Tropical hurricanes. Tropical cyclones, hurricanes, typhoons What is “CLIPER”

The first blow is full force. The house is falling apart. I looked at the barometer, which showed 674.5 mm, dropped it into the water, and was blown out into the sea by the wind.

I came to in a tree and saw that I was stuck in the branches of a palm tree 20 feet above the ground.

“You can easily imagine my surprise, chagrin... when I saw the terrible situation of the island of Barbados and the destructive power of the hurricane. The strongest buildings and entire blocks of houses, most of which were made of stone and were distinguished by their solidity, succumbed to the fury of the wind and were torn down to the ground. Entire forts on the fortress were destroyed, and many of the heavy guns were carried more than 100 feet from them. If I hadn't seen it myself, nothing would have made me believe it. More than six thousand people died, and all homes were completely destroyed." To this testimony of Admiral Rodney, who was at that time the commander of the English fleet and an eyewitness of the “Great Hurricane” in the West Indies in 1780, one can only add that the total number of human casualties then amounted to more than twenty thousand. thousand Dozens of ships with their entire crew sank, the islands of Barbados, St. Lucia, Dominica, St. Vincent, and Puerto Rico were completely devastated.

In some tropical regions of the globe, residents of islands and coastal areas sometimes suffer terrible disasters caused by small-diameter cyclones, in which wind speeds in some cases exceed 120 meters per second, and the amount of precipitation falling per day reaches 1000 - 12000 millimeters.

All cyclones originating in the tropics can be divided into four groups:

– tropical disturbance – area of ​​weak cyclonic circulation;

– tropical depression – a weak tropical cyclone with a pronounced surface circulation; the highest steady wind speed does not exceed 12.5 meters per second;

– tropical storm – a cyclone, the highest sustained wind speed of which reaches 33 meters per second;

– a tropical hurricane is a cyclone in which the wind speed exceeds 33 meters per second.

In Japan, tropical hurricanes are called “typhoons”, in the Philippines – “bagwiz”, in Australia – “willy-willy”. All these names translated into Russian mean “big wind” or “ strong wind».

There are several theories about the origin of tropical hurricanes.

According to the convective theory, hurricanes arise due to the development of intense convective vertical air currents over the hottest parts of the ocean, distant from the equator at such a distance at which the deflecting force of the Earth's rotation is capable of imparting vortex motion to air masses. The unstable thermal stratification of the atmosphere that often occurs in these areas contributes to the intense rise of air supersaturated with water vapor. At the moment of steam condensation, a huge amount of latent heat of vaporization is released, which turns into the kinetic energy of the cyclone.

In the central part of the cyclone, under the influence of centrifugal ejection of air with a small influx of air in the surface layer, the pressure quickly drops. Initially mild depression atmospheric pressure deepens, and after just a few days a powerful cyclone begins to move westward, increasingly increasing its depth and speed of movement. The strength of the wind in it also increases. The cyclone develops into a tropical hurricane.

And finally, the eastern wave theory explains the formation of hurricanes by the passage of a long (up to 2000 kilometers long) wave of atmospheric pressure. This wave, moving from east to west, loses its stability and turns into a whirlwind.

Average duration The existence of a tropical hurricane ranges from 6 to 9 days. The longest-lived hurricanes are those that originate near the coast of Africa and in the area of ​​the Cape Verde Islands, cross the Atlantic Ocean twice and go far to the north. Their duration is 3 or 4 weeks. Sometimes tropical hurricanes turn into ordinary cyclones, and then the duration of their existence is enormous.

Thus, the hurricane of 1900, which killed 6,000 people in Galveston (USA) on September 8, began on August 27 in the mid-Atlantic, crossed the Caribbean Sea, the Gulf of Mexico and went deep into the continent. In the Great Lakes region, it transformed into an ordinary hurricane, but, maintaining its strength, crossed North America, the Atlantic Ocean, Europe and went far into Siberia. The duration of this hurricane was 27 days.

At the surface of the earth, a hurricane usually represents an almost circular area of ​​storm and hurricane winds with a diameter of up to 500, and in some cases up to 1000 kilometers. The highest wind speeds, sometimes exceeding 80 meters per second, occur in the ring at a distance of 30 kilometers from the center of low pressure. However, in some cases, destructive winds affect a wider area. For the Pacific Ocean, the average size of the destruction zones accompanying a typhoon reaches 40–80 kilometers, with the total size of a hurricane up to 1500 kilometers.

An amazing feature of tropical vortices is a high funnel (up to 10 - 14 kilometers) with steep sides, rotating at enormous speed.

Here is how an observer from an airplane crossing a hurricane picturesquely talks about the central part of the typhoon: “We are in the wall of the typhoon, in the zone of maximum winds, in the zone of convergence - the convergence of air flows, where crumpled, oblique, compressed winds are madly rushing towards a giant funnel of depression and cannot overcome the mysterious border of the wall.

And suddenly, when it seems that the Boeing is captured by the last explosion of elemental madness, there is a sudden silence.

This is the eye

This is the area of ​​the lowest pressure and the highest temperature...

