The Earth's atmosphere is the gaseous envelope of the planet. The lower boundary of the atmosphere passes near the earth's surface (the hydrosphere and the earth's crust), and the upper boundary is the area of contact outer space (122 km). The atmosphere contains many different elements. The main ones are: 78% nitrogen, 20% oxygen, 1% argon, carbon dioxide, neon gallium, hydrogen, etc. Interesting facts can be viewed at the end of the article or by clicking on.
The atmosphere has distinct layers of air. Air layers differ in temperature, gas difference and their density and. It should be noted that the layers of the stratosphere and troposphere protect the Earth from solar radiation. In the higher layers, a living organism can receive a lethal dose of the ultraviolet solar spectrum. To quickly jump to the desired layer of the atmosphere, click on the corresponding layer:
Troposphere and tropopause
Troposphere - temperature, pressure, altitude
The upper limit is kept at around 8 - 10 km approximately. In temperate latitudes 16 - 18 km, and in polar 10 - 12 km. Troposphere It is the lower main layer of the atmosphere. This layer contains more than 80% of the total mass of atmospheric air and close to 90% of the total water vapor. It is in the troposphere that convection and turbulence arise, cyclones form, and occur. Temperature decreases with height. Gradient: 0.65°/100 m. The heated earth and water heat up the enclosing air. The heated air rises, cools and forms clouds. The temperature in the upper boundaries of the layer can reach -50/70 °C.
It is in this layer that changes in climatic weather conditions occur. The lower limit of the troposphere is called surface since it has a lot of volatile microorganisms and dust. Wind speed increases with height in this layer.
tropopause
This is the transitional layer of the troposphere to the stratosphere. Here, the dependence of the decrease in temperature with an increase in altitude ceases. The tropopause is the minimum height where the vertical temperature gradient drops to 0.2°C/100 m. The height of the tropopause depends on strong climatic events such as cyclones. The height of the tropopause decreases above cyclones and increases above anticyclones.
Stratosphere and Stratopause
The height of the stratosphere layer is approximately from 11 to 50 km. There is a slight change in temperature at an altitude of 11-25 km. At an altitude of 25–40 km, inversion temperature, from 56.5 rises to 0.8°C. From 40 km to 55 km the temperature stays at around 0°C. This area is called - stratopause.
In the Stratosphere, the effect of solar radiation on gas molecules is observed, they dissociate into atoms. There is almost no water vapor in this layer. Modern supersonic commercial aircraft fly at altitudes up to 20 km due to stable flight conditions. High-altitude weather balloons rise to a height of 40 km. There are steady air currents here, their speed reaches 300 km/h. Also in this layer is concentrated ozone, a layer that absorbs ultraviolet rays.
Mesosphere and Mesopause - composition, reactions, temperature
The mesosphere layer begins at about 50 km and ends at around 80-90 km. Temperatures decrease with elevation by about 0.25-0.3°C/100 m. Radiant heat exchange is the main energy effect here. Complex photochemical processes involving free radicals (has 1 or 2 unpaired electrons) since they implement glow atmosphere.
Almost all meteors burn up in the mesosphere. Scientists have named this area Ignorosphere. This zone is difficult to explore, as aerodynamic aviation here is very poor due to the air density, which is 1000 times less than on Earth. And for launching artificial satellites, the density is still very high. Research is carried out with the help of meteorological rockets, but this is a perversion. mesopause transitional layer between mesosphere and thermosphere. Has a minimum temperature of -90°C.
Karman Line
Pocket line called the boundary between the Earth's atmosphere and outer space. According to the International Aviation Federation (FAI), the height of this border is 100 km. This definition was given in honor of the American scientist Theodor von Karman. He determined that at about this height the density of the atmosphere is so low that aerodynamic aviation becomes impossible here, since the speed of the aircraft must be greater first space velocity. At such a height, the concept of a sound barrier loses its meaning. Here you can control the aircraft only due to reactive forces.
Thermosphere and Thermopause
The upper boundary of this layer is about 800 km. The temperature rises up to about 300 km, where it reaches about 1500 K. Above, the temperature remains unchanged. In this layer there is Polar Lights- occurs as a result of the effect of solar radiation on the air. This process is also called the ionization of atmospheric oxygen.
Due to the low rarefaction of the air, flights above the Karman line are possible only along ballistic trajectories. All manned orbital flights (except flights to the Moon) take place in this layer of the atmosphere.
