What is a hurricane and why Harvey is so dangerous: nature's fury. What is the difference between a tornado and a tornado? What is stronger - a tornado or a tornado? What is stronger than a typhoon or a storm?

Air-mechanical foam (AMF). It is a mixture of air, water and foaming agent. It can be ordinary - 90% air and 10% aqueous solution of a foaming agent (multiplicity up to 12%) and high expansion - 99% air, about 1% water and 0.04% foaming agent (multiplicity 100% or more). The durability of air-mechanical foam is somewhat less than that of chemical foam. Durability decreases with increasing foam ratio. The fire extinguishing effect of air-mechanical foam is based on thermal and moisture insulation and cooling of flammable substances. On the surface of burning liquids, foam forms a stable film that does not collapse under the influence of flame for 30 minutes, which is enough to extinguish flammable and flammable liquids in tanks of any diameter. Air-mechanical foam is completely harmless to people, does not cause metal corrosion, is practically electrically neutral and very economical. It is also used to extinguish solid flammable substances - such as wood, chemical fibers and others.

Extinguishing with inert gases. Inert gases (002 and Nz) and water vapor have the property of quickly mixing with flammable vapors and gases, thereby reducing the oxygen concentration, helping to stop the combustion of most flammable substances. The fire extinguishing effect of inert gases and water vapor is also explained by the fact that they dilute the flammable medium, thereby reducing the temperature at the source of the fire, as a result of which the combustion process becomes difficult.

Carbon dioxide is widely used to accelerate the elimination of the source of combustion (within 2-10 seconds), which is especially important when extinguishing small-area surfaces of flammable liquids, internal combustion engines, electric motors and other electrical installations, as well as to prevent ignition and explosion during storage of flammable materials. liquids, production and transportation of combustible dusts (for example, coal). To extinguish fires with carbon dioxide, automatic stationary installations, as well as manual mobile and portable fire extinguishers are used. Solid fire extinguishing agents. To eliminate small fires of substances that cannot be extinguished with water and other fire-neutralizing agents, solid substances in the form of powders are used. These include chlorides of alkali and alkaline earth metals (fluxes), albumin-containing substances, dry residue from the evaporation of sulfate alkalis, carnallite, bicarbonate and carbon dioxide soda, potash, quartz, solid carbon dioxide, sand, earth and others. The fire extinguishing effect of powdered substances lies in the fact that when they melt, accompanied by the formation of a film, their mass isolates the fire zone, impedes the access of air to it, cools the flammable substance, and mechanically knocks down the flame. You should have at least 1-2 shovels near the place where they are stored.

The choice of certain fire extinguishing installations or other fire extinguishing means is determined in each individual case, based on the specific stage of fire development, the scale of combustion and the characteristics of the combustion of substances and materials. Foam installations are widely used in enterprises where flammable liquids with a vapor flash point above 28°C and solid combustible materials and products (chemical fibers) are stored and processed. To extinguish fires at the initial stage, you can use asbestos or felt cloth, which, when tightly covering the burning object, prevents air from entering the combustion zone.

Fire extinguishers are an effective means of extinguishing a small fire. Intermittent powder (OP) fire extinguishers are designed to extinguish fires of gasoline, diesel fuel, varnishes, paints and other flammable liquids, as well as electrical installations under voltage up to 1000 V. Cylinder capacity - 2, 5 and 8 l, duration of jet output - 10-25 seconds, extinguishing area -0.41-1.1 m2 Carbon dioxide fire extinguishers (CO) are used to extinguish fires of various substances and materials at ambient temperatures from -25 up to +50° C, as well as live electrical equipment. Cylinder capacity - 2, 5 and 8 liters. The charge of carbon dioxide fire extinguishers by weight is checked once every 3 months. Weight loss should not exceed 10%. Charging is carried out in special workshops. Their validity period is 5 years less than that of powder fire extinguishers. Air-foam fire extinguishers (AFF) are used to extinguish fires of liquid and solid substances and materials, with the exception of alkali and alkaline-earth materials and their alloys, as well as to extinguish fires of live electrical equipment. Used at temperatures from +5 to +50° C. Cylinder capacity - 5 and 10 l, jet length - from 3 to 4.5 m, duration of action - 20-45 s, extinguishing area - 0.4 -0.5 m2 For To achieve the greatest efficiency of fire extinguishers, it is necessary to bring them into working condition near the place of combustion, so as not to lose extinguishing agents, but to act quickly, since they work for a short time (foam 20-45 s, carbon dioxide 15-25 s, powder 10-25 s ). When extinguishing solid substances and objects, foam fire extinguishers direct the stream to the places of the most intense burning, gradually knocking down the fire from top to bottom. They begin to extinguish the spilled liquid from the edges, gradually covering the burning surface with foam. When extinguishing burning substances with powder fire extinguishers, the entire surface should be covered with powder. Powder fire extinguishers can be used to extinguish a TV, even if it is plugged in. To extinguish the engine of a car, automatic aerosol extinguishing installations have been created, which are installed under the hood of the car. Chemical-foam fire extinguishers OKHP - 10, chemical air-foam fire extinguishers OKVP - 10 are used when extinguishing flammable materials, with the exception of live electrical installations. The principle of their operation is based on the interaction of the acidic part of the charge (aqueous solution of sulfuric acid salt) and the alkaline part (aqueous solution of sodium bicarbonate) with the formation of carbon dioxide and foam. The fire extinguisher OKVP-10 differs from OKHP-10 in the composition of the charge and an additional nozzle for the formation of air-mechanical foam.

