Earth atmosphere. Layers of the atmosphere in order from the surface of the earth

Earth's atmosphere is the gaseous envelope of our planet. Its lower boundary passes at the level of the earth's crust and hydrosphere, and the upper one passes into the near-Earth region. outer space. The atmosphere contains about 78% nitrogen, 20% oxygen, up to 1% argon, carbon dioxide, hydrogen, helium, neon and some other gases.

This earth shell is characterized by clearly defined layering. The layers of the atmosphere are determined by the vertical distribution of temperature and the different density of gases at its different levels. There are such layers of the Earth's atmosphere: troposphere, stratosphere, mesosphere, thermosphere, exosphere. The ionosphere is distinguished separately.

Up to 80% of the total mass of the atmosphere is the troposphere - the lower surface layer of the atmosphere. The troposphere in the polar belts is located at a level of up to 8-10 km above earth's surface, V tropical zone- up to a maximum of 16-18 km. Between the troposphere and the overlying stratosphere is the tropopause - the transition layer. In the troposphere, temperature decreases with increasing altitude, similarly decreases with altitude Atmosphere pressure. The average temperature gradient in the troposphere is 0.6°C per 100 m. different levels of this shell is determined by the features of absorption solar radiation and efficiency of convection. Almost all human activity takes place in the troposphere. Most high mountains do not go beyond the troposphere, only air transport can cross the upper boundary of this shell to a small height and be in the stratosphere. A large proportion of water vapor is contained in the troposphere, which determines the formation of almost all clouds. Also, almost all aerosols (dust, smoke, etc.) that form on the earth's surface are concentrated in the troposphere. In the boundary lower layer of the troposphere, daily fluctuations in temperature and air humidity are expressed, the wind speed is usually reduced (it increases with altitude). In the troposphere, there is a variable division of the air column into air masses in the horizontal direction, which differ in a number of characteristics depending on the zone and the area of ​​their formation. On atmospheric fronts- the boundaries between air masses - cyclones and anticyclones are formed, which determine the weather on certain territory during a specific period of time.

The stratosphere is the layer of the atmosphere between the troposphere and the mesosphere. The limits of this layer range from 8-16 km to 50-55 km above the Earth's surface. In the stratosphere, the gas composition of air is approximately the same as in the troposphere. Distinctive feature– a decrease in the concentration of water vapor and an increase in the content of ozone. The ozone layer of the atmosphere, which protects the biosphere from the aggressive effects of ultraviolet light, is at a level of 20 to 30 km. In the stratosphere, the temperature rises with height, and temperature value determined by solar radiation, not by convection (movements air masses) as in the troposphere. The heating of the air in the stratosphere is due to the absorption of ultraviolet radiation by ozone.

The mesosphere extends above the stratosphere up to a level of 80 km. This layer of the atmosphere is characterized by the fact that the temperature decreases from 0 ° C to - 90 ° C as the height increases. This is the coldest region of the atmosphere.

Above the mesosphere is the thermosphere up to a level of 500 km. From the border with the mesosphere to the exosphere, the temperature varies from approximately 200 K to 2000 K. Up to a level of 500 km, the air density decreases by several hundred thousand times. Relative composition atmospheric components of the thermosphere is similar to the surface layer of the troposphere, but with increasing altitude large quantity oxygen goes into the atomic state. A certain proportion of molecules and atoms of the thermosphere is in an ionized state and distributed in several layers, they are united by the concept of the ionosphere. The characteristics of the thermosphere vary over a wide range depending on geographical latitude, quantities solar radiation, time of year and day.

The upper layer of the atmosphere is the exosphere. This is the thinnest layer of the atmosphere. In the exosphere, the mean free paths of particles are so huge that particles can freely escape into interplanetary space. The mass of the exosphere is one ten millionth of total weight atmosphere. The lower boundary of the exosphere is the level of 450-800 km, and the upper boundary is the area where the concentration of particles is the same as in outer space - several thousand kilometers from the Earth's surface. The exosphere is made up of plasma, an ionized gas. Also in the exosphere are the radiation belts of our planet.

Video presentation - layers of the Earth's atmosphere:

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STRUCTURE OF THE ATMOSPHERE

Atmosphere(from other Greek ἀτμός - steam and σφαῖρα - ball) - a gaseous shell (geosphere) surrounding the planet Earth. Its inner surface covers the hydrosphere and partially the earth's crust, the outer one borders on the near-Earth part of outer space.

Physical properties

The thickness of the atmosphere is about 120 km from the Earth's surface. The total mass of air in the atmosphere is (5.1-5.3) 10 18 kg. Of these, the mass of dry air is (5.1352 ± 0.0003) 10 18 kg, the total mass of water vapor is on average 1.27 10 16 kg.

