Abnormal air temperatures, heat and frost are a type of danger. The impact of extreme temperatures on the human body. What is the temperature in space

home Most cold and heat receptors located in the upper layers of the skin, they are directly exposed to the environment or objects. If the air temperature drops to 20-25 degrees, cold receptors are stimulated to the maximum. When the temperature rises to 40 degrees, heat receptors are maximally activated. And in brain and spinal cord

There are very sensitive receptors that monitor the temperature inside the body.

Could something else be affecting skin receptors? It could be some food ingredients

. For example, chili peppers activate heat receptors. Its pungency is perceived by the receptors as heat. In contrast, menthol activates cold receptors, which is why peppermint oil has a refreshing effect.

What temperature is comfortable for a person? It depends on how much well dressed man , and how much is it moves

. For a lightly dressed person, when sitting, a pleasant temperature of 29-32 degrees Celsius; when walking it is 26 degrees; when climbing a slope - 22 degrees. For a person wearing warm clothes, these values ​​​​fall: 21 degrees is ideal for long sitting; for walking - 13 degrees and for climbing - 4 degrees.

When do people start feeling cold? There are several reasons

: firstly, of course, when the ambient temperature drops; secondly, in response to rising body temperature during a cold; thirdly, if centralization of blood circulation occurs, for example, in response to fear, it causes a feeling of cold; fourthly, upon contact with a cold object.

What is centralization of blood circulation? This is a defensive reaction body. Under all circumstances, vital organs such as the heart, lungs and brain are well supplied with blood. Thus, the body restricts blood flow to the periphery. Legs and arms can freeze , while the body remains warm. When a feeling of fear arises, intelligent centralization directs more blood to the main organs, which causes feeling cold . A similar process occurs with wounds with blood loss. Blood drains from the surface of the skin, the skin turns pale as the central vital organs are protected. But the blood is distributed in such a way that the body temperature does not drop.

Is it possible to train cold tolerance?

With the help of exercises you can train the vascular system , which regulates blood circulation. Good for this purpose contrast baths , hot and cold showers or saunas. The better the regulation of blood flow, the better the skin perceives temperature changes. In addition, when low temperatures ah brown adipose tissue is activated. She has a special ability generate heat . But adults have very little of it. She plays with babies important role, as they freeze faster. Unlike white fat, this tissue does not contribute to obesity.

What help can be provided for hypothermia?

Man with hypothermia of the body needs to special medical care : Simply warming it up with coolants can become life-threatening because it will lead to cardiac arrest. Heat should be supplied internally in the form of soups or hot drinks. You can also wrap it in something warm to minimize heat loss. If a person is unconscious, you can only urgently consult a doctor.

Can alcohol help in the cold?

Attention, alcohol can be dangerous for two reasons: firstly, it expands blood vessels, causing the body to cool down more easily. Secondly, alcohol contributes inadequate assessments e cold. This is how many alcoholics freeze in winter on park benches.

It is known that the constancy of the temperature of the human body is the basis of its existence. Extremely low (as well as extremely high) air temperatures are a relative concept. They are typical for certain territories and represent significant deviations from the norm - the usual average temperatures of a given area. In winter, the air temperature in the area can often drop below 10–15°C relative to the norm at which the body is in physiological comfort. Physiological comfort human body depends on the climate (air temperature, humidity, wind speed). The average value of the comfort zone is 21–24°С, lower limit: –18°С, upper limit: + 27°С.

Extreme temperatures air are established during a winter anticyclone - areas high blood pressure air with maximum pressure in the center. In the subtropics, extreme air temperatures are also possible due to the invasion of cold air masses from higher latitudes.

The coldest continent is Antarctica. Russia also holds the world record for seasonal temperature fluctuations. In 1933, in Oymyakon (Sokha Republic), one of the so-called poles of cold, the lowest temperature outside the Arctic was officially recorded: -68°C, and in 1900 - in Tomsk: -55°C. Siberia is traditionally considered a place of hard labor and exile, unsuitable for normal human life. Severe frosts occur here two or three times every century. The further east, the harsher winter. The reason is the East Siberian anticyclone, i.e., a vast area of ​​high pressure created by a surface layer of cold, dry and heavy arctic air. In 2006, a cold front began moving westward in the first half of January, when in Novosibirsk the temperature dropped from –5 to –31° C in just 9 hours. By the night of January 11, in the vicinity of Omsk the temperature dropped to –47° C. On 1700 km to the west, in Moscow, frosts also came in January 2006. The average January minimum here is about –16° C, but passing over the capital of Russia, the cold front dropped the temperature to a record –37° C. Moreover, such frosts lasted for almost a week. During this week of severe frosts, the number of victims of hypothermia in Moscow exceeded a hundred. Then the cold front moved to Belarus, Ukraine, Romania (below –25°C), and the Czech Republic (below –30°C). Ukraine was hit the hardest: hypothermia claimed at least 130 lives, and more than 500 patients were admitted to hospitals with hypothermia and frostbite. In southern Russia, overnight frosts hit tea plantations hard and killed many palm trees in Black Sea resorts. In the Crimean naval port of Sevastopol, the sea froze for the first time in 60 years. However, the most severe frosts in the same year in the first days of February were noted in Buryatia, in Magadan, where night temperatures dropped to -60°C. Local television stations reported many fires caused by overloaded wiring due to the mass activation of electric heaters. One of the main high-voltage lines has failed.