Exosphere - Density, Temperature, Height
The height of the exosphere is above 700 km. Here the gas is very rarefied, and the process takes place dissipation— leakage of particles into interplanetary space. The speed of such particles can reach 11.2 km/sec. The growth of solar activity leads to the expansion of the thickness of this layer.
- The gas shell does not fly away into space due to gravity. Air is made up of particles that have their own mass. From the law of gravitation, it can be concluded that every object with mass is attracted to the Earth.
- Buys-Ballot's law states that if you are in the Northern Hemisphere and stand with your back to the wind, then there will be a high pressure zone on the right, and low pressure on the left. In the Southern Hemisphere, it will be the other way around.
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, which absorbs the thermal energy of the Sun, the temperature and pressure of the troposphere decrease with increasing altitude.
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. Temperatures increase as you ascend, thanks to an abundance of naturally occurring ozone (O3), a by-product of solar radiation, and oxygen, which has the ability to absorb the sun's harmful ultraviolet rays (any rise in temperature with altitude is known in meteorology as an "inversion") .
Because the stratosphere has warmer temperatures at the bottom and cooler temperatures at the top, convection (vertical movements 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 shell. Temperatures here reach up to +2000° C, but due to the strong rarefaction of the air and the lack of gas molecules to transfer heat, these high temperatures are 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.
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. It 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 m
For "normal conditions" at the Earth's surface are taken: density 1.2 kg/m3, barometric pressure 101.35 kPa, temperature plus 20 °C and relative humidity 50%. These conditional indicators have a purely engineering value.
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 characteristic. 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
mesopause
Transitional layer between mesosphere and thermosphere. There is a minimum in the vertical temperature distribution (about -90°C).
Karman Line
Altitude above sea level, which is conventionally accepted as the boundary between the Earth's atmosphere and space.
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 up to high altitudes. Under the influence of ultraviolet and x-ray 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.
Exosphere (scattering sphere)
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 masses, 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 ~1500°C. Above 200 km, significant fluctuations in temperature and gas density are observed in time and space.
At an altitude of about 2000-3000 km, the exosphere gradually passes into the so-called near space vacuum, which is filled with highly rarefied 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.
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 on the electrical properties in the atmosphere, the neutrosphere and ionosphere are distinguished. It is currently believed that the atmosphere extends to an altitude of 2000-3000 km.
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.
Physical properties
The thickness of the atmosphere is approximately 2000 - 3000 km from the Earth's surface. The total mass of air - (5.1-5.3)? 10 18 kg. The molar mass of clean dry air is 28.966. Pressure at 0 °C at sea level 101.325 kPa; critical temperature ?140.7 °C; critical pressure 3.7 MPa; C p 1.0048?10? J / (kg K) (at 0 °C), C v 0.7159 10? J/(kg K) (at 0 °C). Solubility of air in water at 0°С - 0.036%, at 25°С - 0.22%.
Physiological and other properties of the atmosphere
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 15 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.
The human lungs constantly contain about 3 liters of alveolar air. The partial pressure of oxygen in the alveolar air at normal atmospheric pressure is 110 mm Hg. Art., pressure of carbon dioxide - 40 mm Hg. Art., and water vapor - 47 mm Hg. Art. With increasing altitude, the oxygen pressure drops, and the total pressure of water vapor and carbon dioxide in the lungs remains almost constant - about 87 mm Hg. Art. The flow of oxygen into the lungs will completely stop when the pressure of the surrounding air becomes equal to this value.
At an altitude of about 19-20 km, the atmospheric pressure drops to 47 mm Hg. Art. Therefore, at this height, water and interstitial fluid begin to boil in the human body. Outside the pressurized cabin at these altitudes, death occurs almost instantly. Thus, from the point of view of human physiology, "space" begins already at an altitude of 15-19 km.
Dense layers of air - the troposphere and stratosphere - protect us from the damaging effects of radiation. With sufficient rarefaction of air, at altitudes of more than 36 km, ionizing radiation, primary cosmic rays, has an intense effect on the body; at altitudes of more than 40 km, the ultraviolet part of the solar spectrum, which is dangerous for humans, operates.
As we rise to an ever greater height above the Earth's surface, gradually weaken, and then completely disappear, such phenomena that are familiar to us observed in the lower layers of the atmosphere, such as the propagation of sound, the occurrence of aerodynamic lift and resistance, heat transfer by convection, etc.
