The natural phenomenon of a tornado. Tornado (tornado). Description. The reasons. Interesting facts How a tornado is formed for children

I wanted to study the ordinary ones in more detail. For example, where do they come from, where they are most often found, and what kind of bizarre creatures of the indomitable elements are they.

It turns out that the fiery whirlwind is one of the varieties of whirlwinds that are found on Earth. And not only on Earth! By the way, some types of vortices are also found on other planets that have an atmosphere. But more about that later.

So, whirlwinds. Terrible and deadly destroyers, sweeping away everything in their path. Those of them that are born above the ground and above the water are called tornadoes or tornadoes. Water tornadoes are slightly different from their land-based counterparts. They are inferior to them in life expectancy, size and speed. But more about them later.

Generally tornado is an atmospheric vortex that occurs in a cumulonimbus cloud. It spreads downward, almost always reaching the surface of the earth. At the same time, the size of its diameter can vary from tens of meters to several kilometers. Interestingly, the shape of a tornado can be very diverse. They even came up with a classification.

Perhaps the most common classic version of a tornado that can be found is whip-like tornado. Its funnel looks very thin and almost smooth, while it can be quite sinuous. These tornadoes are perhaps the weakest. But do not underestimate their power, because such a whirlwind will destroy everything that it meets on the way. Another notable feature is that the width of the funnel is much less than its length.

The next type of funnel is called vague. It looks like a piece of a rapidly rotating cloud, which for some reason touches the ground. The diameter of these funnels is more than 0.5 kilometers and looks very blurry. These are very powerful whirlwinds, the action of which cannot be predicted. Such vortices are often composite.

So, what is a vortex with composite funnel? It turns out that such a death is the main, most powerful whirlwind, around which two or more separate whirlwinds revolve. Although the power of such tornadoes can vary, they usually represent one of the most powerful whirlwinds. Naturally, they cause enormous damage to large areas through which they passed.

There are also fire, sand and water whirlwinds.

It is noteworthy that the tornado consists of air and is not visible by itself. We see not the air, but the garbage, water and dust that he raised.

What are the reasons for the formation of a tornado? It turns out that, despite modern technology, scientists still have not been able to answer this question. Scientists at the moment could only characterize some common features that are inherent in almost all representatives of this genus.

Well, perhaps most significant, is that the existence of a tornado can be divided into three stages. The first stage, naturally, is the birth of the notorious whirlwind. During this period, a small funnel can be observed from a thundercloud. Then it gradually descends closer to the ground, sometimes increasing significantly. Cold layers of air that are under the cloud begin to fall down, displacing warmer ones. This is all quite normal, based on known physical laws. In this case, a collision of cold and warm fronts is formed, in which potential energy boldly passes into kinetic energy. Gradually, the speed increases, and, as a result, a tornado is born.

The second stage of the tornado's existence can be called its immediate life. The speed of the rotational movement of air increases with time, while in the center of the tornado, air flows rush to the top, forming an area of ​​low pressure, which is much less than the pressure of the environment. It is for this reason that the so-called tornado heart is the most dangerous. Buildings that hit the center of the tornado explode, people's organs can not stand it, and are torn apart. At the second stage, we see a vortex, the power of which is maximum. The tornado lives, moves in the direction it needs, sweeping away everything in its path.

At the third stage, as you probably already guessed, there is a gradual extinction of the vortex. He begins to gradually break away from the ground and eventually returns to where he came from - in his thundercloud.

It is noteworthy that the existence of each stage cannot be determined in any way. This can last from several minutes to several hours, which is very rare. The maximum recorded duration of the existence of a tornado is 7 hours and 20 minutes (Mattunsky tornado, 1917).

The speed of tornadoes also varies, but usually it ranges from 40 to 60 km / h. The maximum recorded speed is 210 km/h. At the same time, it is worth mentioning that the tornado does not move alone, but together with the cloud that gave rise to it. At the same time, during its existence, it can travel a distance that reaches 60 kilometers.

As for its height, it can reach one and a half kilometers.

Air in a tornado in our hemisphere usually rotates counterclockwise.