Frosts paralyze the life of cities, have a detrimental effect on crops, and increase the likelihood of technical accidents (at temperatures below –30°C, the fragility of machine parts increases significantly).

Extreme intrusions of cold masses, usually accompanied by snowfalls, can be relatively short-lived (a few days), but they are destructive to agricultural crops in subtropical zone, and in spring in the southern part of the temperate climate zone. In addition, they complicate the life of cities, the work of communications, etc.

The phenomenon of air temperature dropping below 0°C in the evening and at night after a day with positive temperatures is called frosts. In the European part of Russia, frosts usually occur in spring or autumn when cold air masses invade or an anticyclone arrives, during which intense nighttime thermal radiation from the earth's surface cools the soil, vegetation and air. Frosts cause a lot of damage agriculture, especially in low-lying areas where cold air can stagnate. To combat frost, fires are used that produce smoke that covers earth's surface and protects it from cooling.

Extreme heat in any climatic zone is established during the summer anticyclone. Absolute maximum temperature – Maximum temperature air recorded at a given point, country or on Earth as a whole over the entire history of meteorological observations. So, for Moscow this value is 38.2 °C (July 29, 2010), the previous record was recorded on August 7, 1920, was 36.8 °C. For globe 57.8 °C (Libyan Desert).

In August 2003, the air temperature in Paris reached +41°C. In Spain, the thermometer showed temperatures in some places above +45°C. The asphalt stuck to the tires and the plastic soles melted. Abnormal heat was brought to France by a change in atmospheric circulation over the North Atlantic. During the “heat wave,” photochemical smog hung over the city. At this temperature, the human body cools by secreting sweat and pumping blood closer to the surface of the skin. If the temperature and humidity remain abnormally high for a long time (from August 1 to August 20), then overheating of the body occurs (hyperthermia). Thus, according to the French Institute of Health and Medical Research, the unprecedented heat of August 2003 led to the death of 17,802 people. Portugal was particularly hard hit, where fire destroyed 40% of forests, killed 18 people and devastated great amount farms Grains burned out, fruit fell from withering trees, livestock tramped restlessly on withered pastures, millions of birds died. The water level in the Danube has reached a record low, and it has become scarce for cooling nuclear power plant reactors.

By the end of August, the “heat waves” were replaced by cool northern air. Collision atmospheric fronts led to severe thunderstorms and hail the size of quail egg. Lightning set dry trees on fire, but within minutes the fire was doused with a long-awaited downpour.

The summer of 2010 in the European part of Russia turned out to be the warmest in 1000 years. For more than 2 months, almost every day it was 7 degrees above the average. Such temperatures (38.2 °C), in which Russians are forced to survive, are typical for the Sahara. Russia lost about 10 million hectares of grain crops, more than 120 thousand hectares of forest, and mortality in many regions doubled. 17 regions of Russia were engulfed in fires. 50 people died, over 3.5 thousand people were left homeless. The damage is estimated at billions of rubles. It was also unbearably hot in Japan, Canada, the USA, and Western Europe. Pakistan has experienced its worst flooding in 80 years. Most meteorologists are confident that these phenomena at the global level represent links in one chain. According to the deputy director of the Hydrometeorological Center, a so-called blocking anticyclone hovered over Russia, which did not allow the passage of colder and more humid air from the Atlantic. Scientists have no answer why this happened, “such changes are part of the natural variability of the atmosphere.” According to forecasts from the British Meteorological Service, such heat will recur every two to three years. Everyone is talking about the gradual warming of our planet, the increase in natural anomalies, including “summer heat waves.”

Heat leads to drying out of the soil, an increase in fire danger in forests, steppes, peatlands, shallowing of navigable rivers and other undesirable consequences in areas stretching many hundreds of kilometers.

A significant lack of precipitation for a long time in spring or summer at elevated air temperatures is called drought, as a result of which the moisture reserves in the soil are greatly reduced, plants develop poorly, and the crop may die completely.

Drought- a common occurrence in tropical latitudes, semi-deserts and especially steppe zones, where the main area of ​​arable land is located, in spring and summer due to the long-term (up to 2 months) dominance of anticyclonic weather.

Droughts occur when the atmosphere for a long time High air pressure remains, i.e. there is an anticyclone. Downdrafts in the atmosphere prevent rain from occurring, and clear weather leads to warming and drying of the air and soil.