In rarefied layers of air, the propagation of sound is impossible. Up to altitudes of 60-90 km, it is still possible to use air resistance and lift for controlled aerodynamic flight. But starting from altitudes of 100-130 km, the concepts of the M number and the sound barrier familiar to every pilot lose their meaning, there passes the conditional Karman Line, beyond which the sphere of purely ballistic flight begins, which can only be controlled using reactive forces.
At altitudes above 100 km, the atmosphere is also deprived of another remarkable property - the ability to absorb, conduct and transfer thermal energy by convection (i.e., by means of air mixing). This means that various elements of equipment, equipment of the orbital space station will not be able to be cooled from the outside in the way it is usually done on an airplane - with the help of air jets and air radiators. At such a height, as in space in general, the only way to transfer heat is thermal radiation.
Composition of the atmosphere
The Earth's atmosphere consists mainly of gases and various impurities (dust, water drops, ice crystals, sea salts, combustion products).
The concentration of gases that make up the atmosphere is almost constant, with the exception of water (H 2 O) and carbon dioxide (CO 2).
| Gas | Content by volume, % |
Content by weight, % |
|---|---|---|
| Nitrogen | 78,084 | 75,50 |
| Oxygen | 20,946 | 23,10 |
| Argon | 0,932 | 1,286 |
| Water | 0,5-4 | - |
| Carbon dioxide | 0,032 | 0,046 |
| Neon | 1.818×10 −3 | 1.3×10 −3 |
| Helium | 4.6×10 −4 | 7.2×10 −5 |
| Methane | 1.7×10 −4 | - |
| Krypton | 1.14×10 −4 | 2.9×10 −4 |
| Hydrogen | 5×10 −5 | 7.6×10 −5 |
| Xenon | 8.7×10 −6 | - |
| Nitrous oxide | 5×10 −5 | 7.7×10 −5 |
In addition to the gases indicated in the table, the atmosphere contains SO 2, NH 3, CO, ozone, hydrocarbons, HCl, vapors, I 2, as well as many other gases in small quantities. In the troposphere there is constantly a large amount of suspended solid and liquid particles (aerosol).
History of the formation of the atmosphere
According to the most common theory, the Earth's atmosphere has been in four different compositions over time. Initially, it consisted of light gases (hydrogen and helium) captured from interplanetary space. This so-called primary atmosphere(about four billion years ago). 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(about three billion years before our days). 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
The formation of a large amount of N 2 is due to the oxidation of the ammonia-hydrogen atmosphere by molecular O 2, which began to come from the surface of the planet as a result of photosynthesis, starting from 3 billion years ago. 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 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 that form rhizobial symbiosis with legumes, the so-called. green manure.
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, etc. At the end of this stage, the oxygen content in the atmosphere began to grow. Gradually, a modern atmosphere with oxidizing properties formed. Since this caused serious and abrupt changes in many processes occurring in the atmosphere, lithosphere and biosphere, this event was called the Oxygen Catastrophe.
Carbon dioxide
The content of CO 2 in the atmosphere depends on volcanic activity and chemical processes in the earth's shells, but most of all - on the intensity of biosynthesis and decomposition of organic matter in the Earth's biosphere. Almost the entire current biomass of the planet (about 2.4 × 10 12 tons) is formed due to carbon dioxide, nitrogen and water vapor contained in the atmospheric air. Buried in the ocean , swamps and forests , organic matter turns into coal , oil and natural gas . (see Geochemical carbon cycle)
noble gases
Air pollution
Recently, man has begun to influence the evolution of the atmosphere. The result of his activities was a constant significant 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 human production activities. 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 50 - 60 years the amount of CO 2 in the atmosphere will double and may lead to global climate change.
Fuel combustion is the main source of polluting gases (СО,, SO 2). Sulfur dioxide is oxidized by atmospheric oxygen to SO 3 in the upper atmosphere, which in turn interacts with water vapor and ammonia, and the resulting sulfuric acid (H 2 SO 4) and ammonium sulfate ((NH 4) 2 SO 4) return to the surface of the Earth in the form of a so-called. acid rain. The use of internal combustion engines leads to significant air pollution with nitrogen oxides, hydrocarbons and lead compounds (tetraethyl lead Pb (CH 3 CH 2) 4)).