But scientists have problems with determining the speed of rotation inside a tornado. Due to the large destructive power, practically it is very difficult to calculate it. And because of the severe destruction associated with a sharp change in pressure, it is also difficult to theoretically assume what speed he had. It is believed that it exceeds 18 m/s and can reach 1300 m/s. But the information, unfortunately, is not accurate.

By the way, in the place where the funnel comes into contact with the ground, a so-called cascade can form. It is a column of dust and debris that a tornado will lift into the air. When a tornado is formed, you can observe such an interesting picture. Towards the whirlwind descending from the sky, a cascade rises from the ground, which seems to capture the lower part of the funnel. In this case, the cascade has a well-defined height. This is due to the fact that the debris that the tornado lifted into the air, reaching a certain height, can no longer be held by the tornado and fall. The funnel can also be surrounded by a case. Together, the case, the cascade and the tornado itself very often create an erroneous idea of ​​the width of the funnel. It appears to be much larger than it really is.

By the way, it turns out that a tornado and a tornado are the names of whirlwinds that rage in America. A tornado occurs over the sea, and a tornado over land. In Europe, they are usually called blood clots. But in the end, all three names of the terrible phenomenon are considered synonymous.

Many consider tornadoes to be one of the most violent natural disasters. And one cannot but agree with this.

It turns out that I classify tornadoes not only by the shape of the funnel, but also by power. The classification was introduced by Professor Teodoro Fujita in 1971 in the form of a scale. The scale was called the Fujita Scale or the Fujita-Pearson Scale. It is also called the F-scale. It consists of 13 categories from F0 to F12. Interestingly, theoretically, the speed of a tornado on the F12 scale can be equated to the speed of sound. The most common are tornadoes of the second and third categories. The categories above are practically non-existent.

The most massive simultaneous appearance of tornadoes of different power occurred in the United States in 1965. Then at the same time there were 37 tornadoes of different power. Naturally, the damage they caused to the six states was very significant. 3250 people were killed, and about 2.5 thousand were injured.

In Russia, tornadoes, although quite rare, still occur. For the first time they were mentioned in writing in 1406 in the Trinity Chronicle. Then the horse and its owner suffered.

A curious incident occurred in the village of Meshchery, which is located in the Gorky region. One day, grace descended on the inhabitants and it began to rain from the sky from silver coins. Unfortunately, the culprit of this grace turned out to be an ordinary tornado, which lifted into the air a treasure washed by rain near the village.

You can talk about tornadoes for a very long time. Indeed, despite the mortal danger, this is a very beautiful and interesting phenomenon. I will tell you about sand and water vortices in my next articles. That's all, perhaps.

All over the world and in all ages, tornadoes have arisen - amazing physical phenomena, when a furiously rotating funnel 1-2 km long and 50-100 m in diameter descends from a thundercloud. A tornado, as we see from the lines of the famous poetess, symbolizes something dark for a person , terrifying, destructive, dangerous. And this is no coincidence, it is known that the energy of a typical tornado with a radius of 1 km and an average speed of 70 m / s is equal to the energy of a reference atomic bomb of 20 kilotons of TNT, similar to the first atomic bomb exploded by the United States during the Trinity tests in New Mexico 16 July 1945 (according to S.A. Arsenyev, A.Yu. Gubar and V.N. Nikolaevsky). Having reached the Earth, the tornado with a roar and roar destroys everything in its path, and is able to cover a path of 500 km in 5-7 hours, sometimes increasing in diameter and leaving a strip of destruction 2 km wide. During the year, about 1000-1500 tornadoes occur on the globe, more than half of them in the USA.

1.1 Definition of the concept.

A tornado is an ascending whirlwind of extremely rapidly rotating air in the form of a funnel of enormous destructive power, in which moisture, sand and other suspensions are present. Ascending whirlwinds of rapidly rotating air, having the form of a dark column with a diameter of several tens to hundreds of meters with a vertical, sometimes curved axis of rotation. A tornado, as it were, "hangs" from the cloud to the ground in the form of a giant funnel, inside which the pressure is always low, so the effect of "suction" is manifested. The average wind speed is from 15-18 m / s to 50 m / s, the front width is 350-400 m. The length of the path is from hundreds of meters to tens and hundreds of kilometers. Sometimes tornadoes are accompanied by precipitation in the form of hail, heavy rain.