This is an abyss, an abyss in the atmosphere, where, as if at the call of a prophet, fantastic hordes of millions of cubic meters of air rush, consumed by impatience and dizziness, aggravated by the heat, howling and whirling, raising the ocean in waves and foam, like road dust, thrown back, colliding with others crowds seized by the same mystical madness of matter...

There is a wall stretching around, a fortress, which seems to have been erected to make us captives of this country full of magical charm...”

And here is an excerpt from P. A. Molan’s book “Typhoon Hunters” (1967):

“You should not think that the typhoon is clearly demarcated, that it looks like a millstone spinning and grinding the earth into powder, or like a rotating column. It has no distinct boundaries - it is a vaguely outlined mass twice as tall as Everest, with a crater in the center that anyone who has seen it at least once can never forget. This is a world of violent forces, a world of inevitable destruction, a world with energy equal to that of three atomic bombs per second."

Indeed, the energy of tropical hurricanes is enormous.

The destructive power of cyclones, typhoons and hurricanes lies primarily in the colossal speed of the wind, which affects the land and causes disturbances at sea. The destructive effect of cyclones is associated with the turbulent, vortex movement of air particles. Destruction during cyclones is also associated with low pressure in their center, the eye. Extremely abundant showers that cause floods.

Tropical cyclones occur in tropical latitudes. They are characterized by a clear concentration of energy in a small space, large pressure drops and high wind speeds. Every year over earth's surface A total of 70-80 tropical cyclones are formed, but only a small part of them reaches destructive power, and of these, in turn, only a part captures land.

According to definitions, wind speeds in tropical cyclones must exceed 34 m/s. However, most of them are characterized by speeds significantly higher than 50 m/s; speeds of more than 100 m/s (that is, more than 360 km/h) have been recorded.

Let's consider the structure of a tropical cyclone. The diameter of its inner part - the eye, where calm reigns and the sky is clear, most often fluctuates between 10 and 20 km. The eye is surrounded by a so-called wall where the winds reach their maximum speed. Not only vortex, but also upward movement of air takes place in the wall. Some of the air in the outlying zones of the cyclone is drawn in, while the other part is released.

Tropical cyclones form all the time. This happens near the equator, most often in the band between 5 and 10° north or south latitude.

Cyclones most often move at a speed of 30-50 km/h. In the Atlantic and Pacific oceans, they first move west, then turn north and northeast. Over land, their routes become irregular: they turn, go back and cross their route. Such cyclones are especially dangerous. They are called wandering. Cyclone Flora, which devastated the eastern part of Cuba in 1963, also belonged to this type. East Asian cyclones (typhoons) first move straight to the west, and near land they turn north. Bay of Bengal cyclones move in a northwesterly direction directly over land.

The energy of tropical cyclones is colossal, and it is difficult to accurately calculate it. It is believed that an average cyclone releases approximately the same amount of energy as 50,000 atomic bombs with a yield of 30 kilotons. Ocean and wet air are needed by the cyclone as energy suppliers. The vapor rises, the pressure at altitude drops, and the vapor condenses. This condensation is the main source of energy that supports the life of the cyclone.

Hurricanes These are winds of force 12 on the Beaufort scale, i.e. winds whose speed exceeds 32.6 m/s (117.3 km/h).

Hurricanes occur during the passage of deep cyclones and represent the movement of air masses (wind) at enormous speed. During a hurricane, the air speed exceeds 32.7 m/s (more than 118 km/h). Sweeping over the earth's surface, a hurricane breaks and uproots trees, tears off roofs and destroys houses, power and communication lines, buildings and structures, and disables various equipment. As a result of a short circuit in electrical networks, fires occur, the supply of electricity is disrupted, the operation of facilities stops, and other problems may occur. harmful consequences. People may find themselves under the rubble of destroyed buildings and structures. Debris from destroyed buildings and structures and other objects flying at high speed can cause serious injuries to people.

Having reached its highest stage, a hurricane goes through 4 stages in its development: tropical cyclone, pressure depression, storm, intense hurricane.

Hurricanes typically move at 15 km per hour along a westerly path and often gain speed, usually veering toward north pole to the line 20-30 degrees northern latitude. But they often develop according to a more complex and unpredictable pattern. In any case, hurricanes can cause enormous destruction and staggering loss of life.

Modern methods Weather forecasts make it possible to warn the population of a city or an entire coastal region several hours and even days in advance about an approaching hurricane (storm), and the civil defense service can provide the necessary information about the possible situation and actions in the current conditions.

When spreading over the sea, a hurricane causes huge waves 10-12 m high or more, damaging or even leading to the death of ships.

After the hurricane, NASF, together with the entire working population of the facility, carries out rescue and emergency restoration work; rescue people from littered protective and other structures and provide them with assistance, restore damaged buildings, power and communication lines, gas and water pipelines, repair equipment, and carry out other emergency restoration work.

Tornadoes.

A tornado is one of the cruel, destructive phenomena of nature. According to V.V. Kushina, tornado - This is not wind, but a “trunk” of rain twisted into a thin-walled tube, which rotates around an axis at a speed of 300-500 km/h. Due to centrifugal forces, a vacuum is created inside the pipe and the pressure drops to 0.3 atm. If the wall of the “trunk” of the funnel breaks, encountering an obstacle, then the outside air. Pressure drop 0.5 atm. accelerates the secondary air flow to speeds of 330 m/s (1200 km/h) or more, i.e. up to supersonic speeds. Tornadoes are formed when the atmosphere is in an unstable state, when the air in the upper layers is very cold, and in the lower layers it is warm. Intense air exchange occurs, accompanied by the formation of a vortex of enormous force.