Aerosol pollution of the atmosphere is caused both by natural causes (volcanic eruption, dust storms, entrainment of sea water droplets and plant pollen, etc.) and by human economic activity (mining of ores and building materials, fuel combustion, cement production, etc.). Intense large-scale removal of solid particles into the atmosphere is one of the possible causes of climate change on the planet.
Literature
- V. V. Parin, F. P. Kosmolinsky, B. A. Dushkov "Space biology and medicine" (2nd edition, revised and enlarged), M.: "Prosveshchenie", 1975, 223 pages.
- N. V. Gusakova "Environmental Chemistry", Rostov-on-Don: Phoenix, 2004, 192 s ISBN 5-222-05386-5
- Sokolov V. A. Geochemistry of natural gases, M., 1971;
- McEwen M., Phillips L.. Atmospheric Chemistry, M., 1978;
- Wark K., Warner S., Air pollution. Sources and control, trans. from English, M.. 1980;
- Monitoring of background pollution of natural environments. in. 1, L., 1982.
see also
Links
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Earth's atmosphere |
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 middle - 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 of mercury, 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 the early periods of the Phanerozoic, the 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 increased again, reaching a 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%. Downgrading 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. The development of wind energy is becoming increasingly important, especially in regions where other energies are absent.
Building A. A. is characterized by a clearly expressed (Fig.), Determined by the peculiarities 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). The radiation absorbed by the earth's surface is processed 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 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 areas. 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 harmful to the 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 in an 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 a diesel one) 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 .
Synonyms: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 couples, and sphaira ball, sphere). 1) A gaseous shell that surrounds the earth or another planet. 2) the mental environment in which one moves. 3) a unit that measures the pressure experienced or produced ... ... Dictionary of foreign words of the Russian language
The atmosphere is the gaseous shell of our planet that rotates with the Earth. The gas in the atmosphere is called air. The atmosphere is in contact with the hydrosphere and partially covers the lithosphere. But it is difficult to determine the upper bounds. Conventionally, it is assumed that the atmosphere extends upwards for about three thousand kilometers. There it flows smoothly into the airless space.
The chemical composition of the Earth's atmosphere
The formation of the chemical composition of the atmosphere began about four billion years ago. Initially, the atmosphere consisted only of light gases - helium and hydrogen. According to scientists, the initial prerequisites for the creation of a gas shell around the Earth were volcanic eruptions, which, together with lava, emitted a huge amount of gases. Subsequently, gas exchange began with water spaces, with living organisms, with the products of their activity. The composition of the air gradually changed and in its present form was fixed several million years ago.
The main components of the atmosphere are nitrogen (about 79%) and oxygen (20%). The remaining percentage (1%) is accounted for by the following gases: argon, neon, helium, methane, carbon dioxide, hydrogen, krypton, xenon, ozone, ammonia, sulfur dioxide and nitrogen, nitrous oxide and carbon monoxide included in this one percent.
In addition, the air contains water vapor and particulate matter (plant pollen, dust, salt crystals, aerosol impurities).
Recently, scientists have noted not a qualitative, but a quantitative change in some air ingredients. And the reason for this is the person and his activity. Only in the last 100 years, the content of carbon dioxide has increased significantly! This is fraught with many problems, the most global of which is climate change.
Formation of weather and climate
The atmosphere plays a vital role in shaping the climate and weather on Earth. A lot depends on the amount of sunlight, on the nature of the underlying surface and atmospheric circulation.
Let's look at the factors in order.
1. The atmosphere transmits the heat of the sun's rays and absorbs harmful radiation. The ancient Greeks knew that the rays of the Sun fall on different parts of the Earth at different angles. The very word "climate" in translation from ancient Greek means "slope". So, at the equator, the sun's rays fall almost vertically, because it is very hot here. The closer to the poles, the greater the angle of inclination. And the temperature is dropping.
2. Due to the uneven heating of the Earth, air currents are formed in the atmosphere. They are classified according to their size. The smallest (tens and hundreds of meters) are local winds. This is followed by monsoons and trade winds, cyclones and anticyclones, planetary frontal zones.
All these air masses are constantly moving. Some of them are quite static. For example, the trade winds that blow from the subtropics towards the equator. The movement of others is largely dependent on atmospheric pressure.