The form of tornadoes can be diverse - a column, cone, glass, barrel, whip-like rope, hourglass, "devil" horns, etc., but most often tornadoes have the form of a rotating trunk, pipe or funnel hanging from the parent cloud (hence their names are: tromb - in French pipe and tornado - in Spanish rotating).

Tornadoes exist from several minutes to several hours, and their largest trajectory is measured by several hundred kilometers. The width of the destruction zone corresponds to the size of the tornado itself, usually up to 2-3 km. The pressure difference between the center of the vortex and its periphery sometimes reaches 150-200 mb.

The movement of air in the system of tornadoes and tornadoes is usually counterclockwise, but clockwise movements are not excluded. At the same time, air rises in a spiral. In neighboring areas, air descends, as a result of which the vortex closes. Under the influence of a high rotation speed, a centrifugal force develops inside the vortex, due to which the pressure in it decreases. This leads to the fact that when the vortex moves into its system, everything that occurs on the way (water, sand or various objects: stones, boards, roofs of houses, etc.) is sucked in, which then fall out of the clouds, sometimes at a considerable distance. It is with this that the so-called colored or bloody rains are associated, which are formed by drawing colored rock particles into the vortex system and mixing them with raindrops. If a whirlwind occurs on a sea or lake, then it is called a tornado. Tornadoes often, along with water, suck fish into their system, which the cloud can throw out already on the shore.

Because the radius of the tornado funnel near the ground decreases, then the speed near the earth's surface reaches supersonic values. Inside the tornado, the rarefaction of the air is so great that the buildings crumble due to the pressure of the air in them. The ability of tornadoes to stick oblong objects (straws, sticks, debris, etc.) into trees, walls of houses, the ground, etc. is amazing.

The air pressure in cyclones is reduced, but in tornadoes the pressure drop can be very strong, up to 666 mbar at normal atmospheric pressure of 1013.25 mbar. The mass of air in a tornado rotates around a common center (“the eye of the storm”, where there is a lull) and the average wind speed can reach 200 m/s, causing catastrophic destruction, often with human casualties. Inside the tornado there are smaller turbulent eddies that rotate at a speed exceeding the speed of sound (320 m/s). Hypersonic turbulent eddies are associated with the most evil and cruel tricks of tornadoes and tornadoes, which tear people and animals apart or tear off their skin and skin.

Tornadoes rarely occur one at a time - more often in "families", several whirlwinds at a time. In some cases, "families" of several tens of eddies are created, hundreds of meters or even tens of kilometers apart from each other. The path of the tornado is intermittent: this happens when the "trunk" of the whirlwind breaks away from the ground to fall on it with new force. .

1.2 Reasons for the formation of tornadoes

The physical nature of the tornado has not been studied at all, there is no answer to the questions why it is stable, where it draws its energy from, why it is able, for example, to completely destroy a whole row of apple trees in the garden and leave apples hanging untouched on the apple trees of the neighboring row, etc. There was no agreement among researchers even on the issue of wind speed in a tornado: indirect evidence, such as straws stuck in logs and chips, spoke of supersonic speeds, and direct location measurements gave an unambiguous result - even for strong tornadoes, the speed is 300 km / h.

There are tornadoes and tornadoes as follows. From the central part of a powerful thundercloud, the lower base of which takes the form of an overturned funnel, a giant dark trunk descends, which stretches towards the surface of the Earth or the sea. Here, a wide funnel of dust or water rises towards him, into the open bowl of which the trunk, as it were, plunges its end. A continuous column is formed, moving at a speed of 20-40 km / h. The narrowest part of this column falls approximately in the middle, its height reaches 800-1500 m. Several tornado funnels can descend from a thundercloud.

Tornadoes go through three main stages in their development. At the initial stage, an initial funnel appears from a thundercloud, hanging above the ground. Cold layers of air 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 join - warm and cold). The potential energy of this system is converted into the kinetic energy of the rotational movement of air. The speed of this movement increases, and it takes on its classic form.