Such vortices arise in powerful thunderclouds and are often accompanied by thunderstorms, rain, and hail. Obviously, it cannot be said that tornadoes occur in every thundercloud. As a rule, this occurs on the edge of fronts - in the transition zone between warm and cold air masses. It is not yet possible to predict tornadoes, and therefore their appearance is unexpected.

A tornado does not live long, since pretty soon the cold and warm air masses are mixed, and thus the cause that supports it disappears. However, even over a short period of its life, a tornado can cause enormous destruction.

Until now, the tornado is in no hurry to reveal its other secrets. So, there are no answers to many questions. What is a tornado funnel? What gives its walls a strong rotation and huge destructive force? Why is a tornado stable?

Investigating a tornado is not only difficult, but also dangerous - with direct contact, it destroys not only the measuring equipment, but also the observer.

Comparing descriptions of tornadoes of the past and present centuries in Russia and other countries, one can see that they develop and live according to the same laws, but these laws are not fully understood and the behavior of the tornado seems unpredictable.

During the passage of tornadoes, naturally everyone hides and runs, and people have no time for observations, much less measuring the parameters of tornadoes. That little bit about internal structure The funnel that we managed to find out is due to the fact that the tornado, taking off from the ground, passed over the heads of people, and then it was possible to see that the tornado was a huge hollow cylinder, brightly illuminated inside by the brilliance of lightning. A deafening roar and buzzing sound comes from inside. It is believed that the wind speed in the walls of a tornado reaches sound speed.

A tornado can suck in and lift up a large portion of snow, sand, etc. As soon as the speed of snowflakes or grains of sand reaches a critical value, they will be thrown out through the wall and can form a kind of case or cover around the tornado. Characteristic feature This case-cover is that the distance from it to the wall of the tornado along the entire height is approximately the same.

Meteorological natural disasters are very dangerous, as they entail huge loss of life, clear example Moreover, Hurricane Katrina in the USA is associated with the destruction of buildings and structures, causing great damage to humanity, which, of course, is a problem on a global scale.

Archived article from No. 6 (42) for 2005.

Tropical cyclones are one of the most amazing and, at the same time, formidable and destructive natural phenomena on Earth, rampaging over the tropical waters of all oceans, with the exception of the south Atlantic and southeast Pacific.

On average, about 80 tropical cyclones are observed on our planet per year.

Intense tropical cyclones in each region have their own name. In the Atlantic and Northeast Pacific they are called hurricanes; in the northwest Pacific Ocean - typhoons; in the Arabian Sea and Bay of Bengal - by cyclones; in the southern part Indian Ocean– orcans; off the coast of Australia - willy-willy; in Oceania - wheelie-wow; in the Philippines - Baguio.

Tropical cyclones are huge vortices, reaching a diameter of 1000-1500 km and extending throughout the entire thickness of the troposphere. Distinctive feature tropical cyclones - a significant drop in pressure over short distances, which leads to the formation of hurricane winds. The pressure in the center of developed cyclones is about 950-960 hPa (the minimum recorded is 855 hPa).

Tropical cyclones arise over warm ocean waters in the tropics of both hemispheres in the latitude zone 5-20°. They are a formidable product of the interaction between the ocean and the atmosphere.

Most tropical cyclones form in the intertropical convergence zone - the zone of convergence of the trade winds of the two hemispheres, or trade winds, and the equatorial westerlies. Such a convergence zone is characterized by the presence of disturbances of varying intensity - some of them reach the stage of tropical depressions, some of which, when favorable conditions, developing into a tropical storm and hurricane. What contributes to the formation and further intensification of a tropical cyclone? First of all, this is the presence of an initial disturbance and a slight horizontal wind shear between the lower and upper troposphere. To create the “twisting” effect, a sufficient value of the Coriolis force is necessary, due to the rotation of the Earth around its axis - tropical cyclones do not form near the equator, where the horizontal component of this force is zero. One of the conditions for the formation of tropical cyclones is the presence of moist, unstable air and the development of convection.

Finally, there is the existence of an energy source - the thermal potential of the ocean. Simply put, tropical cyclones form over the ocean if its surface temperature exceeds 26°C. The ocean supplies much of the heat needed to maintain the low pressure at the center of the cyclone. As water temperature rises, evaporation increases and the flow of so-called latent heat increases, which forms a warm core in the middle troposphere, causing a sharp decrease in pressure in the center of a tropical cyclone. A tropical cyclone can be thought of as a heat engine, the operation of which is connected to the ocean as a source of energy and as a trigger mechanism - the initial vortex is formed over a superheated area of ​​​​the ocean. In addition, the thermal state of the ocean also affects the trajectory of tropical cyclones. But at the same time, the evolution of tropical cyclones is also determined by various atmospheric processes. We are dealing with a complex set of interactions between the ocean and the atmosphere.