The molar mass of clean dry air is 28.966 g/mol, the air density at the sea surface is approximately 1.2 kg/m 3 . The pressure at 0 °C at sea level is 101.325 kPa; critical temperature - -140.7 ° C; critical pressure - 3.7 MPa; C p at 0 °C - 1.0048 10 3 J/(kg K), C v - 0.7159 10 3 J/(kg K) (at 0 °C). The solubility of air in water (by mass) at 0 ° C - 0.0036%, at 25 ° C - 0.0023%.

For "normal conditions" at the Earth's surface are taken: density 1.2 kg / m 3, barometric pressure 101.35 kPa, temperature plus 20 ° C and relative humidity 50%. These conditional indicators have a purely engineering value.

The structure of the atmosphere

The atmosphere has a layered structure. The layers of the atmosphere differ from each other in air temperature, its density, the amount of water vapor in the air and other properties.

Troposphere(ancient Greek τρόπος - “turn”, “change” and σφαῖρα - “ball”) - the lower, most studied layer of the atmosphere, 8-10 km high in the polar regions, in temperate latitudes up to 10-12 km, at the equator - 16-18 km.

When rising in the troposphere, the temperature drops by an average of 0.65 K every 100 m and reaches 180-220 K in the upper part. This upper layer of the troposphere, in which the decrease in temperature with height stops, is called the tropopause. The next layer of the atmosphere above the troposphere is called the stratosphere.

More than 80% of the total mass is concentrated in the troposphere atmospheric air, turbulence and convection are highly developed, the predominant part of the water vapor is concentrated, clouds arise, atmospheric fronts form, cyclones and anticyclones develop, as well as other processes that determine the weather and climate. The processes occurring in the troposphere are primarily due to convection.

The part of the troposphere within which glaciers can form on the earth's surface is called the chionosphere.

tropopause(from the Greek τροπος - turn, change and παῦσις - stop, cessation) - a layer of the atmosphere in which the decrease in temperature with height stops; transition layer from troposphere to stratosphere. In the earth's atmosphere, the tropopause is located at altitudes from 8-12 km (above sea level) in the polar regions and up to 16-18 km above the equator. The height of the tropopause also depends on the time of year (the tropopause is higher in summer than in winter) and cyclonic activity (it is lower in cyclones and higher in anticyclones)

The thickness of the tropopause ranges from several hundred meters to 2-3 kilometers. In the subtropics, tropopause ruptures are observed due to powerful jet streams. The tropopause over certain areas is often destroyed and re-formed.

Stratosphere(from Latin stratum - flooring, layer) - a layer of the atmosphere, located at an altitude of 11 to 50 km. A slight change in temperature in the 11-25 km layer (the lower layer of the stratosphere) and its increase in the 25-40 km layer from -56.5 to 0.8 °C (the upper stratosphere layer or inversion region) are typical. Having reached a value of about 273 K (almost 0 °C) at an altitude of about 40 km, the temperature remains constant up to an altitude of about 55 km. This area constant temperature called the stratopause and is the boundary between the stratosphere and the mesosphere. The density of air in the stratosphere is tens and hundreds of times less than at sea level.

It is in the stratosphere that the ozonosphere layer ("ozone layer") is located (at an altitude of 15-20 to 55-60 km), which determines the upper limit of life in the biosphere. Ozone (O 3 ) is formed as a result of photochemical reactions most intensively at an altitude of ~30 km. The total mass of O 3 would be at normal pressure a layer with a thickness of 1.7-4.0 mm, but even this is enough to absorb the ultraviolet radiation of the sun that is harmful to life. The destruction of O 3 occurs when it interacts with free radicals, NO, halogen-containing compounds (including "freons").

Most of the short-wavelength part of ultraviolet radiation (180-200 nm) is retained in the stratosphere and the energy of short waves is transformed. Under the influence of these rays, magnetic fields, molecules break up, ionization occurs, new formation of gases and other chemical compounds. These processes can be observed in the form of northern lights, lightning and other glows.

In the stratosphere and higher layers, under the influence of solar radiation, gas molecules dissociate - into atoms (above 80 km, CO 2 and H 2 dissociate, above 150 km - O 2, above 300 km - N 2). At an altitude of 200-500 km, ionization of gases also occurs in the ionosphere; at an altitude of 320 km, the concentration of charged particles (O + 2, O - 2, N + 2) is ~ 1/300 of the concentration of neutral particles. IN upper layers atmosphere contains free radicals - OH, HO 2, etc.

There is almost no water vapor in the stratosphere.

Flights into the stratosphere began in the 1930s. The flight on the first stratospheric balloon (FNRS-1), which Auguste Picard and Paul Kipfer made on May 27, 1931 to a height of 16.2 km, is widely known. Modern combat and supersonic commercial aircraft fly in the stratosphere at altitudes generally up to 20 km (although the dynamic ceiling can be much higher). High-altitude weather balloons rise up to 40 km; the record for an unmanned balloon is 51.8 km.