The rotational speed increases with time, while in the center of the tornado, the air begins to intensively rise upwards. This is how the second stage of the existence of a tornado 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 away from the surface of the earth, gradually rising back into the parent cloud.

The speed of tornadoes also varies, on average - 40 - 60 km / h (in very rare cases it can reach 210 km / h). .

There are two types of tornadoes by origin: tornadoes, which were caused by severe thunderstorms, and tornadoes, which appeared as a result of other factors. As a rule, tornadoes appear as a result of thunderstorms and are often the most dangerous. A superstorm is a prolonged (more than one hour) thunderstorm that continues due to an upward air flow, inclined and constantly rotating. This stream is 10 miles wide and 50,000 feet high and takes 20 to 60 minutes to form a tornado. Scientists call this rotation a mesocyclone when it is detected on Doppler radar. Tornadoes are an extremely small part of this large-scale circulation. The most powerful tornadoes result from severe thunderstorms.

Tornadoes of the second type are formed without the participation of ascending swirling air currents. Such a tornado is a whirlwind of dust and debris that forms near the very surface of the earth, along the front line of the wind without that terrible spinning funnel. Another version of a tornado is a tornado, or otherwise a hurricane. This phenomenon is characterized by a narrow rope-shaped funnel that forms when a thundercloud is still forming and there is no upward swirling airflow. A water tornado is similar to a "land tornado", only it occurs above the water.

The most favorable environment for the origin of the funnel is fulfilled when three conditions are met. First, the mesocyclone must be formed from cold, dry masses of air. In this case, a particularly large temperature gradient close to the adiabatic value arises along its height. Secondly, the mesocyclone should enter the area where a lot of moisture has accumulated in the surface layer 1-2 km thick at a high air temperature of 25-35 ° C, i.e. a state of instability of the surface layer is created, ready for the formation of cells with ascending and descending flows. Passing over these areas, in a short time, the mesocyclone sucks in moisture from large spaces and throws it to a height of 10-15 km. The temperature inside the mesocyclone rises abruptly over the entire height due to the heat brought by moisture, accumulated not only by saturated steam, but also by water droplets. The third condition is the ejection of masses of rain and hail. The fulfillment of this condition leads to a decrease in the flow diameter from the initial value of 5–10 km to 1–2 km and an increase in velocity from 30–40 m/s in the upper part of the mesocyclone to 100–120 m/s in the lower part.

1.3 Places of formation of tornadoes

Atmospheric whirlwinds, similar to tornadoes, but formed in Europe, are called blood clots, and in the USA - tornadoes. Tornadoes and tornadoes, like tropical cyclones, are generated in the presence of a large supply of instability energy in the atmosphere. These conditions are created when there is very warm and humid air below, and cold air in the upper troposphere.

Thunderstorms occur in most of the world, with the exception of regions with a subarctic climate and an arctic climate, however, tornadoes can accompany only those thunderstorms that are at the junction of atmospheric fronts.

The largest number of tornadoes is recorded on the North American continent, especially in the central states of the United States, less - in the eastern states of the United States. There are about 200 of them a year. The speed of the tornado is also high, sometimes it reaches 100 km/h. In southern North America, tornadoes occur throughout the year, with a maximum in the spring and a minimum in the winter.

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

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

Tornadoes are also recorded in the east of Argentina, South Africa, the west and east of Australia and a number of other regions, where there may also be conditions for the collision of atmospheric fronts.

1.4 Classification of tornadoes

scourge-like

This is the most common type of tornadoes. The funnel looks smooth, thin, and can be quite tortuous. The length of the funnel considerably exceeds its radius. Weak whirlwinds and whirlpools that descend on the water are, as a rule, whip-like whirlwinds.

vague

They look like shaggy, rotating clouds reaching the ground. Sometimes the diameter of such a tornado even exceeds its height. All craters of large diameter (more than 0.5 km) are indistinct. Usually these are very powerful whirlwinds, often compound ones. They cause enormous damage due to their large size and very high wind speeds.