Droughts have a negative impact on agriculture and forestry, domestic and industrial water supply, shipping and hydroelectric power station operation. They can be assessed, accordingly, by various geophysical indicators - from precipitation deficit (in magnitude, duration, distribution) to complex coefficients, including deviations from the norm in air temperature, precipitation, moisture reserves in the soil, as well as economic indicators crop shortages, losses in hydroelectric power production, etc. Droughts are created by a deviation of the pattern and intensity of atmospheric circulation from the norm for reasons related to fluctuations in solar activity and self-oscillations in the ocean-atmosphere system, especially in energy-active zones (El Niño and others ). As a rule, severe droughts in some areas are accompanied by increased precipitation in others.

Drought is also called dry wind. Sukhovey– a hot or very warm wind, observed in steppes, semi-deserts and deserts. It contributes to the destruction of grain and fruit crops. Dry winds blow in Northern Kazakhstan, the steppes of Russia and Ukraine.

Droughts are almost always accompanied by both dry winds and dust storms, which increase the evaporation of moisture from the soil surface, so the fight against droughts, hot winds and dust storms involves the accumulation of moisture in various soils. For this purpose, snow retention is carried out, forest shelterbelts, ponds and reservoirs are created in ravines and ravines, soil harrowing and other agricultural measures are organized.

Persistently dry and arid areas include 40-45% of the continents' area; More than 1/3 of the world's population lives here. In areas where droughts are possible at least occasionally, 3/4 of the population is located. For the main agricultural regions of Russia, droughts are caused by the anomalous development of anticyclones of Arctic and subtropical origin, blocking the usual paths of Atlantic cyclones.

Severe droughts occur around the world almost every year. In terms of the number of victims and economic damage, they are in the top five types of emergency situations; in terms of the largest single number of victims (more than 1 million in India in 1965–1967) and the magnitude of direct economic damage (tens of billions of dollars), they are among the largest emergency situations.

Most emergencies are fortunately short-lived. An earthquake usually lasts no more than a minute. A tornado passes over the city in just five minutes. Cyclones and hurricanes rage over cities for an hour. Even the duration of floods is measured in just a few days.

But things are completely different with drought and the resulting famine. These emergencies can last for weeks, and their consequences leave their mark on entire generations.

There are four main types of drought :

Constant drought characteristic of deserts - places with an arid climate where plants do not grow without irrigation.

Seasonal drought typical for climatic zones with distinct dry and rainy seasons.

Unpredictable drought occurring when there is an unexpected decrease in precipitation.

Invisible drought which is a borderline state when high temperatures promote increased evaporation and transpiration, so that even regular rains are not able to sufficiently moisten the soil, and the crop dries up on the vine.

Drought as a natural phenomenon often leads to famine. This is a natural cause of famine, beyond human influence, and is sometimes found outside the affected areas. The sources may dry up main river supplying water to vast areas. The sources of the river can be located hundreds of kilometers from the place of drought, even in another state. Famine often visits Lower Egypt and the Middle East, whose natural conditions are not suitable for intensive settled agriculture. The springs that bring water to these places are located many kilometers away.

China and India are the countries most prone to drought in the world. In India, in the summer of 1987, about 250 million people experienced a lack of drinking water; many hydroelectric power stations sharply reduced or stopped generating electricity. A drought in the summer of 1976 in South Wales caused famine in England. South Wales is generally subject to heavy downpours, fog and incessant rain. By the end of May, the harvest began to dry up in the fields throughout England. In Russia, droughts most often affected the Middle and Lower Volga regions and the river basin. Ural. The driest years were 1891, 1911, 1921, 1931, 1936, 1946, 1954, 1957, 1967, 1971, 1972, 1975. At the beginning of 1990, the scarcity of winter precipitation in the subtropics of the Mediterranean gave rise to drought and a shortage of water for domestic water supply. Droughts lead to the process of desertification - a decrease in the productivity of cultivated lands and pastures under the influence of their anthropogenic overload. About 100 countries and 12% of the world's population suffer from the onset of deserts; on average, 5–7 million hectares of land per year are subject to desertification. In general, deserts and desertified lands occupy more than 1/5 of the territories of inhabited continents. More than 850 million people live there.

Microclimate parameters have a direct impact on a person’s thermal well-being. It has been established that at air temperatures above + 25 ° A person’s performance begins to decline. The maximum temperature of inhaled air at which a person is able to breathe for several minutes without special protective equipment is about +116°C.

A person's tolerance to temperature largely depends on the humidity and speed of the surrounding air. The more relative humidity, the less sweat evaporates per unit time and the faster the body overheats. High humidity at temperatures above + 30 °C has a particularly unfavorable effect on a person’s thermal well-being, since in this case almost all of the heat released is transferred to environment when sweat evaporates. Together with sweat, the body loses a significant amount of mineral salts. Under unfavorable conditions, fluid loss can reach 8–10 liters per shift and with it up to 40 g of table salt (in total there is about 140 g of NaCl in the body). At high air temperatures, carbohydrates, fats, and proteins are consumed.