IN Lately In the military circles of the United States, much attention is paid to the development of layers of the stratosphere above 20 km, often called the "pre-space" (Eng. « near space» ). It is assumed that unmanned airships and solar-powered aircraft (like NASA Pathfinder) will be able to stay at an altitude of about 30 km for a long time and provide observation and communication for very large areas, while remaining low-vulnerability to air defense systems; such devices will be many times cheaper than satellites.

Stratopause- the layer of the atmosphere, which is the boundary between two layers, the stratosphere and the mesosphere. In the stratosphere, temperature rises with altitude, and the stratopause is the layer where the temperature reaches its maximum. The temperature of the stratopause is about 0 °C.

This phenomenon is observed not only on Earth, but also on other planets with an atmosphere.

On Earth, the stratopause is located at an altitude of 50 - 55 km above sea level. Atmospheric pressure is about 1/1000 of the pressure at sea level.

Mesosphere(from the Greek μεσο- - “middle” and σφαῖρα - “ball”, “sphere”) - the layer of the atmosphere at altitudes from 40-50 to 80-90 km. It is characterized by an increase in temperature with height; the maximum (about +50°C) temperature is located at an altitude of about 60 km, after which the temperature begins to decrease to −70° or −80°C. Such a decrease in temperature is associated with the energetic absorption of solar radiation (radiation) by ozone. The term was adopted by the Geographical and Geophysical Union in 1951.

The gas composition of the mesosphere, as well as those of the lower atmospheric layers, is constant and contains about 80% nitrogen and 20% oxygen.

The mesosphere is separated from the underlying stratosphere by the stratopause, and from the overlying thermosphere by the mesopause. The mesopause basically coincides with the turbopause.

Meteors begin to glow and, as a rule, burn up completely in the mesosphere.

Noctilucent clouds may appear in the mesosphere.

For flights, the mesosphere is a kind of "dead zone" - the air here is too rarefied to support airplanes or balloons (at an altitude of 50 km, the air density is 1000 times less than at sea level), and at the same time too dense for artificial flights. satellites in such a low orbit. Direct studies of the mesosphere are carried out mainly with the help of suborbital meteorological rockets; in general, the mesosphere has been studied worse than other layers of the atmosphere, in connection with which scientists called it the “ignorosphere”.

mesopause

mesopause The layer of the atmosphere that separates the mesosphere and thermosphere. On Earth, it is located at an altitude of 80-90 km above sea level. In the mesopause, there is a temperature minimum, which is about -100 ° C. Below (starting from a height of about 50 km) the temperature drops with height, above (up to a height of about 400 km) it rises again. The mesopause coincides with the lower boundary of the region of active absorption of the X-ray and the shortest wavelength ultraviolet radiation of the Sun. Silvery clouds are observed at this altitude.

The mesopause exists not only on Earth, but also on other planets with an atmosphere.

Karman Line- height above sea level, which is conventionally accepted as the boundary between the Earth's atmosphere and space.

As defined by the Fédération Aéronautique Internationale (FAI), the Karman Line is at an altitude of 100 km above sea level.

The height was named after Theodor von Karman, an American scientist of Hungarian origin. He was the first to determine that at about this altitude the atmosphere becomes so rarefied that aeronautics becomes impossible, since the speed of the aircraft, necessary to create sufficient lift, becomes greater than the first cosmic speed, and therefore, in order to achieve higher altitudes, it is necessary to use the means of astronautics.

The Earth's atmosphere continues beyond the Karman line. The outer part of the earth's atmosphere, the exosphere, extends to an altitude of 10,000 km or more, at such an altitude the atmosphere consists mainly of hydrogen atoms that can leave the atmosphere.

Reaching the Karman Line was the first condition for the Ansari X Prize, as this is the basis for recognizing the flight as a space flight.

ATMOSPHERE - the gaseous envelope of the Earth, consisting, excluding water and dust (by volume), of nitrogen (78.08%), oxygen (20.95%), argon (0.93%), carbon dioxide (about 0.09%) and hydrogen, neon, helium, krypton, xenon, and a number of other gases (about 0.01% in total). The composition of dry A. throughout its entire thickness is almost the same, but the content increases in the lower part. water, dust, and soil - carbon dioxide. The lower boundary of A. is the surface of land and water, and the upper one is fixed at an altitude of 1300 km by a gradual transition into outer space. A. is divided into three layers: lower - troposphere average - stratosphere and top- ionosphere. The troposphere up to a height of 7-10 km (above the polar regions) and 16-18 km (above the equatorial region) includes more than 79% of the mass of the atmosphere, and (from 80 km and above) only about 0.5%. The weight of the A. column of a certain section at different latitudes and at decomp. temperature is slightly different. At a latitude of 45° at 0° it is equal to the weight of a mercury column of 760 mm, or the pressure per cm 2 1.0333 kg.