What is the difference between a hurricane and a storm?

There are different types of storms, but they all have one thing in common: they are basically the rapid movement of air from one place to another.

A storm during which it rains, thunder rumbles and lightning flashes is called a thunderstorm, or lightning storm. If the wind raises a large amount of dust along the road, then such a storm is called a dust storm. A storm at sea is a storm. The most dangerous and destructive types of storms are hurricanes and tornadoes.

Hurricanes are storms that originate in tropical latitudes. For example, in North America they most often take place in the Gulf of Mexico, then rolling along the entire eastern coast of the continent. Exactly the same storms hit... islands and coasts in the Far East and in the China Sea, but there they are called typhoons. The common name for both types is tropical storm.

As a rule, a hurricane covers an area with a diameter of 150 to 600 km, and the wind speed reaches from 120 to 200 km/h. A distinctive feature of hurricanes is a calm spot at the very center, called the eye of the hurricane. Its size ranges from 5 to 20 km in diameter. When a person enters this zone, it begins to seem to him that the hurricane is over. However, as soon as the “eye” of the hurricane moves further, the wind rises with no less force, although it blows in the opposite direction than before. This is because a hurricane is an annular storm. In other words, the winds blow in a circle as the hurricane moves forward.

Our planet is beautiful, and people consider themselves rightful masters on it. They changed her face like nothing else before the beginning of human life. But there are forces that simply cannot be controlled, even using the highest technologies. These include hurricanes, storms, tornadoes, which constantly destroy everything that is dear to people. And it is impossible to stop it. You can only hide and wait for the end of nature’s wrath. So how do these phenomena occur and what consequences do the victims face? The answers to these questions have long been given by scientists.

Hurricane

A hurricane is a complex weather phenomenon. Its main characteristic is a very strong wind, with a speed of more than 30 meters per second (120 km/h). Its second name is typhoon, which is a huge whirlwind. The pressure in the very center is reduced. Forecasters also clarify that a hurricane is a tropical cyclone if it formed in South or North America. The life cycle of this monster lasts from 9 to 12 days. At this time, he moves around the planet, causing damage to everything he comes across. For convenience, each of them is assigned a name, most often a female one. A hurricane is, among other things, a huge clot of energy, which in its power is not inferior to an earthquake. One hour of the vortex's life releases about 36 megatons of energy, as in a nuclear explosion.

Causes of hurricanes

Scientists call the ocean the constant source of this phenomenon, namely those areas that are located in the tropics. The likelihood of a hurricane increases as you approach the equator. There are many reasons for its appearance. It could be, for example, the force with which our planet rotates, or differences in temperature between layers of the atmosphere, or differences in atmospheric pressure. But these processes may not be the beginning of a hurricane. Another of the main conditions for the formation of a typhoon is a certain temperature of the underlying surface, namely water. It should not be below 27 degrees Celsius. This shows that in order for a hurricane to form at sea, a combination of favorable factors is needed.