To restore water intake, a person needs to be fed with salted (about 0.5% NaCl) carbonated water. drinking water at the rate of 4–5 liters per person per day. In hot weather climatic conditions It is recommended to drink chilled drinking water or green tea.

Long term exposure high temperatures, especially in combination with high humidity, can lead to a significant accumulation of heat in the body and the development of overheating of the body above the permissible level - hyperthermia. This is a condition in which the body temperature rises to 38–39 °C. With hyperthermia, and as a result, heat stroke, headache, dizziness, general weakness, distortion of color perception, dry mouth, nausea, vomiting, profuse sweating, rapid pulse and breathing. In this case, there is pallor, loss of consciousness, and the pupils are dilated.

Finding a person reduced temperature, high air mobility and humidity, can cause cooling and even hypothermia of the body - hypothermia. With prolonged exposure to cold, breathing becomes irregular, the frequency and volume of inhalation increase. The appearance of muscle tremors, in which external work is not performed and all energy is converted into heat, can delay the decrease in temperature for some time internal organs. The result of low temperatures is “cold” injuries (Box 15).

Box 15

In India in January 1989 and in Mexico in January 1984, more than 200 people died from cold at temperatures around 0 ° C; in January 1984 and February 1989 in the USA, frosts down to –40°C killed 230 people and caused enormous damage to agriculture and transport. Overall, in the United States, extreme cold ranks second among all causes of emergencies in terms of economic damage. Globally, average annual damage from frost and snowfall ranks fifth after damage from hurricanes, floods, earthquakes and droughts.

The mortality rate of elderly and sick people, according to studies in England, the USA, and India, increases significantly both during frost and heat, and the temperature deviation from the norm is more significant than its absolute value. The rate of cooling or warming also matters: when sudden changes Temperatures increase the number of car accidents by 25% during cold weather, and by 56% during hot weather. With a heat of only 37°C in Central England in July 1990, the runways of airfields were deformed, the rails on railways. In Burkina Faso (Africa), at approximately the same time, due to extreme heat (up to 50 ° C in the shade), an ammunition depot exploded due to overheating of the walls.

According to Decree No. 370 of December 16, 2010 on the organization of work in the cold season in the open air and closed unheated rooms on the territory Tomsk region work is suspended if the wind speed and air temperature have the following parameters:

Means of protection at high and low air temperatures are as follows: to protect against the adverse effects of climatic factors, they are used the following types personal protective equipment: overalls, safety shoes, hand protection and hats.

Overalls for protection from low temperature, wind and atmospheric precipitation It is made from cotton fabrics with water-repellent and other impregnations, from natural or artificial fur and synthetic insulation. Especially great importance has the quality of workwear for working outdoors in the Far North. Electric heating kits “Penguin”, “Raccoon”, etc. have been developed.

Thus, the general circulation of the atmosphere in combination with solar radiation determines the location of vast areas of anticyclones and cyclones and reflects the characteristics of atmospheric circulation. Natural disasters of a meteorological nature are considered: tropical cyclones (hurricanes, typhoons) and mid-latitude cyclones, squalls and tornadoes (tornadoes), extreme precipitation and snow-glacial phenomena, thunderstorms, hail, extreme air temperatures and protection from them.

Questions for self-control

1. Give general characteristics natural phenomena in the atmosphere according to the classification?

2. Give characteristics of mid-latitude cyclones and tropical cyclones?

3. Describe squalls and tornadoes?

4. What are the actions of the population in the face of the threat of a hurricane or storm?

5. Indicate the existing extreme precipitation and snow-glacial phenomena in Russia and their impact on human life?

6. Give a description of thunderstorms, hailstorms and protection from the danger emanating from them?

7. What are extreme air temperatures and their impact on human life?

HAZARDOUS NATURAL PROCESSES IN THE HYDROSPHERE

Everything is good in nature, but water is the beauty of all nature. Water is alive, it runs or is agitated by the wind; it moves and gives life to everything around it. The phenomena are diverse and the laws of this diversity are not clear.

S.T. Aksakov

Protection of the population and territories from natural Disasters has been relevant at all times. Natural disasters in the hydrosphere include processes that lead to the death of people and ecosystems. The types of hazardous hydrological and hydrogeological processes, according to GOST R 22.0.06–95, include: tsunamis, floods, flooding, erosion, inundation, karst, suffusion, salinization, swamping, subsidence of loess-like rocks, quicksand, swelling. The chapter examines the most common marine and continental hazardous hydrological processes and protection against them: tsunamis and floods. The following literature was used in writing this chapter.

& KEY TERMS . Tsunamis, floods, flooding, erosion, inundation, karst, suffusion, salinization, swamping, subsidence of loess-like rocks, quicksand, swelling .

As indicators of variability of extreme events on the territory of Russia, we used the total for winter or summer period the number of cases (days) when the daily air temperature or the amount of precipitation exceeded the critical value.