Complex horizontal (in different directions and at different velocities), vertical, and turbulent movements take place in all layers of air. Absorption of solar and cosmic radiation and self-radiation occur. Of particular importance as an absorber of ultraviolet rays is ozone in A. with a total content. only 0.000001% of the volume of A., but 60% concentrated in layers at a height of 16-32 km - ozone, and for the troposphere - water vapor that transmits short-wave radiation and delays the “reflected” long-wave radiation. The latter leads to heating of the lower layers of the atmosphere. In the history of the development of the Earth, the composition of the atmosphere was not constant. In the Archean, the amount of CO 2 was probably much greater, and O 2 - less, etc. Geochem. and geol. the role of A. as a container biosphere and agent hypergenesis very large. In addition to A. as a physical. body, there is the concept of A. as a technical quantity for expressing pressure. A. technical is equal to a pressure of 1 kg per cm 2, 735.68 mm mercury column, 10 m of water column (at 4°C). V. I. Lebedev.

Geological dictionary: in 2 volumes. - M.: Nedra. Edited by K. N. Paffengolts et al.. 1978 .

Atmosphere

Earth (from Greek atmos - steam and sphaira - * a. atmosphere; n. atmosphere; f. atmosphere; And. atmosfera) - a gaseous shell that surrounds the Earth and participates in its daily rotation. Macca A. is approx. 5.15 * 10 15 t. A. provides the possibility of life on Earth and influences the geol. processes.
Origin and role of A. Modern A. appears to be of secondary origin; it originated from gases released by the solid shell of the Earth (lithosphere) after the formation of the planet. During geol. history of the Earth A. has undergone means. evolution under the influence of a number of factors: dissipation (scattering) of gas molecules in space. space, the release of gases from the lithosphere as a result of volcanic. activity, dissociation (splitting) of molecules under the influence of solar ultraviolet radiation, chem. reactions between the components of A. and the rocks that make up the earth's crust, (capture) of meteoric matter. The development of A. is closely connected not only with geol. and geochem. processes, but also with the activities of living organisms, in particular humans (anthropogenic factor). The study of changes in the composition of A. in the past showed that already in early periods Phanerozoic amount of oxygen in the air was approx. 1/3 of its modern values. The oxygen content in A. increased sharply in the Devonian and Carboniferous, when it may have exceeded the modern. . After a decrease in the Permian and Triassic periods it rose again, reaching max. values ​​in Jurassic, after which there was a new decrease, k-poe is preserved in our . During the Phanerozoic, the amount of carbon dioxide also changed significantly. From the Cambrian to the Paleogene, CO 2 fluctuated between 0.1-0.4%. Lowering it to modern level (0.03%) occurred in the Oligocene and (after a certain increase in the Miocene) Pliocene. Atm. render creatures. influence on the evolution of the lithosphere. For example, b.ch. carbon dioxide, which entered Africa initially from the lithosphere, was then accumulated in carbonate rocks. Atm. and water vapor are the most important factors affecting the g. p. Ha throughout the entire history of the Earth atm. sediments play an important role in the process of hypergenesis. Of lesser importance is the activity of the wind ( cm. Weathering), carrying small destroyed urban settlements over long distances. Fluctuations in temperature and other atm significantly affect the destruction of the gp. factors.
A. Protects the Earth's surface from being destroyed. the action of falling stones (meteorites), b.ch. to-rykh burns out when entering its dense. Flora and rendered creatures. influence on A.'s development, strongly depend on atm. conditions. The ozone layer in A. delays b.h. ultraviolet radiation of the Sun, which would have a detrimental effect on living organisms. Oxygen A. is used in the process of respiration by animals and plants, carbon dioxide - in the process of plant nutrition. Atm. air is an important chemical. raw materials for industry: for example, atm. is a raw material for the production of ammonia, nitrogen to-you, etc. chem. connections; oxygen is used in decomp. industries x-va. All greater value acquires the development of wind energy, especially in regions where there are no other energies.
Building A. A. is characterized by a clearly expressed (Fig.), Determined by the features of the vertical distribution of temperature and the density of its constituent gases.

The course of the temperature is very complex, decreasing exponentially (80% of the total mass of A. is concentrated in the troposphere).
The transition region between A. and interplanetary space is its outermost part - the exosphere, consisting of rarefied hydrogen. At altitudes of 1-20 thousand km gravitational. the Earth's field is no longer capable of holding gas, and hydrogen molecules are scattered into space. space. The region of hydrogen dissipation creates the geocorona phenomenon. The first flights of the arts. satellites found that it is surrounded by several. shells of charged particles, gas-kinetic. pace-pa to-rykh reaches several. thousand degrees. These shells are called radiation belts. Charged particles - electrons and protons of solar origin - are captured by the Earth's magnetic field and cause in A. decomp. phenomena, eg. polar lights. Radiation The belts are part of the magnetosphere.
All parameters A. - temp-pa, pressure, density - are characterized by means. spatial and temporal variability (latitudinal, annual, seasonal, daily). Their dependence on solar flares was also found.
Composition A. Main A. components are nitrogen and oxygen, as well as carbon dioxide, and other gases (table).

