood clot - and is one of the most dangerous natural phenomena. In essence, it is nothing more than a thundercloud that descended to the ground to "dance". The sweep of the "dance" at the surface of the earth can reach 3 kilometers, although it usually does not exceed 300-400 m.

What does a tornado look like? Like a huge funnel descending from heaven to earth. Around its lower part, a cloud of objects thrown by it, dirt, dust or water, if we are talking about a tornado over the water surface, is visible. Unlike the aforementioned sandy or dusty whirlwinds, the tornado is a single whole with - this is, one might say, its trunk descending to the ground. The tornado cannot tear itself away from it and become independent. Sand vortices have nothing to do with clouds at all.

The reasons for the appearance of tornadoes have not yet been properly studied. It is only known for certain that this natural phenomenon can occur if moist warm air comes into contact with the "dome" of cold dry air located above a cold area of \u200b\u200bland or sea.


The mechanism of occurrence is approximately the following: at the point of contact, the steam contained in the warm flow condenses, while heat is released, heating the air in the contact zone, and it naturally rushes upward. As you know, nature does not tolerate emptiness, and in its place warm humid air and cold air located below are drawn in ... And off we go. We have already compared a tornado with an atomic bomb. It turns out that they have not so little in common because what is happening cannot be called anything other than a chain reaction.

How is the notorious trunk that descends to the ground formed? The fact is that the cold air drawn into the rarefaction zone cools down even more and goes down. And with it, the rarefaction zone itself descends, which, having reached the bottom, begins to draw in everything that does not hit and lift it up.

The main danger of a tornado lies, firstly, in the fact that it can playfully raise a person to the very abyss of heaven, and then, having played enough, let it go in peace, and secondly, a section of rarefied air that has suddenly come to visit you can cause the fact that your house will explode "with joy" and fill you with debris.

What should be done in case of a tornado?

Hide. Reinforced concrete bunker - the most it! Climb into it - and you will not be afraid of any tornadoes! If you are in a car or some kind of trailer, get out immediately, otherwise you will feel like Ellie from The Wizard of the Emerald City. But with a ninety-nine percent probability, you can predict that things will not end so well.


If you managed to meet this monster in an open space, you can congratulate yourself on a record for bad luck: remember school physical education lessons and press the afterburner in the direction perpendicular to its movement. If this did not help and he did catch up with you (they sometimes spar at a speed of 60 km / h), become part of the landscape - squeeze into some depression, hollow, crack so that the area of \u200b\u200breduced pressure would not have the opportunity to tighten you. Indeed, this requires the forward movement of the air masses from the reverse side. Be sure to cover your head with your hands - you never know what "gift" will come from above.

If you are in a house that does not have a basement, take cover in the center of the room on the first floor. Stay away from windows. Doors and windows on the side of the approaching tornado must be closed, and on the opposite side, on the contrary, open and secured. This will avoid an explosion due to differential pressure. Cut off the electricity and turn off the gas.

How is a tornado different from a hurricane?

It often happens that a person does not really feel the difference between concepts such as hurricane and tornado. These are completely different things! A hurricane is a tropical cyclone that manifests itself as strong winds, thunderstorms and rainstorms.


Tornado - however, we have already described in detail what a tornado is. But, I must say, this confusion is not without reason - a hurricane can cause a tornado.

How is a tornado different from a tornado?

Nothing. It is often thought that a tornado and a tornado are different things. Nothing of the sort is synonymous. It's just that in some areas it is customary to call a tornado a land version of this phenomenon, and a tornado - a sea one.