Mature tropical cyclone – powerful atmospheric vortex, which is characterized by large pressure gradients (differences) and, consequently, hurricane winds - up to 90 m/s, with the belt of maximum winds located between 20 and 50 km from the center. In tropical cyclones, intense cloudiness develops, and the amount of precipitation can reach 2500 mm per day. In well-developed cyclones, a phenomenal phenomenon is observed - the eye of the storm - an area where the sky clears, the wind weakens, sometimes to the point of calm, and at its border the precipitation suddenly stops. The eye is surrounded by a wall of powerful clouds. Satellite images discovered the existence of “hot towers” ​​- high-altitude zones of rain clouds that are located above the “walls” of this very “eye” much higher than the main part of the hurricane. The "towers" extend all the way to the "ceiling" - upper layers troposphere. Experts believe that “hot towers” ​​play a key role in the process of increasing the power of a hurricane. By the way, such “towers” ​​were also discovered in Hurricane Katrina. The appearance of the eye of the storm is associated with an increase in centrifugal force as it approaches the center of the cyclone. The average diameter of the “eye” is 20-25 km; in destructive hurricanes and typhoons it is 60-70 km. There are also two-eyed tropical cyclones.

The energy of a tropical cyclone is very high; According to experts, the average tropical cyclone produces an amount of energy equal to several thousand atomic bombs.

In three weeks, a hurricane generates energy comparable to what our Bratsk hydroelectric power station would have generated in 26 thousand years. Humanity is not yet able to either use this energy or receive it in such quantities from any other sources.

The resulting tropical cyclone first moves from east to west, gradually deviating to higher latitudes: in the northern hemisphere - to the northwest. But if the cyclone reaches 20-30° latitude above the ocean, it begins to go around the subtropical anticyclone and its direction changes to the northeast. This point on the trajectory is called the turning point. The trajectories of cyclones are mostly curvilinear, sometimes even “loops” appear. The average speed of tropical cyclones within the tropics is only 10-20 km/h. Coming onto land or into mid-latitudes, a tropical cyclone fades or turns into an intense cyclone of temperate latitudes. In the summer-autumn period, Russian Primorye is often exposed to such cyclones - former typhoons that bring abnormal precipitation and hurricane winds. Thus, in 1973, a typhoon that hit Primorye brought more than half of the annual precipitation to Vladivostok. The author of the article experienced all the “delights” of the raging elements when in August 1979 Typhoon Irving hit the Far East, flooding the Primorsky and Khabarovsk Territories.

In hydrometeorological practice, depending on the wind speed, tropical disturbances are divided into tropical depression, tropical storm, severe tropical storm, tropical cyclone, typhoon, hurricane. In turn, the latter are divided into five categories (“hurricane” Saffir-Simson scale) depending on wind speed. The fifth category includes hurricanes with speeds exceeding 70 m/s.

Tropical cyclones that have become tropical hurricanes, get their names. This tradition dates back to World War II, when air force meteorologists naval forces The United States monitored typhoons and, to avoid confusion, named typhoons after their wives or girlfriends. After the war, the US National Weather Service compiled alphabetical list female names to facilitate communication and avoid difficulties when several cyclones develop in the region. When, in 1979, the true essence and strong half humanity, the World Meteorological Organization (WMO), together with the US National Weather Service, included in the list and male names. Justice has prevailed. (Not all evil is from a woman!) These lists are used constantly and are compiled in advance for each year and each region. However, if a tropical cyclone is particularly destructive, the name assigned to it is removed from the list and replaced by another. So we can say quite definitely that we will never hear about a hurricane called Katrina again.

The destructive effect of tropical cyclones is due to hurricane-force winds, deadly streams of water that hit the coast with the arrival of a hurricane - up to 20 million tons of water per day. For example, in January 1966, tropical cyclone Denis swept over Reunion Island in the Indian Ocean, bringing an incredible amount of rain - 182 centimeters per day. Added to the rainfall is a “storm surge” - a rise in sea level, reaching 10 m in extreme cases. Floods associated with storm surges are the most destructive consequences of hurricanes. In 1970, Cyclone Ada in the Indian Ocean inundated the low-lying coast of Bangladesh with surge waves. More than 300 thousand people died then. Hurricane Hugo in 1989 dumped a wall of water 20 feet high on South Carolina. Such a blow can destroy buildings, roads, and wash away banks.

In the northern hemisphere, the hurricane season lasts, on average, from May to November. The longest period of development of tropical cyclogenesis is observed in the western Pacific Ocean. According to the Hydrometeorological Center of Russia, which contains a data bank on tropical cyclones throughout to the globe On average, 26 tropical cyclones form in the western Pacific Ocean. In the Atlantic, the peak of hurricanes occurs in August-September and there are about 9-10 cyclones per year. Research by scientists has shown that tropical cyclone activity has increased in the Atlantic in recent decades. Thus, from 1970 to 1979 their number was 81, from 1980 to 1989 – 96, from 1990 to 1999 – 105; Moreover, in 1995, 19 tropical cyclones were recorded (the record still remains for 1933, when 21 cyclones formed in the Atlantic). According to the forecasts of American scientists, this trend will continue in the first decades of the 21st century, and the current year 2005 may break all records. This is due, first of all, to an increase in ocean surface temperature. Satellite data showed that in 2005 the water surface temperature in the Atlantic Basin increased by an average of 2-4°C compared to previous years.