Storm

A storm is also characterized by strong winds, but its speed is lower than that of a hurricane. The speed of wind gusts in the storm is 24 meters per second (85 km/h). It can pass both over the water areas of the planet and over land. It can be quite large in area. The duration of a storm can be a couple of hours or several days. At this time there is very heavy rainfall. This leads to additional destructive phenomena such as landslides and mudflows. This phenomenon is located at a level lower than a hurricane on the Beaufort scale. A storm at its most extreme can reach force 11. The storm that was recorded in 2011 is considered the strongest. It passed over the Philippine Islands and caused thousands of deaths and millions of dollars worth of destruction.

Classification of storms and hurricanes

Hurricanes are divided into two types:

Tropical - those that originated in the tropics;

Extratropical - those that originated in other parts of the planet.

Extratropical ones are divided into:

• those that originated in the Atlantic Ocean region;
• those that originate over the Pacific Ocean (typhoons).

There is no classification of storms that would be considered generally accepted yet. But most weather forecasters divide them into:

Vortex formations are complex formations that arise due to cyclones and cover a large area;

Stream storms are small storms of a local nature.

A whirlwind storm can be snowy, dusty or squally. In winter, such storms are also called blizzards or blizzards. Squalls can occur very quickly and end just as quickly.

A flow storm can be a jet or a katabatic storm. If it is a jet, then the air moves horizontally or rises along a slope, and if it is a runoff, then it moves down a slope.

Tornado

Hurricanes and tornadoes very often accompany each other. A tornado is a vortex in which air moves from bottom to top. This happens at extremely high speed. The air there is mixed with various particles such as sand and dust. This is a funnel that hangs from a cloud and rests on the ground, somewhat similar to a trunk. Its diameter can vary from tens to hundreds of meters. The second name for this phenomenon is “tornado”. As it approaches, a terrible roar is heard. As the tornado moves, it sucks in everything it can tear off and lifts it up in a spiral. If this funnel appears, then it is a hurricane of terrible proportions. A tornado can reach speeds of about 60 km/h. It is very difficult to predict this phenomenon, which worsens the situation and leads to large losses. Hurricanes and tornadoes have claimed many lives throughout the history of their existence.

Beaufort scale

Hurricanes, storms, tornadoes are natural phenomena that can occur anywhere on Earth. In order to understand their scale and be able to compare them, a measurement system is needed. For this, the Beaufort scale is used. It is based on a visual assessment of what is happening and measures the wind strength in points. It was developed in 1806 for his own needs by a native of England, Admiral F. Beaufort. In 1874 it became generally accepted and has since been used by all weather forecasters. It was further clarified and supplemented. The points in it are distributed from 0 to 12. If 0 points, then this is complete calm, if 12 is a hurricane, bringing with it severe destruction. In 1955, the USA and England added 5 more points to the existing ones, that is, from 13 to 17. They are used by these countries.

Verbal indication of wind force	Points	Speed, km/h	Signs by which you can visually determine wind strength
Calm	0	Up to 1.6	On land: calm, smoke rising without deviation. At sea: water without the slightest disturbance.
Quiet	1	From 1.6 to 4.8	On land: the weather vane is not yet able to determine the direction of the wind; it is noticeable only by a slight deflection of the smoke. At sea: small ripples, no foam on the crests.
Easy	2	From 6.42 to 11.2	On land: the rustling of leaves is heard, ordinary weather vanes begin to react to the wind. At sea: the waves are short, the crests are like glass.
Weak	3	From 12.8 to 19.2	On land: large branches sway, flags begin to develop. At sea: the waves, although short, are well defined, with crests and foam, and occasionally small whitecaps appear.
Moderate	4	From 20.8 to 28.8	On land: sawdust and small debris fly in the air, thin branches begin to sway. At sea: the waves begin to lengthen, a large number of whitecaps are recorded.
Fresh	5	From 30.4 to 38.4	On land: trees begin to sway, ripples appear on bodies of water. At sea: the waves are long, but not too big, with a lot of whitecaps, and occasional splashes.
Strong	6	From 40.0 to 49.6	On land: thick branches and electrical wires sway to the sides, the wind tears the umbrella out of your hands. At sea: large waves with white crests form, splashes become more frequent.
Strong	7	From 51.2 to 60.8	On land: the whole tree, including the trunk, sways, making it very difficult to walk against the wind. At sea: the waves begin to pile up, the crests break off.
Very strong	8	From 62.4 to 73.6	On land: tree branches begin to break, it’s almost impossible to walk against the wind. At sea: the waves are getting higher, the spray is flying up.
Storm	9	From 75.2 to 86.4	On land: the wind begins to damage buildings, removing roof coverings and smoke hoods. At sea: the waves are high, the crests capsize and create spray, which significantly reduces visibility.
Heavy storm	10	From 88.0 to 100.8	On land: a rather rare occurrence; trees are uprooted and poorly fortified buildings are destroyed. At sea: the waves are very high, foam covers most of the water, the waves hit with a strong roar, visibility is very poor.
Hard Storm	11	From 102.4 to 115.2	On land: rarely occurs, causes great destruction. At sea: waves of enormous height, small and medium-sized ships are sometimes not visible, the water is all covered with foam, visibility is almost zero.
Hurricane	12	From 116.8 to 131.2	On land: extremely rare, causes enormous destruction. At sea: foam and spray fly in the air, visibility is zero.