In winter, the number of days with maximum temperatures exceeding the limit values ​​increases in most of the European territory of Russia (except for the southern and southeastern regions) and in Western Siberia (Fig. 1). In the east of the country, excluding the Pacific coast of Chukotka and Kamchatka, there is also an increase in extremes in the winter maximum daily air temperature.

In winter, at most of the stations studied, a tendency was revealed to reduce extremeness in the regime. minimum temperatures for the period from 1961 to 1998. Moreover, the maximum (in absolute value) values ​​of the linear trend coefficients were obtained in the south of the country and in the east of Yakutia.

Rice. 1. Linear trend coefficient (days/10 years) in the series of the number of days with abnormally high air temperatures in winter (December-February). 1961-1998

Based on data for the period 1966-1998. an increase in the extremeness of winter precipitation was detected at stations in the European territory of Russia north of 55° N. latitude. and in the center of Siberia. An increase in the number of days with extreme winter precipitation is also observed at Chukotka stations. When considering extremes in temperature summer season It was found that at stations in the eastern part of the European territory of Russia, in the center of Siberia, in Yakutia and in the east of the country, the number of days when the maximum temperature exceeds the limit value is increasing. At the same time, most stations in Russia received negative values linear trend coefficient in series of the number of cases of extremely low minimum temperatures. Only at a few stations in the northeast of the country was a trend of increasing extremes associated with very low air temperatures detected. At a number of stations in the southern regions of the country, trends of decreasing extremes associated with both maximum and minimum temperatures were identified.

On the territory of Russia, an increase in the number of days with extreme summer precipitation prevails (Fig. 2). Only at some stations in the center of Siberia, in the Magadan region and in the Primorsky Territory, negative values ​​of linear trend coefficients were obtained.

Rice. 2. Linear trend coefficient (days/10 years) in the series of the number of days with abnormally high precipitation in summer (June-August). 1966-1998

Extremeness assessment temperature regime and precipitation regime in Russia in 2002.

JANUARY 2002

The entire southern half of Russia is covered by a zone where there were more than 5 days with extremely high air temperatures for that month. And on European territory and in the Central regions of Western and Eastern Siberia highlighted where there were more than 10 such days with extremely high temperatures (Figure 3.).

Figure 3. Number of days with extremely high (Nmax) and extremely low (Nmin) air temperatures in JANUARY in Russia.

In January, the number of days with precipitation exceeding the value of the 95% interval limit exceeded the long-term average value by more than two standard deviations in the north of the Volga-Vyatka region. Heavy snowfalls were also observed in the south Tyumen region and in the central regions of Yakutia (Figure 4.)

Figure 4. Number of days with extremely high precipitation (Nr) in JANUARY 2002 in Russia.

FEBRUARY 2002

On European territory In Russia, February was characterized in the same way as the previous month big amount extremely warm days. And in the central regions of Western Siberia, Krasnoyarsk Territory, in the north of the Irkutsk region and Transbaikalia there is an area where extremely high air temperatures for February occurred for more than 10 days (Figure 5.).

Figure 5. Number of days with extremely high (Nmax) and extremely low (Nmin) air temperatures in FEBRUARY in Russia.

In February, the field of spatial distribution of the number of cases with extreme precipitation is very close to January (Figure 6.).

Figure 6. Number of days with extremely high precipitation (Nr) in FEBRUARY 2002 in Russia.

MARCH 2002

Despite the fact that March was warm throughout almost the entire territory of Russia, not many days with extremely high temperatures were recorded (Figure 7).

Figure 7. The number of days with extremely high (Nmax) and extremely low (Nmin) air temperatures in MARCH in Russia.

In the field of extreme precipitation there is a vast zone that covers the Urals, almost the entire Western Siberia, central and southern regions of the Krasnoyarsk Territory. And in the east of the country - in the Magaden region and Chukotka, the number of days with extremely high precipitation exceeded the long-term average by more than the average standard deviation(Figure 8.).

Extreme amounts and duration of precipitation can be hazardous to people and objects.

Frontal showers last from several hours to 4 days, with breaks of 2-3 weeks, and cover areas of up to hundreds of thousands of square kilometers. Most often, a rainstorm lasts 5-10 hours, and the annual norm of precipitation can fall in 10-20 hours.

Snow cover is a layer of snow on the surface of the earth resulting from snowfall. There is a distinction between temporary and permanent snow cover. Stable snow cover is spreading in areas with average temperature the coldest month is O °C and below, unstable snow cover and rare snowfalls are possible at a temperature of this month of 10-12 °C.

The amount of snow cover characterizes the snowiness of winter. Based on absolute snow content, the following are distinguished: snowless areas, where the snow cover thickness is less than 10 cm; little snow - with a cover of 10-30 cm, in continental regions - up to 50 cm; multi-snow - with a snow cover height of more than 50 cm.