Until recently, the record holder among Atlantic cyclones was Hurricane Andrew, which swept over the states of Florida and Louisiana at the end of August 1992 and caused damage in the amount of $25 billion. The minimum pressure in its center dropped to 923 hPa, and the wind speed reached 76 m/s.

However, Katrina, apparently, turned out to be a record holder in its parameters: the minimum pressure in its center was 902 hPa, and the wind speed exceeded 75 m/s (gusts up to 90 m/s). Katrina originated on August 23, 2005, east of the Bahamas and, after passing through southern Florida and intensifying in the Gulf of Mexico, where water temperatures exceeded 31°C, struck New Orleans on August 29, 2005, destroying levees and completely flooding the city. The death toll exceeded a thousand people, and economic damage amounted to tens of billions of dollars. It was the most destructive hurricane ever to hit the coast. North America.

Following Katrina, Rita rushed to the US coast, becoming the seventeenth tropical storm of the 2005 hurricane season.

Fortunately, she weakened before causing any colossal harm. Both Katrina and Rita originated north of normal latitudes where Atlantic tropical cyclones swirl. But the most unusual thing for the Atlantic was the twentieth hurricane named Vince. He managed to spin around the Azores Islands, which is significantly north (30-35 parallel) of the usual area of ​​their formation. True, it failed to achieve great intensity and, having reached the first category, “Vince” quickly weakened to a tropical storm.

Tropical cyclones significantly redistribute energy in the atmosphere and therefore, despite their “compact” size, influence atmospheric processes far beyond their “habitat”. For example, climatologists have noticed an interesting fact about the relationship between the frequency of hurricanes in the Atlantic and good weather in Europe. As a rule, with increased activity of tropical cyclogenesis, large, inactive cyclones form over Scandinavia. Along their periphery, winds spread over most of Western Europe southern directions, which provide stable warm weather. Eastern Europe At the same time, it is at the mercy of an anticyclone, which causes good weather. So our long “Indian summer” of 2005 is partly due to the “raging” Atlantic.

There is no need to talk about the importance of studying tropical cyclones and forecasting their evolution. Direct measurements in a cyclone are practically impossible, although many useful information was obtained during aircraft sounding and special expeditionary observations. Modern methods for studying and forecasting tropical cyclones are based on numerical modeling and the use of satellite information and laboratory experiments. Methods have been developed to predict the occurrence, evolution and direction of movement of these cyclones based on numerical methods and satellite data. Although it is not yet possible to accurately calculate the origin of a tropical cyclone, it is quite possible to determine the most likely area of ​​its origin. Over the past 30 years, significant advances have been made in predicting cyclone trajectories.

The enormous damage caused by tropical cyclones raises the challenge of not only predicting their development and movement, but also of possible influence on them in order to reduce their intensity and change the trajectory of movement. A wide variety of projects were proposed: dispersing clouds with dry ice or silver iodide, cooling the ocean with icebergs, covering water with a special oil film, irradiating the epicenter of a hurricane with microwaves from space or detonating it with hydrogen bombs. It should be noted that all of them are quite expensive and may turn out to be absolutely meaningless if there is no accurate forecast of the location of origin, size and intensity of the cyclone. In addition, it is impossible to calculate the consequences of such impacts, which may be no less destructive than the tropical cyclone itself. So for now we can only hope for improved methods for forecasting tropical cyclones and adequately respond to warnings from specialists. And now, thanks to the improvement of warning systems and methods of saving people, the number of human casualties has begun to gradually decline.

Text: Olga Razorenova (senior researcher, Institute of Oceanology RAS)
Photo: Levan Mtchedlishvili

The destructive activity of typhoons and hurricanes is carried out due to the combined action of the colossal force of the wind, the enormous amount of precipitation, the storm's rise in sea level and the resulting giant waves.

The Beaufort scale for a unified assessment of the state of the sea from one (calm sea) to 12 points (hurricane - a sea white with foam and waves reaching a height of 15 m) turned out to be unsuitable for characterizing wind speed during typhoons and hurricanes. To these 12 points, 5 more were added; the last 17 points corresponds to a wind speed of 460 km/h.

Modern instruments are not capable of recording wind speeds of more than 300 km/h. The record speed is approximately 400 km/h, which does not mean an instant gust, but a wind blowing for 5 minutes. Individual gusts have a speed of 20 - 30% more.

In tropical cyclones, wind speeds often reach 300 - 400 km/h. Such speeds cannot be measured. They are judged by the destruction that cyclones leave behind. Often during the passage of these hurricanes fall heavy rains and hail. Waterfalls falling from the sky and accompanied by the roar of the wind are terrifying. There are known cases when, in areas of future typhoons, the surfaces of bays were covered dead fish, who died from excess fresh water.

Tropical cyclones along their path cause enormous material damage and claim many human lives.

Residents of the Philippine Islands, Indochina and Japan have known the word “typhoon” since time immemorial. Bay of Bengal typhoons have claimed many victims. They contribute to storm floods that inundate low-lying, densely populated coastlines.