Why is a hurricane scary?

One of the most dangerous meteorological phenomena can be called a hurricane. The wind moves at great speed in it, causing great harm to people and their property. In addition, these air currents carry with them dirt, sand and water, which leads to mudflows. Huge downpours cause floods, and if it happens in winter, avalanches often occur. Strong winds destroy structures, tear out trees, overturn cars, and blow people away. Very often, fires and explosions occur due to damage to electrical networks or gas pipelines. Thus, the effects of a hurricane are dire, making them very dangerous.

Hurricanes in Russia

Hurricanes can threaten any part of Russia, but most often they occur in the Khabarovsk and Primorsky territories, Kamchatka, Sakhalin, Chukotka or the Kuril Islands. This misfortune can happen at any time, and August and September are considered the most dangerous. Forecasters are trying to anticipate such recurrence and warn the population about the danger. Tornadoes may also appear on the territory of the Russian Federation. The most susceptible to this phenomenon are the water areas and sea coasts, Siberia, the Urals, the Volga region and the central regions of the state.

Actions of the population in case of a hurricane

Every person should understand that a hurricane is a deadly phenomenon. If there is a warning about it, you need to act quickly. The first step is to strengthen everything that can be torn off the ground, remove fire hazards and stock up on food and clean water for a couple of days ahead. You also need to move away from the windows; it is better to go to where there are none at all. Electricity, water and gas equipment should be turned off. Candles, lanterns and lamps are used for lighting. To receive weather information, you need to turn on the radio. If you follow these recommendations, your life will not be in danger.

Thus, hurricanes are distributed throughout the globe, making them a problem for all people. It should be remembered that they are extremely dangerous, so you must strictly follow all instructions in order to save your life.

Emergencies such as natural disasters pose a grave threat to all living things. Often they arise completely suddenly, catching a person by surprise. Natural phenomena that occur as a result of sudden changes in pressure in the atmosphere include tornadoes and hurricanes. Fortunately, most of us have not had to come close to the mentioned elements. Therefore, their scale and destructive power are not known to everyone. In this article we will tell you how a tornado differs from a hurricane.

Definitions

Tornado- an atmospheric vortex that arises in a thundercloud and descends. Often it reaches the very surface of the earth. It looks like a trunk or cloud sleeve, the diameter of which covers tens and sometimes even hundreds of meters. Such a natural phenomenon that forms over the surface of the water is often called a “tornado.” But in general there is no fundamental difference between the two definitions. Tornado and tornado are synonymous words. The term itself comes from the Old Russian “smrch”, which means “cloud”. The longest disaster recorded in the United States was in 1917. In almost 7.5 hours, the whirlwind covered a distance of 500 km and caused the death of 110 people. Often, a tornado is hidden behind a layer of rain and dust, making it difficult for meteorologists to recognize it in a timely manner.

Tornado

Hurricane– a strong wind, the speed of which can reach 120 kilometers per hour. The strength of the element is determined on a 12-point scale. The scale of this natural phenomenon is comparable to an earthquake. It covers a vast territory and lasts several days. According to the observations of scientists, hurricanes occur mainly at the end of summer. At this time, the already fairly heated water begins to evaporate intensively. Cold currents come from the bottom, creating a vortex several tens of kilometers wide on the surface. Moreover, at the epicenter of the funnel the weather remains absolutely calm, while wind and storm rage at the edges. Gradually, the hurricane moves to land, where it loses its strength within a few days. In Russia, disasters of a similar scale were observed in Chukotka, Kamchatka and Sakhalin, as well as in the Primorsky and Khabarovsk territories.