Blizzard (blizzard) is the transfer of snow strong wind above the surface of the earth. The amount of snow transported is determined by the wind speed, and the areas where snow accumulates are determined by its direction. Weak snowstorms spread at a speed of 20 m/s and last for several days, strong snowstorms with a speed of 20-30 m/s last up to several hours. In the European part of Russia, the average number of days per year with a snowstorm is 30-40, average duration snowstorms - 6-9 hours, of which only 5-6 are the strongest snowstorms.

hail - precipitation in the form of ice balls and a mixture of ice and snow. Fall during the passage of a cold front or during a thunderstorm from powerful cumulonimbus clouds. In temperate latitudes, hail falls 10-15 times a year, causing destruction and loss of life.

When clear anticyclonic weather persists for an unusually long time, and in the temperate climate zone and in the subtropics, also with the invasion of cold air masses from higher latitudes, extreme air temperatures are established.

Extreme heat in any climate zone occurs during a summer anticyclone that is unusual in location or duration. It leads to desiccation, growth fire danger, to the shallowing of navigable rivers and to other undesirable consequences over vast territories.

In the summer of 2010, Russia experienced an abnormal heat wave caused by the abnormally long presence of the anticyclone in the European part of the country - from June 21 to August 19. The central part of Russia remained without precipitation for two months; abnormally high temperatures were recorded there, never recorded during the entire period of instrumental observations. In Moscow alone in the summer of 2010, 22 temperature records were broken (two in June, 10 in July and 10 in August). The daily maximum air temperature in the city during the heat wave did not fall below 30°C for 33 consecutive days (from July 14 to August 15 inclusive).

A significant lack of precipitation for a long time in spring or summer at elevated air temperatures is called drought, as a result of which the moisture reserves in the soil are greatly reduced, plants develop poorly, and the crop may die completely.

Drought is a fairly common phenomenon in tropical latitudes, semi-desert and especially steppe zones, where the main area of ​​arable land is located, in spring and summer due to the long-term dominance of anticyclonic weather.

Sometimes drought is accompanied dry wind - hot or very warm wind, mainly in steppes, semi-deserts and deserts.

Droughts are almost always accompanied by both hot winds and dust storms, which increase the evaporation of moisture from the soil surface, so the fight against droughts, hot winds and dust storms involves the accumulation of moisture in various soils.

Severe droughts occur around the world almost every year. In terms of the number of victims and economic damage, they are in the top five types of emergency situations.

There are four main types of drought:

• constant drought characteristic of deserts - places with an arid climate where plants do not grow without irrigation;
• seasonal drought typical for climatic zones with clearly defined dry and rainy seasons;
• unpredictable drought, occurring with an unexpected decrease in precipitation;
• invisible drought is a borderline condition when high temperatures promote increased evaporation and transpiration, so that even regular rains are not able to sufficiently moisten the soil, and the crop dries up on the vine.

Droughts strongly push the process of desertification - a decrease in the productivity of cultivated lands and pastures under the influence of their anthropogenic overload. About 100 countries of the world and 12% of the world's population suffer from the onset of deserts; on average, 5-7 million hectares of land per year are subject to desertification. In general, deserts and desertified lands occupy more than 1/5 of the territory of inhabited continents and are home to more than 850 million people.

Extreme frosts in temperate zone are installed during anticyclonic weather, paralyzing the life of cities and having a detrimental effect on crops.

The phenomenon of air temperature dropping below 0°C in the evening and at night after a day with positive temperatures is called frosts. In the European part of Russia, frosts usually occur in spring or autumn, when cold air masses invade or an anticyclone arrives, during which intense nighttime thermal radiation from the earth's surface cools the soil, vegetation and air.

Frosts cause quite serious damage to agriculture. To combat frost, fires are used that produce smoke that covers the earth's surface and protects it from cooling.

Extreme air temperatures can cause both relatively minor socio-economic losses and real emergencies. The nature and extent of damage depend not so much on the magnitude of the deviations themselves, but on the adaptability of people and objects to such conditions.

Globally, average annual damage from frost and snowfall ranks fifth after damage from hurricanes, floods, earthquakes and droughts.

Protecting the population from natural hazards and threats is one of the primary tasks of the Ministry of Emergency Situations, however, every person must clearly know and follow the rules of safe behavior in the event of sudden extreme precipitation and a decrease (increase) in temperature before help arrives.