Composite

Composite tornado in Dallas 1957

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 vast areas.

fiery

These are ordinary tornadoes generated by a cloud formed as a result of a strong fire or volcanic eruption. It is these tornadoes that were first artificially created by man (the experiments of J. Dessen (Dessens, 1962) in the Sahara, which continued in 1960-1962).

According to the intensity and degree of destruction, tornadoes are divided into seven categories:

1. Wind speed 18-32 m/s. Weak destruction: chimneys, fences, trees are damaged.

2. Wind speed 33-49 m/s. Moderate destruction: roof coverings are torn off, moving vehicles are thrown off the road.

3. Wind speed 50-69 m/s. Significant destruction: roofs are ripped off houses, trucks are overturned, trees are uprooted.

4. Wind speed 70-92 m/s. Severe destruction: roofs and part of the walls are destroyed, wagons are overturned, most of the trees in the forest are uprooted, rise above the ground and heavy vehicles move.

5. Wind speed 93-116 m/s. Devastating destruction: heavy buildings are destroyed, buildings with weak foundations are moved to another place, cars are scattered to the sides, large objects are carried in the air.

6. Wind speed 117-142 m/s. Super-destructive destruction: heavy buildings are lifted, cars are carried and destroyed, huge objects travel through the air for long distances at high speed, trees are broken into pieces.

7. Wind speed from 143 m/s to the speed of sound and more. Complete destruction.

In Western meteorology, the intensity of tornadoes (tornadoes) is estimated on the Fujita-Person scale, named after the scientists who studied this phenomenon. According to this scale, the intensity is estimated by three indicators: wind speed in a tornado F, the length of the traveled path L and the width of the destruction zone W ..

Tornadoes and tornadoes are considered the most dangerous natural disasters for all living beings. The tornado has been thoroughly studied, but no one has yet learned how to escape and pacify this disaster. According to scientists, tornadoes occur every year and their number is steadily increasing. The reason for this may be constant climate change, as well as the deterioration of the planet's ecology.

Every creature and object that gets there, after a while, will be thrown from a huge height and in a completely different place. Also, objects that have flown from a tornado are of great danger. Even houses are not protected, strong air currents can easily demolish a building, dragging a lot of debris inside.

What does the word "tornado" mean?

Most of the phenomenon occurs in North American territories. It is from there that disasters take their name. In Spanish, "tornado" means "revolving". Wind vortices became known as tornadoes by the Spanish colonists who arrived to conquer new territories.

In the territories of Russia, the phenomenon was called a habitual tornado. The word comes from the old Russian "smurch" or "smrch", which means a cloud. Thus, the concepts of "tornado" and "tornado" are synonymous. They describe the same phenomenon.

Interesting fact: once a case was recorded when a heavy train weighing 80 tons was carried away by a whirlwind. The whirlwind pulled him 40 meters off the tracks.

What is a tornado and tornado?

Most tornadoes occur in thunderclouds. They are atmospheric whirlwinds that stretched from heaven to earth. Air masses are in constant motion, forming a funnel that sucks in any object in its path. The internal currents of the tornado are attracted to the surface, while the external ones rise up. Thus, inside the tornado, the air is highly discharged.

All objects that fall inside a tornado can explode from the simultaneous impact of different pressures. Basically, such objects are considered closed buildings. The tornado spares no one.

Tornadoes (or huge tornadoes) are considered one of the most terrible and destructive phenomena of the nature of our planet. They are a narrow, rotating at a monstrous speed, a column of air that stretches from the ground to a thundercloud. Since the wind is invisible, we cannot see the tornado, so to speak, in its purest form. We can judge its presence, movement and power only by its visible signs, namely, by the funnel, which consists of water drops and various objects rising up from the surface of the earth. The dust and debris in this spinning funnel also makes the location of the tornado visible.

Tornadoes are a formidable natural phenomenon.

Usually tornadoes and tornadoes are formed during a severe thunderstorm and they represent the greatest danger. An extremely fast spinning wind can cover enormous distances in very short time intervals, which means the possibility of large-scale destruction on a huge area in an extremely short time. Tornadoes have accounted for more than one hundred human lives, and have also brought material losses for many billions of dollars.

Tornadoes are a formidable natural phenomenon.