Hurricane

Comparison

To begin with, we note that both phenomena under consideration represent rapid wind movement in a certain direction. They can safely be called atmospheric vortices. However, while a tornado originates in the sky, a hurricane originates in the sea. The funnel of the first does not exceed 3 km in diameter. The average speed of the storm is from 20 to 60 km per hour. As for the duration of the phenomenon, the maximum duration of its activity is only a few hours. A hurricane is a much larger disaster in terms of area coverage. Moving at a speed of 120-200 km per hour, it affects huge areas. The life cycle of a natural phenomenon is on average 9-12 days. The diameter of the epicenter of the disaster ranges from 5 to 20 km.

Perhaps the main difference between a tornado and a hurricane is the volume of its destruction. Despite the relatively small diameter of the funnel, the first phenomenon has simply unimaginable power. It is capable of lifting upward an object whose weight reaches several tons. An area of ​​extremely rarefied air is created in the center of the funnel. Objects caught in it, including houses, can simply explode from the inside. Within the radius of the tornado's passage, nothing remains intact. Whereas at the epicenter of a hurricane there is a so-called eye - an area of ​​calm with moderate winds. While in it, a person may mistakenly think that the disaster has subsided. However, at the moment the hurricane moves, the wind will play out with renewed vigor, blowing in the opposite direction. It tears off roofs from houses, breaks windows, lifts cars and other objects into the air, etc. Buildings often remain standing in place.

Let's summarize what is the difference between a tornado and a hurricane.

Unbridled natural phenomena. It is impossible to prescribe rules of conduct for a tornado or hurricane, or to direct a typhoon or tornado along the desired path. There are even scientific developments of these weapons, against which humanity is powerless.

But, until now, these phenomena have not been fully studied, which is why they are dangerous. And, and for all living things.

website - Let's dream together about indomitable and unbridled tropical destroyers.

Christopher Columbus first mentioned this in his notes back in 1495.

A tropical cyclone is formed due to pressure changes over water surfaces. Humid and hot air rushes upward, condenses, and thereby receives incredible energy, moving in a spiral. And it pours out onto the ground in the form of precipitation.

They occur mainly in tropical latitudes, hence their name.

It is believed that W. Shakespeare “legitimized” the spelling of the word hurricane.

The largest hurricane can be compared in size with the state

1. These unbridled phenomena are capable of producing so much energy in one day that it is quite enough to illuminate the streets of a large metropolis for several years.
2. One small “brawler” dumps 9 trillion liters of precipitation per day (rain and rain).
3. The hurricane dumps tens of tons on the beaches. Many waterfowl who died under the influence of the enormous pressure of the elements had their eyes gouged out.
4. The direction of its rotation depends on the hemisphere in which it originated. In the South they rotate in the clockwise direction and, accordingly, in the North they rotate in the opposite direction.
5. More powerful cyclones and typhoons occur in the North, with the movement "against".

Showers, tornadoes, huge waves and storm surges retain their power only over the surface of seas, oceans and large bodies of water. When approaching land, they instantly lose their strength and subside.

If you make associations: a tornado is as wide as a hot dog, and a hurricane is as wide as a football field in a stadium

1. If we consider only the last 200 years, there were almost 2 million human casualties from such disasters around the world.
2. Hurricanes and typhoons “reach” beaches when its center crosses the coastline.
3. The largest hurricane can be compared to the size of a state. Up to 1000 km in diameter. Average size up to 350 km.
4. Such phenomena never occur at the equator. This happens because they need the Coriolis force for rotation (inertial force), and in this place it is the weakest on the planet.
5. Oddly enough, but these are an important and integral part of the weather system of our planet. Typhoons, tornadoes and hurricanes transport huge masses of hot, humid air from the tropics to the poles. Balancing humidity and temperature in the Earth's atmosphere. In their absence, part of the animal world would simply die out from heat and drought.

“Hurricanes are like people. Every storm has the characteristics of a living creature..." Desmond Bagley

The eye is the center of the cyclone

Why are hurricanes given female names?

Until 1953, they were given names completely haphazardly. By numbers or by the first letters of the alphabet. After this year, the World Meteorological Organization decided to give them easy-to-pronounce female names.