There are cases when one typhoon claimed thousands of lives, for example, Typhoon Vera in September 1959 killed 5,500 people. This number will increase significantly if you take into account the people who died later from hunger and disease.

Damage caused to material assets can be divided into direct and indirect. Direct is damage that occurs directly during a storm (destruction of buildings, fires, loss of crops, etc.). Indirect damage is damage that occurs long after typhoons and hurricanes pass over islands and continents. For example, the absence of a harvest for several years in those fields from which the surface layer of soil was carried away, a reduction in production in destroyed plants and factories. The amount of indirect damage caused by a tropical cyclone can be several times greater than the amount of direct damage. Long-term statistics of observation of tropical cyclones have made it possible to identify some patterns linking the amount of damage caused to the physical characteristics of tropical cyclones. This allows you to get a rough idea of ​​the scale of the impending disaster.

The biological significance of cyclones lies in their ability to transport plant seeds and sometimes quite large animals over vast distances. Apparently, it was these winds that contributed to the settlement of many volcanic and coral islands that arose in the vastness of the oceans, and the migration of plants and animals. The hurricane of 1865 brought pelicans to Guadeloupe, previously unknown there.

The famous Great Hurricane in October 1780 destroyed the city of Savanna-la-Mar (Georgia, USA). According to an eyewitness, the residents were petrified with amazement when they saw the approach of an unprecedented wave; sweeping away all obstacles in one gigantic squall, it flooded the city and demolished everything and everyone. Seven days later the storm reached its maximum strength. It completely devastated the island of St. Lucia, where 6,000 people died under the ruins, and sank the English fleet anchored off the island. The sea here rose so high that it flooded the fleet and, carrying a ship on the crest of one of its gigantic waves, threw it onto the naval hospital, destroying the building with the weight of the ship. The hurricane then headed towards the island of Martinique, where 40 French transport ships carrying 4,000 soldiers were sunk. The islands of Dominica, St. Eustatius, St. Vincent, and Puerto Rico located to the north were also devastated, and a large number of ships caught in the path of the cyclone were sunk.

On the night of November 13, 1970, an incredible typhoon hit the coastal areas of East Pakistan (since 1971). People's Republic Bangladesh). A powerful wave up to 8 m high, raised by the wind, passed over a chain of densely populated islands. It was a colossal wall of water, boiling and seething, a huge shaft of water that was thrown up by the ocean. Sweeping away everything in its path, it hit the coast and, together with hurricane winds, brought catastrophic destruction. For several hours these islands and part of the mainland coast were under water. The consequences of the typhoon are catastrophic: bridges are torn down, highways and railways are destroyed, entire villages are completely destroyed along with their inhabitants. According to newspaper reports, a total of more than 10 million people were affected by the typhoon. The death toll exceeded half a million, and according to some sources, about a million people. One of the most severe natural disasters in the history of mankind occurred.

A hurricane of extraordinary force hit 11 states in North America in 1974. Sowing death and destruction, the hurricane and the accompanying tornadoes in 8 hours left in its path, according to published data, 350 killed, thousands of wounded and missing. Hundreds of homes and stores, schools, hospitals and churches were destroyed in the states of Illinois, Indiana, Ohio, Kentucky, West Virginia, Virginia, Tennessee, North Carolina, Alabama and Georgia. Material damage, according to incomplete data, is estimated at $1 billion. Among the hardest hit by the hurricane is the city of Zinia in Ohio. According to eyewitnesses, the hurricane struck suddenly at about 5 o'clock. evening, rumbled like a passenger train rushing at great speed. In a city with a population of 25 thousand, over 70% of buildings were completely or partially destroyed, including the state university. The city of Brandenberg ceased to exist. In Alabama, the cities of Jasper and Guin were wiped off the map.

On the eve of 1975, tropical cyclone Tracy almost completely destroyed the capital of the northern territory of Australia, Darwin, a city with a population of 44 thousand people. The wind force reached a speed of 260 km/h. The hurricane tore roofs off houses like balls and tossed tourist buses through the streets. Numerous cottages were collapsing under the pressure of the wind, like houses of cards. But administrative buildings and high-rise hotels were hardly more stable. Darwin's downtown has been reduced to mountains of rubble and debris. A large naval base located near the city was destroyed. Several ships sank.

In 1980, during August and September 1980 alone, four cases of tropical cyclone development were noted in the northern hemisphere and one case in the southern hemisphere, of which two were hurricanes in the Caribbean Sea and three were typhoons in the Pacific Ocean.

Hurricane Alley occurred in early August off the coast of Haiti and Jamaica. The wind speed there reached 70 m/s. The second hurricane, Hermine, was observed on the 20th of September off the northern coast of Honduras, as well as off the coast of Mexico and Guatemala. The wind speed there reached 30 m/s.

Typhoon Orchid originated in the western Pacific Ocean and on September 11-12 swept over the Japanese islands and South Korea, causing significant destruction and causing floods there. The influence of this typhoon became noticeable a day later in the Khabarovsk and Primorsky territories and on Sakhalin. Observed heavy rains and wind, the wind speed in some places reached hurricane speed (33 m/s). About a month later, in mid-October, another typhoon came to the Japanese islands of Kyushu and Shikoku from the south, temporarily disrupting not only air but also railway communications.