Scientists recorded the highest speed of a tornado on April 2, 1958 in the small town of Wichita Falls in the USA, it was approximately four hundred kilometers per hour. The consolation is the fact that only two percent of tornadoes can reach this power. However, about seventy percent of them lead to terrible tragedies and many human casualties.

Sometimes it happens that in one place not one, but several tornadoes form at once. For example, on March 28, 1984, as many as twenty-two tornadoes formed in a short period of time in the states of North and South Carolina. Almost sixty people became victims of this element, more than a thousand were injured, and the damage to the economy as a result of destruction amounted to about two hundred million US dollars. The very next year, in the states of Ohio, Ontario and Pennsylvania, more than forty tornadoes were registered, killing almost eighty people and seriously maiming and injuring another thousand. The economic damage was estimated at almost half a billion dollars.
In general, about a thousand tornadoes of various strengths and speeds are recorded in the United States annually, but only a small percentage of them harm populated buildings. It is very unlikely that the elements will hit the building where you are, but you can further reduce the risk of injury by following a few simple tips.
The main thing is not to panic, not to lose vigilance if, judging by all the signs, a tornado begins. For those who are in open areas, it is best to find shelter in the form of a ravine, a hollow and wait out the elements there. If you are in a building, you need to choose the safest place there, for example, in a doorway, under a sturdy table and cover yourself with something soft, like a mattress.

Every year, tornadoes and tornadoes claim the lives of about sixty people. People mostly die and get injured from falling debris, which a terrible wind lifts up, and then, weakening, throws them on the heads of the unfortunate. The most terrible tornado in history, which killed almost seven hundred people, was the tornado that swept on March 18, 1925 over the states of Missouri, Indiana and Illinois. He walked the longest distance, over two hundred miles.

It is not yet possible for a person to cope with such a destructive force, it is difficult to predict the appearance of such a terrible phenomenon, so if you live in an area with a high probability of a tornado, be prepared and know how to protect yourself from it.

What is a tornado?

A tornado is one of the most dangerous weather phenomena. Fortunately, it appears quite rarely, so many people know what a tornado is, but few have seen it. A tornado is a whirlwind of air that is formed from clouds and stretches down. Outwardly, a tornado looks like a funnel, which expands more and more with increasing intensity. This dark column can reach several tens of meters in diameter. Below, the column also turns into a funnel, and it consists of dust, water, objects that are picked up by this terrible phenomenon.

Tornado, why is he dangerous?

If you do not understand why a tornado is dangerous, then just imagine that inside the funnel the air speed reaches 300 kilometers per hour. A tornado can cause truly terrible destruction along its entire path. What is amazing, literally a few meters from the tornado's lane, there is complete silence. For example, in one city, a tornado can destroy everything in its path, and in the suburbs of this city, a dark pillar will not even be visible. A tornado is especially dangerous because no one can predict for sure where and when this deadly funnel will appear. There were cases when a tornado destroyed and raised concrete bridges, cars and entire houses into the air.

How to distinguish between a tornado and a tornado?

If you did well in school, you should know how a tornado differs from a tornado. A tornado appears only over land, that is, it is formed from dust and ground objects. As for the tornado, it occurs over water. The coast of the United States suffers especially often from such climatic disasters. Fortunately, in our latitude it is very rare to witness such a phenomenon, but you can see what a video tornado is, since almost every person now has the Internet.

Such a number of tornadoes and tornadoes throughout the globe is explained by the large amount of energy that, under certain conditions, can accumulate in low atmospheric layers. This happens especially often in hot weather.

Any tornado or tornado is always destruction and tragedy for many people. With each appearance of such a climatic cataclysm, people suffer, as a tornado lifts their houses and cars from the ground. There were cases when even people fell into the funnel. The famous soothsayer Vanga said that as a child she fell into the funnel of a steppe tornado.

Many people do not understand the danger posed by tornadoes and tornadoes, they consider all this to be just a beautiful phenomenon. Indeed, it is very beautiful, but only from the outside. It is categorically not desirable to approach such phenomena, since no one can predict in which direction the funnel will move at the next moment. Therefore, it is better to watch the video at home and be glad that the tornado has not visited your house yet.