The most important variable component of A. is water vapour. The change in its concentration varies widely: from 3% of the earth's surface at the equator to 0.2% in polar latitudes. Main its mass is concentrated in the troposphere, the content is determined by the ratio of the processes of evaporation, condensation and horizontal transfer. As a result of the condensation of water vapor, clouds form and atm falls out. precipitation (rain, hail, snow, poca, fog). Existing the variable component A. is carbon dioxide, the change in the content of which is associated with the vital activity of plants (photosynthesis processes) and solubility in the sea. water (gas exchange between the ocean and Africa). There is an increase in the content of carbon dioxide due to industrial pollution, which affects.
Radiation, heat and water balances A. Practically one. source of energy for all physical. processes developing in A., is solar radiation, transmitted by "windows of transparency" A. Ch. feature of radiation. mode A. - the so-called. Greenhouse effect- consists in the fact that it almost does not absorb radiation in the optical. range (b. h. radiation reaches the earth's surface and heats it) and the infrared (thermal) radiation of the Earth is not transmitted in the opposite direction, which significantly reduces the heat transfer of the planet and increases its rate. Part of the solar radiation incident on A. is absorbed (chiefly by water vapor, carbon dioxide, ozone and aerosols), the other part is scattered by gas molecules (which explains the blue color of the sky), dust particles and density fluctuations. Scattered radiation is summed up with direct sunlight and, having reached the Earth's surface, is partly reflected from it, partly absorbed. The proportion of reflected radiation depends on the reflection. the ability of the underlying surface (albedo). Radiation absorbed by the earth's surface is converted into infrared radiation, directed to A. In turn, A. is also a source of long-wave radiation directed to the Earth's surface (the so-called anti-radiation of A.) and into the world space (the so-called outgoing radiation). The difference between the short-wave radiation absorbed by the earth's surface and the effective radiation A. called. radiation balance.
The transformation of the radiation energy of the Sun after it has been absorbed by the earth's surface and A. constitutes the heat balance of the Earth. heat from A. to world space far exceeds the energy brought by absorbed radiation, but the deficit is made up for by its influx due to mechanical. heat exchange (turbulence) and the heat of condensation of water vapor. The value of the latter in A. is numerically equal to the cost of heat from the Earth's surface ( cm. water balance).
Air movement a. Due to the high mobility of atmospheric air, winds are observed at all altitudes in Africa. The direction of air movement depends on many factors. factors, but the main one is uneven heating A. in different p-ns. As a result, A. can be likened to a giant heat engine, which transforms the radiant energy coming from the Sun into kinetic energy. energy of moving air masses. Approx. It is estimated that the efficiency of this process is 2%, which corresponds to a power of 2.26 * 10 15 W. This energy is spent on the formation of large-scale eddies (cyclones and anticyclones) and the maintenance of a stable global wind system (monsoons and trade winds). Along with large-scale air currents in the lower. A. layers are observed numerous. local air circulation (breeze, bora, mountain-valley winds, etc.). In all air currents, pulsations are usually noted, corresponding to the movement of air vortices of medium and small sizes. Noticeable changes in meteorological conditions are achieved by such reclamation measures as irrigation, field-protective afforestation, swamps. p-new, creating arts. seas. These changes in the main limited to ground air.
In addition to directed impacts on weather and climate, human activity has an impact on the composition of A. Pollution of A. due to the action of energy, metallurgy, chemical objects. and horn. prom-sti occurs as a result of the release into the air Ch. arr. exhaust gases (90%), as well as dust and aerosols. The total mass of aerosols emitted annually into the air as a result of human activity, approx. 300 million tons. In connection with this, many countries are working to control air pollution. The rapid growth of the energy sector leads to additional heating A., to-poe is still noticeable only in large prom. centers, but in the future may lead to climate change in large territories. Pollution A. horn. enterprises depends on geol. the nature of the deposit being developed, the technology of extraction and processing of p. and. For example, the release of methane from coal seams during its development is approx. 90 million m 3 per year. During the conduct of blasting (for blasting of the settlement) during the year, approx. 8 million m 3 gases, of which b.ch. inert, not rendering harmful effects on environment. The intensity of gas evolution as a result of oxidizing. processes in dumps is relatively large. Abundant dust emission occurs during the processing of ores, as well as in the furnace. enterprises developing deposits open way with the use of blasting, especially in dry and wind-prone areas. Mineral particles pollute the air space for a short time. time, ch. arr. near enterprises, settling on the soil, the surface of water bodies, and other objects.
To prevent air pollution, gases are used: methane capture, air-foam and air-water curtains, exhaust gas cleaning, and an electric drive (instead of diesel) at the horn. and transp. equipment, isolation of mined-out spaces (backfilling), injection of water or antipyrogenic solutions into coal seams, etc. In ore processing processes, new technologies are introduced (including those with closed production cycles), gas treatment plants, smoke and gas removal to high layers A. and others. Reducing the emission of dust and aerosols in A. during the development of deposits is achieved by suppressing, binding and trapping dust in the process of drilling and blasting and loading and transport. works (irrigation with water, solutions, foams, application of emulsion or film coatings on dumps, sides and roads, etc.). When transporting ore, pipelines, containers, film and emulsion coatings are used, while processing - cleaning with filters, coating tailings with pebbles, organic. resins, reclamation, disposal of tailings. Literature: Matveev L. T., Kypc of General Meteorology, Atmospheric Physics, L., 1976; Xrgian A. Kh., Atmospheric Physics, 2nd ed., vol. 1-2, L., 1978; Budyko M.I., Climate in the past and in the future, L., 1980. M. I. Budyko.