At the beginning of the third ten days of September, Typhoon Kay arose in the southeastern part of the Pacific Ocean, in the center of which the wind speed reached 30-40 m/s.

There were tropical cyclones in subsequent years, both in the northern and southern hemispheres. In particular, tropical cyclones Eilena, which struck the Comoros Islands in the Indian Ocean on January 10, 1983, and Andry, which caused great destruction on the northwestern coast of the island of Madagascar in the Indian Ocean, were very destructive.

1985 was also a good year for tropical cyclones: in the South China Sea during the summer and autumn of this year, seven tropical cyclones - typhoons - occurred, causing catastrophic floods and human casualties in the coastal areas of Vietnam and China.

One of the typhoons, Lee, penetrated far to the north onto the Korean Peninsula and, turning into an ordinary cyclone, brought with it heavy rains to the territory of Soviet Primorye in mid-August.

Another typhoon on September 10-12 destroyed a third of the fruit harvest and caused damage to about 90% of the cultivated area in Japanese island Honshu.

At the end of October, Typhoon Saling killed more than 60 residents of the island of Luzon in the Philippines and caused more than 700 million pesos in damage to the island's farms. Almost simultaneously, in the other hemisphere, in the Gulf of Mexico, another tropical cyclone arose - Hurricane Juan, which severely affected residents of several coastal US states, and a month later - Hurricane Kate, which caused floods and significant destruction in northern Cuba and the United States. Hurricane Kate's intensity and extent of damage caused. Cuba and the coast of the Florida peninsula turned out to be one of the most ferocious in the last 50 years; gusts of wind and ocean waves rushing onto the shore destroyed many thousands of houses, more than a million people had to be evacuated from disaster zones, and there were casualties.

Tropical Cyclone Jeanne (September 2004) - Caribbean Sea, Haiti. The death toll from rain, flooding and landslides in Haiti caused by Hurricane Jeanne could reach 2,000, the Associated Press reported. As of September 23, almost 1,100 victims are already known, and another 1,250 people are listed as missing. The most a large number of victims - in the city of Gonaives in the northern part of the island. According to authorities, 1,013 people died here. Representatives of the Red Cross fear the spread of epidemics through water in which the bodies of drowned people remained for several days. The water level in some places exceeds four meters, and as it recedes, more and more victims are discovered. The President of Haiti called what was happening humanitarian catastrophe and asked the international community for help. In May 2004, the island already suffered one of the worst floods in history, which killed about 2.5 thousand people.

Hurricane Katrina is one of the most destructive hurricanes in US history. As a result natural disaster 1,836 residents died, economic damage amounted to $81.2 billion. physical characteristics. Before it reached the US coast, it was classified as a level 5 hurricane on the Saffir-Simpson Hurricane Scale. Fortunately, about 12 hours before hitting the coast, the hurricane weakened to Category 4. The wind speed during the hurricane reached up to 280 km/h (according to other reports, 62 m/s (? 223 km/h). On August 27, 2005, it passed over the coast of Florida near Miami and turned towards the Gulf of Mexico. On August 29, 2005 it reached the south east coast of the United States in the region of Louisiana and Mississippi. Due to their location below sea level, many cities of the southeastern coast of the United States were flooded. In New Orleans, this happened to 80% of the city, many buildings collapsed. Economic damage amounted to $ 125 billion. ( estimate, 2007). About 800 thousand people were left without electricity and telephone communications. The officially confirmed number of victims was 1,407 people, according to later data 1,600, of which more than 720 were in New Orleans; in addition, as of December 2005, 47 people were missing missing More than a quarter of the population of New Orleans (150 thousand people) have still not returned to the city (August 2006).

On March 14, 2007, Madagascar was again hit by disaster. Another tropical cyclone, Indlala, reached category 3 in strength. The wind speed in this cyclone reached 115 knots with gusts up to 140 knots. Reportedly news agencies Over the past few days, this cyclone has claimed the lives of 36 people, 53 thousand 750 people were left homeless. Since December 2006, Cyclone Indlala was the fourth to hit Madagascar. On March 19, 2007, he left the island. While the north of the island experiences devastating floods due to powerful cyclones, its South part experiencing drought and famine. The cyclone season in the southern Indian Ocean usually lasts from November to March. But the 2006/07 season. differs from the previous ones by greater activity.

On October 7, 2008, Mexico was literally in the grip of tropical cyclones. Tropical Storm Marco has formed in the Gulf of Mexico. Wind gusts reached 27 m/s. Storm "Marco" came close to the coast. Brought torrential rains. On the other side of Mexico, over the Pacific Ocean, there is another cyclone - Hurricane Norbert.

Tropical cyclones

Tropical cyclones carry enormous reserves of energy and have great destructive power. Kinetic energy an average-sized cyclone is comparable to the explosion energy of several powerful hydrogen bombs and accounts for about 10% of the total kinetic energy of the northern hemisphere.