US military weather forecasters did this jokingly, in honor of the indomitable temper of their mothers-in-law and wives. This tradition has become part of the system. Nowadays, male names are sometimes used. Cyclones Bob, David and Frederick have already been sent to a “well-deserved rest”.

1. There are 6 separate lists of hurricane names. Special rule: each list is used only for 1 year, and is repeated every 7th. The most destructive and destructive names are removed from the list to prevent their recurrence.
2. The largest in terms of destruction was Katrina. Caused more than US$100 million in damage.

Conditions for the occurrence of cyclones

Such natural phenomena cannot just happen in the middle of a lake. To thrive, they need certain conditions:

• The depth of the reservoir is at least 60 m
• The water temperature in it is from 27°C
• The higher the temperature, the more destructive and powerful the hurricane

Video

How human curiosity and the desire to film it does not stop us from the mortal danger of a tsunami.

What is the difference between a tornado and a hurricane

Hurricanes can last for several days. And with a tornado, the elements rage from a couple of tens of minutes to several hours.

! Hurricanes are 1500-2000 times stronger and more permissive in strength and size than tornadoes.

If you make associations: a tornado is as wide as a hot dog, and a hurricane is as wide as a football field in a stadium.

1. Tornadoes are predominantly caused by hurricanes. Hurricane Andrew (1992) produced 62 tornadoes, and Hurricane Beulah (1967) produced a whopping 141. A tornado can start even a week after a hurricane.
2. There is an unusual consequence - the Fujiwara phenomenon. When two or more cyclonic vortices revolve around each other and a common core. This creates a more powerful and powerful tropical vortex.

Up to 10 tropical storms form annually. Of these, only 6 turn into a hurricane

1. A tornado has speed and far exceeds the strength of a hurricane. Like a sprinter: the distance is shorter and the speed is greater. A hurricane's speed exceeds 30m/sec.
2. The eye is the center of the cyclone. The air drops down there and the weather is very calm and clear. The “Eye” has a regular circular shape and a diameter of up to 370 km (maximum).
3. Around the “eye” there is a ring of thunderclouds. They are called a wall. It causes the most destructive consequences.

The same natural phenomenon such as a storm or tropical cyclone in different parts of the ocean has its own name:

1. Up to 10 tropical storms form annually. Of these, only 6 turn into a hurricane.
2. Five of them hit the shores of the United States.
3. An attempt was made to influence the strength and direction of the elements. A project called Stormfury was organized (1962-1983). Aircraft were sent to the center of the cyclone, which emitted silver iodides. It was assumed that they would cause the supercooled water in the storm to freeze, and the structure of the cyclone would be destroyed.

Small natural disasters were stopped in this way. But later it turned out that for the most part there is not such a large amount of supercooled water in the clouds and, by and large, this is a waste of money.

Based on the damage and destruction caused, Patricia was named the most powerful destructive hurricane on the planet.

Currently, this service is engaged in monitoring and forecasting the intensity of incipient cyclones.

The most powerful hurricane in the world

Based on the damage and destruction caused, Patricia was named the most powerful destructive hurricane on the planet. He attacked Mexico in October 2015. Periodically, the wind created gusts of up to 400 km/h.

What is more destructive: earthquake or hurricane?

If we compare the destructiveness and consequences of earthquakes and cyclones, then the following happens every year in the world:

• 500,000 vibrations of the earth's crust with victims of up to 100,000 people
• 85 typhoons, hurricanes and tornadoes with much less consequences

Scientists blame global warming, human factors and natural repeating cycles for the increasing number of such cases.

Only time will tell what awaits us.

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30 interesting facts about Singapore that can surprise everyone! Part 2

Every day we learn more and more sad news about how the powerful Hurricane Harvey, raging in the Gulf of Mexico, causes more destruction and claims an ever-increasing number of lives. Hurricanes, typhoons - all this is practically unknown to residents of the middle zone, and therefore we decided to tell you about what this natural disaster actually is.

What is a hurricane

The term "hurricane" has two main meanings. Firstly, a hurricane is a storm, that is, a very strong wind whose speed exceeds 30 m/s. Often such storms are accompanied by strong disturbances at sea or ocean. However, we are interested in the second, narrower and more familiar meaning, according to which a hurricane is a low-pressure weather system. It occurs over heated areas of open water of sufficient size and is accompanied by powerful thunderstorms, showers and storms. From space, a hurricane looks like a huge funnel of clouds: it receives energy from the fact that warm, moist air rises, after which the moisture condenses in the form of water vapor and falls as rain, while the warm air, which has become dry, falls down. Hurricanes are also called "warm-core cyclones" because the operating principle of polar and extratropical cyclones is completely different.