3. Atmospheric pressure is another factor influencing climate formation. This is the air pressure on the earth's surface. As you know, air masses move from an area with high atmospheric pressure towards an area where this pressure is lower.
There are 7 zones in total. The equator is a low pressure zone. Further, on both sides of the equator up to the thirtieth latitudes - an area of high pressure. From 30° to 60° - again low pressure. And from 60° to the poles - a zone of high pressure. Air masses circulate between these zones. Those that go from the sea to land bring rain and bad weather, and those that blow from the continents bring clear and dry weather. In places where air currents collide, atmospheric front zones are formed, which are characterized by precipitation and inclement, windy weather.
Scientists have proven that even a person's well-being depends on atmospheric pressure. According to international standards, normal atmospheric pressure is 760 mm Hg. column at 0°C. This figure is calculated for those areas of land that are almost flush with sea level. The pressure decreases with altitude. Therefore, for example, for St. Petersburg 760 mm Hg. - is the norm. But for Moscow, which is located higher, the normal pressure is 748 mm Hg.
The pressure changes not only vertically, but also horizontally. This is especially felt during the passage of cyclones.
The structure of the atmosphere
The atmosphere is like a layer cake. And each layer has its own characteristics.
. Troposphere is the layer closest to the Earth. The "thickness" of this layer changes as you move away from the equator. Above the equator, the layer extends upwards for 16-18 km, in temperate zones - for 10-12 km, at the poles - for 8-10 km.
It is here that 80% of the total mass of air and 90% of water vapor are contained. Clouds form here, cyclones and anticyclones arise. The air temperature depends on the altitude of the area. On average, it drops by 0.65°C for every 100 meters.
. tropopause- transitional layer of the atmosphere. Its height is from several hundred meters to 1-2 km. The air temperature in summer is higher than in winter. So, for example, over the poles in winter -65 ° C. And over the equator at any time of the year it is -70 ° C.
. Stratosphere- this is a layer, the upper boundary of which runs at an altitude of 50-55 kilometers. Turbulence is low here, water vapor content in the air is negligible. But a lot of ozone. Its maximum concentration is at an altitude of 20-25 km. In the stratosphere, the air temperature begins to rise and reaches +0.8 ° C. This is due to the fact that the ozone layer interacts with ultraviolet radiation.
. Stratopause- a low intermediate layer between the stratosphere and the mesosphere following it.
. Mesosphere- the upper boundary of this layer is 80-85 kilometers. Here complex photochemical processes involving free radicals take place. It is they who provide that gentle blue glow of our planet, which is seen from space.
Most comets and meteorites burn up in the mesosphere.
. mesopause- the next intermediate layer, the air temperature in which is at least -90 °.
. Thermosphere- the lower boundary begins at an altitude of 80 - 90 km, and the upper boundary of the layer passes approximately at the mark of 800 km. The air temperature is rising. It can vary from +500° C to +1000° C. During the day, temperature fluctuations amount to hundreds of degrees! But the air here is so rarefied that the understanding of the term "temperature" as we imagine it is not appropriate here.
. Ionosphere- unites mesosphere, mesopause and thermosphere. The air here consists mainly of oxygen and nitrogen molecules, as well as quasi-neutral plasma. The sun's rays, falling into the ionosphere, strongly ionize air molecules. In the lower layer (up to 90 km), the degree of ionization is low. The higher, the more ionization. So, at an altitude of 100-110 km, electrons are concentrated. This contributes to the reflection of short and medium radio waves.
The most important layer of the ionosphere is the upper one, which is located at an altitude of 150-400 km. Its peculiarity is that it reflects radio waves, and this contributes to the transmission of radio signals over long distances.
It is in the ionosphere that such a phenomenon as aurora occurs.
. Exosphere- consists of oxygen, helium and hydrogen atoms. The gas in this layer is very rarefied, and often hydrogen atoms escape into outer space. Therefore, this layer is called the "scattering zone".
The first scientist who suggested that our atmosphere has weight was the Italian E. Torricelli. Ostap Bender, for example, in the novel "The Golden Calf" lamented that each person was pressed by an air column weighing 14 kg! But the great strategist was a little mistaken. An adult person experiences pressure of 13-15 tons! But we do not feel this heaviness, because atmospheric pressure is balanced by the internal pressure of a person. The weight of our atmosphere is 5,300,000,000,000,000 tons. The figure is colossal, although it is only a millionth of the weight of our planet.