Mountain Encyclopedia. - M.: Soviet Encyclopedia. Edited by E. A. Kozlovsky. 1984-1991 .

See what "Atmosphere" is in other dictionaries:

Atmosphere … Spelling Dictionary

atmosphere- uh. atmosphere f., n. lat. atmosphaera gr. 1. physical, meteor. Air shell of the earth, air. Sl. 18. In the atmosphere, or in the air that surrounds us .. and which we breathe. Karamzin 11 111. Scattering of light by the atmosphere. Astr. Lalanda 415.… … Historical Dictionary of Gallicisms of the Russian Language

Earth (from the Greek atmos steam and sphaira ball), the gaseous shell of the Earth, connected with it by gravity and taking part in its daily and annual rotation. Atmosphere. Scheme of the structure of the Earth's atmosphere (according to Ryabchikov). Weight A. approx. 5.15 10 8 kg.… … Ecological dictionary

- (Greek atmosphaira, from atmos pairs, and sphaira ball, sphere). 1) Gaseous shell, surrounding the earth or another planet. 2) the mental environment in which one moves. 3) a unit that measures the pressure experienced or produced ... ... Dictionary foreign words Russian language

The gaseous envelope that surrounds our planet Earth, known as the atmosphere, consists of five main layers. These layers originate on the surface of the planet, from sea level (sometimes below) and rise to outer space in the following sequence:

• Troposphere;
• Stratosphere;
• Mesosphere;
• Thermosphere;
• Exosphere.

Diagram of the main layers of the Earth's atmosphere

In between each of these main five layers are transitional zones called "pauses" where changes in air temperature, composition and density occur. Together with pauses, the Earth's atmosphere includes a total of 9 layers.

Troposphere: where the weather happens

Of all the layers of the atmosphere, the troposphere is the one with which we are most familiar (whether you realize it or not), since we live at its bottom - the surface of the planet. It envelops the surface of the Earth and extends upwards for several kilometers. The word troposphere means "change of the ball". A very fitting name, as this layer is where our day to day weather happens.

Starting from the surface of the planet, the troposphere rises to a height of 6 to 20 km. The lower third of the layer closest to us contains 50% of all atmospheric gases. It is the only part of the entire composition of the atmosphere that breathes. Due to the fact that the air is heated from below by the earth's surface, absorbing thermal energy Sun, with increasing altitude, the temperature and pressure of the troposphere decrease.

At the top is a thin layer called the tropopause, which is just a buffer between the troposphere and stratosphere.

Stratosphere: home of ozone

The stratosphere is the next layer of the atmosphere. It extends from 6-20 km to 50 km above the earth's surface. This is the layer in which most commercial airliners fly and balloons travel.

Here, the air does not flow up and down, but moves parallel to the surface in very fast air currents. As you ascend, the temperature increases, thanks to the abundance of natural ozone (O 3 ) - a by-product of solar radiation and oxygen, which has the ability to absorb harmful ultra-violet rays the sun (any increase in temperature with altitude in meteorology is known as an "inversion").

Since the stratosphere has more warm temperatures below and cooler above, convection (vertical movement of air masses) is rare in this part of the atmosphere. In fact, you can view a storm raging in the troposphere from the stratosphere, because the layer acts as a "cap" for convection, through which storm clouds do not penetrate.

The stratosphere is again followed by a buffer layer, this time called the stratopause.

Mesosphere: middle atmosphere

The mesosphere is located approximately 50-80 km from the Earth's surface. The upper mesosphere is the coldest natural place on Earth, where temperatures can drop below -143°C.

Thermosphere: upper atmosphere

The mesosphere and mesopause are followed by the thermosphere, located between 80 and 700 km above the surface of the planet, and containing less than 0.01% of the total air in the atmospheric envelope. Temperatures here reach up to + 2000 ° C, but due to the strong rarefaction of air and the lack of gas molecules for heat transfer, these high temperatures perceived as very cold.