Despite the fact that most countries have a warning system for tropical cyclones, the passage of each of them is accompanied by undesirable consequences for humans. Human casualties and enormous material damage are associated with hurricane winds, floods caused by heavy rainfall, as well as storm surges of water (surge - the rise of water along the coast when a cyclone moves onto land, can reach 8 m or more).

One of the most destructive hurricanes - "MITCH" in October 1998, killed 10,000 people in Honduras and Nicaragua and left 2 million people homeless. These countries experienced the worst floods in the last 200 years. The total economic damage from the hurricane exceeded $5 billion.

Areas of origin of tropical cyclones

Tropical cyclones can occur at any time of year in tropical parts of all oceans except the southeastern Pacific and South Atlantic. Most often they form in the northern part tropical zone Pacific Ocean: on average, about 30 cyclones are tracked here per year. The main season for the development of tropical cyclones is August - September; in winter and spring their frequency is very insignificant.

Most often (in 87% of cases) tropical cyclones occur between latitudes 5° and 20°. At higher latitudes they occur in only 13% of cases. Cyclones have never been observed to occur north of 35° north latitude and south of 22° south latitude. Tropical cyclones that have reached significant intensity have their own name in each region. In the eastern part of the Pacific Ocean and in the Atlantic they are called hurricanes (from the Spanish word “huracan” or English “haricane”), in the countries of the Hindustan Peninsula - cyclones or storms, in Far East- typhoons (from the Chinese word “tai”, which means strong wind). There are also less common local names: "willy-willy" - in Australia, "willy-wow" - in Oceania and "baguio" - in the Philippines.

Pacific typhoons and Atlantic hurricanes are named according to established lists. For typhoons four lists of names are used, one is set for hurricanes. Each typhoon or hurricane formed in a given calendar year, in addition to the name, a serial number is assigned, a two-digit digit of the year: for example, 0115, which means the fifteenth typhoon number in 2001.

Causes and evolution of tropical cyclones

Tropical cyclones form where observed heat water surface(above 26°), and the water-air temperature difference is more than 2°. This leads to increased evaporation and an increase in moisture reserves in the air, which to a certain extent determines the accumulation of thermal energy in the atmosphere and contributes to the vertical rise of air. The emerging powerful draft carries away more and more volumes of air, heated and moistened above the water surface. The rotation of the Earth gives the rising air a vortex motion, and the vortex becomes like a giant top, the energy of which is enormous.

The central part of the funnel is called " eye of the storm" This is a phenomenal phenomenon that amazes with the peculiarities of its “behavior”. When the eye of the storm is well defined, precipitation suddenly stops at its boundary, the sky clears, and the wind weakens significantly, sometimes to calm. The shape of the eye of a storm can be very different, it is constantly changing. Sometimes there is even a double eye. The average diameter of the eye of a storm in well-developed cyclones is 10 - 25 km, and in destructive ones it is 60 - 70 km.

Tropical cyclones are called depending on their intensity:

1. Tropical disturbance - wind speeds are low (less than 17 m/s).

2. Tropical depression - wind speed reaches 17 - 20 m/s.

3. Tropical storm - wind speed up to 38 m/s.

4. Typhoon (hurricane) - wind speed exceeds 39 m/s.

IN life cycle There are four stages of a tropical cyclone.

1. Formation stage. It begins with the appearance of the first closed isobar (isobar is a line of equal pressure). The pressure in the center of the cyclone drops to 990 hPa. Only about 10% of tropical depressions develop further.

2. Young cyclone stage or development stage. The cyclone begins to quickly deepen, i.e. there is an intense drop in pressure. Hurricane force winds form a ring with a radius of 40 - 50 km around the center.

3. Maturity stage. The drop in pressure in the center of the cyclone and the increase in wind speed gradually stop. The area of ​​stormy winds and intense rainfall increases in size. The diameter of tropical cyclones in the development and mature stages can range from 60 - 70 km to 1000 km.

4. Attenuation stage. The beginning of the filling of the pressure growth cyclone at its center). Attenuation occurs when a tropical cyclone moves into an area of ​​greater low temperatures surface of the water or when moving onto land. This is due to a decrease in the influx of energy (heat and moisture) from the ocean surface, and when reaching land also with an increase in friction with the underlying surface.

After leaving in temperate latitudes a tropical cyclone can lose its specific properties and turn into an ordinary cyclone of extratropical latitudes. It also happens that tropical cyclones, remaining in the tropics, reach the mainland. Here they quickly fill up, but at the same time manage to cause a lot of destruction.

Typhoons

Typhoons are among the most powerful and destructive tropical cyclones. Annual losses from typhoons cause significant damage to the economies of several Asian countries. Most economically underdeveloped countries have great difficulty in repairing the damage caused by typhoons.

Of the 25-30 typhoons that appear over the western part of the Pacific Ocean every year, from 1 to 4 enter the Sea of ​​Japan and the Primorsky Territory in different years. All of them occur over the ocean northeast of the Philippines. Average duration of a typhoon is 11 days, and the maximum is 18 days. Minimum pressure, observed in such tropical cyclones, varies widely: from 885 to 980 hPa, but when typhoons enter our territory, the pressure in their centers rises to 960-1005 hPa. Maximum daily precipitation amounts reach 400 mm, and wind speed - 20 - 35 m/s.