Air temperatures below minus 70 °C are observed only in a few regions of the Earth. The undoubted leadership here is held by Antarctica, where the lowest air temperature on the planet was recorded at Vostok station - minus 89.2 °C. In the Northern Hemisphere, such frosts are impossible, and the absolute minimum is considered to be a temperature of minus 77.8 ° C, observed in the Oymyakon region. The air temperature on some glaciers in Greenland can also drop below minus 70 °C.
Of course, such extreme temperature values ​​are typical primarily for the interior regions of Antarctica and, to a lesser extent, Greenland, where the conditions are sharply continental. high mountain climate are combined with a long polar night and a constant outflow of heat from these areas. It is interesting that, for example, in the vicinity of Vostok station in the summer, over 30 thousand calories of solar heat are received for every square centimeter of the surface. This is almost double what Tbilisi receives in July. But about 90%, and in individual days up to 98% of all solar rays arriving on the snow surface are reflected from it, like from a mirror. During the polar night, Antarctica receives no solar heat at all. This means that in its inland regions there is continuous cooling of the surface layers of the ice sheet. The unlimited increase in frost is limited by the influx of heat from the depths of the Earth and the continuous mixing of air masses.

What is the human condition in conditions of ultra-low temperatures? At temperatures below minus 70 °C, staying in the open air for more than 10-15 minutes, even in special climate clothing, is difficult due to the risk of frostbite of the extremities and respiratory tract. So, at a temperature of minus 70 ° C and a wind of 5 m/sec, within 10-13 seconds the bare hands begin to hurt very much, and after 35-40 seconds numbness and numbness sets in. Heat loss from the surface of the respiratory organs increases several times due to the heating of frosty air and its humidification, since in Central Antarctica absolute humidity air in winter approaches zero.
Calculations show that almost half of the total heat transfer from the body occurs through the respiratory organs. The heat transfer is so intense that it can cause direct hypothermia and frostbite of the lungs. After breathing frosty (below minus 70 ° C) air, raw chest pain and a painful dry cough appear, which lasts 2-5 hours, and sometimes spasms of the vocal cords.

B.C. Ignatov, head of Vostok station in 1959-1960. This is how he describes the feelings of a person who has been in the cold of minus 85.7°C: “The weather was clear. A dazzlingly bright disk of the sun stood above the horizon. A steady breeze blew from the northwest. Its speed was low - only 5 meters per second. But even with such a weak wind, the frost was incredibly fierce, it burned like fire, and breathed truly cosmic cold. Despite the haze, the sun's disk was clearly visible above the horizon. There was a dark purple wall of frosty fog in the air. Within a minute, the scarf, damp from breathing, turned into a real spacesuit. The frost penetrated to the bones. Warm didn't help either special clothing. Your hands turned white instantly, as soon as you pulled them out of your mittens. If you take up anything, frost will hit your hands, as if electricity. The joints of the fingers, even hidden in the mittens, hurt unbearably, as if they were squeezed with terrible force. After 8 minutes, my legs, shod in high boots and warm woolen socks, lost sensitivity. An uncontrollable cough began: the deadening frost made its way to the lungs. Further experiments became dangerous, and we had to retreat. Returning to the house, I coughed for a long time, coughing up mucus from my chilled lungs. I felt slightly dizzy, shortness of breath increased, I felt weak and dry in the mouth.”

Ultralow temperatures affect the state and structure of many familiar substances and materials. Thus, the results of experiments carried out at the Vostok station on the outflow of diesel fuel and aviation gasoline at different temperatures air. 3-meter horizontal tubes with a diameter of 10 millimeters were soldered to two tanks with a capacity of 15 liters each. 10 liters of diesel fuel were poured into one of the tanks, and the same amount of aviation gasoline into the other, and the time of complete exhaustion of the fuel was measured. The experimental results are shown in the table.

The effect of ultra-low temperatures on some substances:

Another interesting experience. In the cold of -80 °C, a burning torch was brought to the surface of gasoline, but not only did it not ignite it, gasoline practically does not evaporate at such low temperatures. Kerosene already at a temperature of minus 60°C turns into a thick snow mass, and at minus 85° it hardens; Diesel oil at temperatures below 75° becomes so hard that it has to be chopped with an axe. Antifreeze at 85° turns into pinkish ice, rubber hoses and wires are destroyed by the slightest bend. In order to cut out the bottom of an iron barrel, three or four blows of an ax are enough - at temperatures below 85°, the iron becomes brittle and, like glass, breaks into pieces. Even the ice sheet cannot withstand such severe frost. Under the influence of low temperatures, so-called thermal explosions occur, accompanied by powerful rolling sounds reminiscent of thunder - this is the cracking and destruction of the glacial shell of Antarctica.

Wintering at Vostok station, where ultra-low temperatures air - the norm, becomes a real test for polar explorers. Despite the relatively low altitude above sea level at which the station is located, acclimatization is very difficult and the physiological reserves of the body are almost constantly depleted. New arrivals are forced to move as little as possible, sometimes just lie down all the time. It’s as if a huge weight is pressing on a person, not allowing him to breathe freely. Those loads that could easily be lifted by one person in Mirny are carried by two or three people in the East.
One day a dog was brought to the East. The dog, named Volosan, frolicked at first, studied the station, ran, not knowing that this could not be done in the East. However, he soon understood everything - acclimatization began. The dog did not eat anything, he was shaking. For days on end Volosan lay in a sleeping bag where the polar explorers had stuffed him, looked at everything with a dull gaze and melted right before his eyes. On the seventh day he became very ill and had to be sent back to Mirny. He could no longer walk to the plane on his own - the polar explorers carried him in a sleeping bag.