Exosphere: the boundary of the atmosphere and space

At an altitude of about 700-10,000 km above the earth's surface is the exosphere - the outer edge of the atmosphere, bordering space. Here meteorological satellites revolve around the Earth.

How about the ionosphere?

The ionosphere is not a separate layer, and in fact this term is used to refer to the atmosphere at an altitude of 60 to 1000 km. It includes the uppermost parts of the mesosphere, the entire thermosphere and part of the exosphere. The ionosphere gets its name because in this part of the atmosphere, the Sun's radiation is ionized when it passes the Earth's magnetic fields at and . This phenomenon is observed from the earth as the northern lights.

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✪ Why wasn't the atmosphere pulled into the vacuum of space?

✪ Entry into the Earth's atmosphere of the spacecraft "Soyuz TMA-8"

✪ Atmosphere structure, meaning, study

✪ O. S. Ugolnikov "Upper atmosphere. Meeting of the Earth and space"

Subtitles

Atmosphere boundary

The atmosphere is considered to be that area around the Earth in which the gaseous medium rotates together with the Earth as a whole. The atmosphere passes into interplanetary space gradually, in the exosphere, starting at an altitude of 500-1000 km from the Earth's surface.

According to the definition proposed by the International Aviation Federation, the boundary between the atmosphere and space is drawn along the Karmana line, located at an altitude of about 100 km, above which air flights become completely impossible. NASA uses the 122 kilometers (400,000 ft) mark as the boundary of the atmosphere, where the shuttles switch from propulsion maneuvering to aerodynamic maneuvering.

Physical properties

In addition to the gases indicated in the table, the atmosphere contains Cl 2, SO 2, NH 3, CO, O 3, NO 2, hydrocarbons, HCl,, HBr, vapors, I 2, Br 2, as well as many other gases in minor quantities. In the troposphere there is constantly a large amount of suspended solid and liquid particles (aerosol). Radon (Rn) is the rarest gas in the Earth's atmosphere.

The structure of the atmosphere

boundary layer of the atmosphere

The lower layer of the troposphere (1-2 km thick), in which the state and properties of the Earth's surface directly affect the dynamics of the atmosphere.

Troposphere

Its upper limit is at an altitude of 8-10 km in polar, 10-12 km in temperate and 16-18 km in tropical latitudes; lower in winter than in summer.
The lower, main layer of the atmosphere contains more than 80% of the total mass of atmospheric air and about 90% of all water vapor present in the atmosphere. Turbulence and convection are strongly developed in the troposphere, clouds appear, cyclones and anticyclones develop. Temperature decreases with altitude with an average vertical gradient of 0.65°/100 meters.

tropopause

The transitional layer from the troposphere to the stratosphere, the layer of the atmosphere in which the decrease in temperature with height stops.

Stratosphere

The layer of the atmosphere located at an altitude of 11 to 50 km. A slight change in temperature in the 11-25 km layer (lower layer of the stratosphere) and its increase in the 25-40 km layer from −56.5 to +0.8 ° (upper stratosphere or inversion region) are typical. Having reached a value of about 273 K (almost 0 °C) at an altitude of about 40 km, the temperature remains constant up to an altitude of about 55 km. This region of constant temperature is called the stratopause and is the boundary between the stratosphere and the mesosphere.

Stratopause

The boundary layer of the atmosphere between the stratosphere and the mesosphere. There is a maximum in the vertical temperature distribution (about 0 °C).

Mesosphere

Thermosphere

The upper limit is about 800 km. The temperature rises to altitudes of 200-300 km, where it reaches values ​​of the order of 1500 K, after which it remains almost constant until high altitudes. Under the action of solar radiation and cosmic radiation, air is ionized (“polar lights”) - the main regions of the ionosphere lie inside the thermosphere. At altitudes above 300 km, atomic oxygen predominates. The upper limit of the thermosphere is largely determined by the current activity of the Sun. During periods of low activity - for example, in 2008-2009 - there is a noticeable decrease in the size of this layer.

Thermopause

The region of the atmosphere above the thermosphere. In this region, the absorption of solar radiation is insignificant and the temperature does not actually change with height.

Exosphere (sphere of scattering)

Up to a height of 100 km, the atmosphere is a homogeneous, well-mixed mixture of gases. In higher layers, the distribution of gases in height depends on their molecular weights, the concentration of heavier gases decreases faster with distance from the Earth's surface. Due to the decrease in gas density, the temperature drops from 0 °C in the stratosphere to −110 °C in the mesosphere. However, the kinetic energy of individual particles at altitudes of 200–250 km corresponds to a temperature of ~150 °C. Above 200 km, significant fluctuations in temperature and gas density are observed in time and space.

At an altitude of about 2000-3500 km, the exosphere gradually passes into the so-called near space vacuum, which is filled with rare particles of interplanetary gas, mainly hydrogen atoms. But this gas is only part of the interplanetary matter. The other part is composed of dust-like particles of cometary and meteoric origin. In addition to extremely rarefied dust-like particles, electromagnetic and corpuscular radiation of solar and galactic origin penetrates into this space.