Storm winds during a typhoon cause the sea to crash huge waves onto the coastline

The word “hurricane” itself comes from the name of the Mayan god of the wind - Huracan. There is another popular name for a hurricane - “ tropical cyclone" But in Japan and the Far East hurricanes are called typhoons. They arise and maintain their strength only above the surface of large bodies of water, and if the wind blows a hurricane onto land, it will quickly exhaust itself. Therefore, it is the coastal areas that suffer the most from the elements, but heavy rains generated by hurricanes often cause extensive flooding even at a distance of 40 km from the coast. Despite the fact that tropical cyclones often cause enormous damage to infrastructure, they cannot be called absolute evil. Firstly, it is thanks to hurricanes that drought ends in some areas of the Earth and the vegetation landscape is restored. Secondly, tropical cyclones transfer large amounts of energy from equatorial latitudes towards temperate latitudes, which makes them an important component of global atmospheric circulation processes. This leads to a decrease in temperature on various parts of the planet's surface, so that it avoids overheating and maintains a stable temperate climate.

What does a hurricane consist of: the eye of the storm

Diagram of the structure of a hurricane: red arrows show flows of warm air, blue arrows show gradually cooling air

Eye of the Storm(or simply “eye”) is the central part of the cyclone, in which warm air falls down. As a rule, it retains a regular round shape, and its diameter can reach from 3 to 370 km, but on average the size of the eye is 30−60 km. An interesting “stadium effect” is associated with it: in large cyclones, the upper part of the eye is noticeably wider than the lower, which, when observed from the inside, actually resembles the shape of a stadium bleacher.

Large cyclones usually have a clear eye and a clear sky; in small ones it can be partially or completely covered with clouds, which is characterized by significant thunderstorm activity.

Wall of the eye

The eye wall of a storm can be seen either from inside the hurricane or in photographs of space satellites

In fact, the eye is an opening that forms a ring of dense cumulus thunderclouds. Here the clouds reach their greatest height, but the maximum wind speed is not achieved at the top of the wall, but at a low altitude above the surface of the water or land. Remember the videos from the Internet where strong winds lift small buildings off the ground and blow away cars? This is precisely the destructive power of a hurricane wall passing over a populated area.

Strong cyclones (category 3+) change the wall several times throughout their existence. At the same time, the old wall narrows to 10-25 km, and it is replaced by a new one of larger diameter. Changing the wall is a good sign: during each such procedure the cyclone weakens, but it is worth keeping in mind that after the final formation of the new wall it will quickly gain its previous strength.

Outer zone

The wide canvas of a hurricane consists of so-called rain bands - lines of dense thunderstorm clouds that slowly diverge from the center of the cyclone. The wall and outer zone is the area where moist air rises through circulation cells, but they are all smaller than the central one.

What happens when a hurricane makes landfall? An increase in surface friction causes a concentration of air flows and, as a result, rainfall.

However, the hurricane is not limited to these categories. Due to the centrifugal movement of air, it forms cloud cover even at very high altitudes. These clouds have little in common with the dense cumulus cover of the wall and outer zone: light and cirrus, they move quickly from the center of the cyclone and gradually disappear. They can become the first signal warning of the imminent arrival of a cyclone.

Hurricane Harvey

The aftermath of Hurricane Harvey: highways turned into pools of dirty water

So what makes it stand out among its peers? Harvey", currently turning Texas into a water-covered wasteland? For starters, this is the strongest hurricane in the Gulf of Mexico since the famous Katrina, which hit the United States in 2005. He was initially classified as category four on the Saffir-Simpson scale. This is the so-called huge hurricane": the wind speed on its territory reaches 50−70 m/s, and the flooded zone is located at an altitude of up to 3 meters above sea level, while the floods extend ten kilometers inland.

On the last day of summer, the US National Weather Service reported that Harvey had weakened and moved from a tropical storm to a tropical depression: wind speeds had dropped significantly, but heavy rainfall was still continuing. We can only hope that the cyclone will soon disappear altogether: at present, the federal authorities are finding it difficult to give even an approximate estimate of the damage that the disaster caused along its entire path.