Climbers, found among polar explorers, who have visited the Pamirs and Tien Shan, sometimes treat the height of the East (some three and a half thousand meters) without due respect. However, this condescending tone disappears in the very first minutes of his stay in the East. Evacuation from the station of people who seemed completely healthy is, in general, not uncommon. From the beginning of the Antarctic autumn - in March and until December - communication with the East is possible only by radio. Those wintering at the station during these eight or even nine months have to rely solely on their own strength. No matter what happens, help will not be able to come.

April 12, 1982 is the most terrible day in the history of the East. The diesel power plant burned down, and the head of the diesel power plant, A.I., died in the fire. Karpenko. In this ten-degree frost, the station lost its source of heat and light. Several months of the hardest winter lay ahead. The fire happened at night. They tried to stop the fire with fire extinguishers, snow, and tarpaulins. It was all in vain. Soon the power plant stopped. No heat, no light, no radio communication. Frost below seventy. Only the flames of fire illuminate the East. The polar explorers are powerless to do anything - the wind fans the fire, and the fuel containers that were in the diesel tank burst into flames. Several tons of burning oil and diesel fuel. A pillar of fire and smoke rises tens of meters above the station. Now, if it is not possible to establish radio communication, they will learn about what happened in the East from satellite images. But even after learning about the fire, no one will be able to help the winterers of the East. Meanwhile, the wind began to push the flames down onto the main fuel supply - 300 tons of diesel fuel. There is also a kerosene tank nearby. Behind the tanks is almost the entire supply of food for the year. If all this catches fire, the polar explorers will have no chance of survival. However, at that moment there was no time to weigh the chances. Even the ten-degree frost was doing its job. Very soon the walls of the premises were covered with frost. It won't be long before the station completely freezes over. If you don't cope with the cold now, death is inevitable. It was necessary to immediately provide at least a little warmth in any way. In the memories of polar explorers, this night appears as some kind of endless crazy carousel. They rushed to make and install drip stoves, knock out holes in the walls of houses to remove pipes from the stoves, drag food, medicines and solutions afraid of the cold. Finally, fate had mercy on them - the wind changed, the flames were carried away from the fuel containers that were ready to explode. We warmed the house with the radio, preventing the radio station from freezing. We managed to start an old small diesel engine that no one had touched for a long time. This already weak engine at the altitude of the East lost a third of its power, but still the electricity it generated was enough to revive the transmitter. We managed to report what had happened, after which the connection was interrupted.

Although on Mainland developed various rescue plans and tried their best to help people in trouble, it soon became clear that there was no real possibility for this purpose no. Twenty polar explorers at Vostok station had to endure the longest and most severe winter on Earth.

What kind of wintering it was like can be judged by the conditions in which they had to be. They lived in terrible cramped conditions - at first, until the bunks were made, they even took turns sleeping. Although the drips somehow warmed the rooms, they did it extremely unevenly - it was relatively warm at the top, but ice froze on the walls and under the beds. We slept in full polar gear, without taking off our high boots, wrapping our heads in a scarf so that if we accidentally touched the wall, our hair would not freeze.

The stoves smoked terribly, covering everything around with a layer of greasy soot and soot. The engine was unreliable; it was only turned on for two hours so that the radio station could work. The rest of the time, the only source of light was homemade candles. The polar explorers built a bathhouse, but you could only wash in it with rubber boots, otherwise your feet would freeze to the floor. The winterers lost almost their entire supply of vegetables, which nevertheless froze or rotted. Some of the canned food also became unusable - many glass jars could not be saved from the frost, and they burst. We had to save water - after the fire there was no clean snow left around the station within a radius of several hundred meters. It was precisely this distance that the duty officer had to go to for snow every day and make more than one trip. And this is in the East, where every step is difficult for a person! And this is at an air temperature that was consistently around seventy degrees, and in August the frosts exceeded eighty!

During this wintering, polar explorers inevitably had to violate all safety standards and instructions dozens of times, forcing Once again marvel at the hidden capabilities of the human body. What is the cost of just one night during a fire? It’s hard to believe, but people spent several hours outdoors at a temperature of about minus 70 ° C (20-25 minutes is considered the norm). At the same time, at first, many of them, raised in the middle of the night, were only somehow dressed. Moreover, that night there was no hypothermia or frostbite. The polar explorers later said that they didn’t even feel the frost.

Being in such an extreme situation, the human body mobilized all its internal forces. The winter that followed also seemed to be on the verge of human capabilities, but people in these conditions not only survived, but continued the same work that they had been doing before the fire. The very next day, the Vostok radio station broadcast two weather reports. Ultimately, it was the fact that people did not give up, did not succumb to despair and apathy, that helped them survive the Antarctic winter at the Pole of Cold.