Review

The troposphere accounts for about 80% of the mass of the atmosphere, the stratosphere accounts for about 20%; the mass of the mesosphere is no more than 0.3%, the thermosphere is less than 0.05% of the total mass of the atmosphere.

Based electrical properties emitted in the atmosphere the neutrosphere And ionosphere .

Depending on the composition of the gas in the atmosphere, they emit homosphere And heterosphere. heterosphere- this is an area where gravity affects the separation of gases, since their mixing at such a height is negligible. Hence follows the variable composition of the heterosphere. Below it lies a well-mixed, homogeneous part of the atmosphere, called the homosphere. The boundary between these layers is called turbopause, it lies at an altitude of about 120 km.

Other properties of the atmosphere and effects on the human body

Already at an altitude of 5 km above sea level, an untrained person develops oxygen starvation, and without adaptation, a person's performance is significantly reduced. This is where the physiological zone of the atmosphere ends. Human breathing becomes impossible at an altitude of 9 km, although up to about 115 km the atmosphere contains oxygen.

The atmosphere provides us with the oxygen we need to breathe. However, due to the drop in the total pressure of the atmosphere as you rise to a height, the partial pressure of oxygen also decreases accordingly.

History of the formation of the atmosphere

According to the most common theory, the Earth's atmosphere during the history of the latter moved into three different formulations. Initially, it consisted of light gases (hydrogen and helium) captured from interplanetary space. This so-called primary atmosphere. At the next stage, active volcanic activity led to the saturation of the atmosphere with gases other than hydrogen (carbon dioxide, ammonia, water vapor). This is how secondary atmosphere. This atmosphere was restorative. Further, the process of formation of the atmosphere was determined by the following factors:

• leakage of light gases (hydrogen and helium) into interplanetary space;
• chemical reactions occurring in the atmosphere under the influence of ultraviolet radiation, lightning discharges and some other factors.

Gradually, these factors led to the formation tertiary atmosphere, characterized by a much lower content of hydrogen and a much higher content of nitrogen and carbon dioxide (formed as a result of chemical reactions from ammonia and hydrocarbons).

Nitrogen

Education a large number nitrogen N 2 is due to the oxidation of the ammonia-hydrogen atmosphere by molecular oxygen O 2, which began to come from the surface of the planet as a result of photosynthesis, starting from 3 billion years ago. Nitrogen N 2 is also released into the atmosphere as a result of the denitrification of nitrates and other nitrogen-containing compounds. Nitrogen is oxidized by ozone to NO in the upper atmosphere.

Nitrogen N 2 enters into reactions only under specific conditions (for example, during a lightning discharge). Oxidation of molecular nitrogen by ozone during electrical discharges is used in small quantities in the industrial production of nitrogen fertilizers. It can be oxidized with low energy consumption and converted into a biologically active form by cyanobacteria (blue-green algae) and nodule bacteria, forming a rhizobial symbiosis with legumes, which can be effective green manure - plants that do not deplete, but enrich the soil with natural fertilizers.

Oxygen

The composition of the atmosphere began to change radically with the advent of living organisms on Earth, as a result of photosynthesis, accompanied by the release of oxygen and the absorption of carbon dioxide. Initially, oxygen was spent on the oxidation of reduced compounds - ammonia, hydrocarbons, the ferrous form of iron contained in the oceans and others. At the end this stage the oxygen content in the atmosphere began to rise. Gradually, a modern atmosphere with oxidizing properties formed. Since this caused serious drastic changes many processes occurring in the atmosphere, lithosphere and biosphere, this event was called the Oxygen Catastrophe.

noble gases

Air pollution

Recently, man has begun to influence the evolution of the atmosphere. result human activity there was a constant increase in the content of carbon dioxide in the atmosphere due to the combustion of hydrocarbon fuels accumulated in previous geological epochs. Huge amounts of CO 2 are consumed during photosynthesis and absorbed by the world's oceans. This gas enters the atmosphere due to the decomposition of carbonate rocks and organic substances of plant and animal origin, as well as due to volcanism and production activities person. Over the past 100 years, the content of CO 2 in the atmosphere has increased by 10%, with the main part (360 billion tons) coming from fuel combustion. If the growth rate of fuel combustion continues, then in the next 200-300 years the amount of CO 2 in the atmosphere will double and may lead to global climate changes.

Fuel combustion is the main source of polluting gases (СО,, SO 2). Sulfur dioxide is oxidized by atmospheric oxygen to SO 3, and nitric oxide to NO 2 in the upper atmosphere, which in turn interact with water vapor, and the resulting sulfuric acid H 2 SO 4 and nitric acid HNO 3 fall on the Earth's surface in the form so-called acid rain. Usage