Formation of the earth and its atmosphere. Information and facts about the atmosphere. Atmosphere of the Earth. As a result of acid rain, forests in Western Europe, the Baltic States, Karelia, the Urals, Siberia and Canada are at risk of destruction.

Formation of the atmosphere. Today, the Earth's atmosphere is a mixture of gases - 78% nitrogen, 21% oxygen and small amounts of other gases, such as carbon dioxide. But when the planet first appeared, there was no oxygen in the atmosphere - it consisted of gases that originally existed in the solar system.

Earth arose when small rocky bodies made of dust and gas from the solar nebula, known as planetoids, collided with each other and gradually took the shape of a planet. As it grew, the gases contained in the planetoids burst out and enveloped the globe. After some time, the first plants began to release oxygen, and the primordial atmosphere developed into the current dense air envelope.

Origin of the atmosphere

A rain of small planetoids fell on the nascent Earth 4.6 billion years ago. Gases from the solar nebula trapped inside the planet burst out during the collision and formed the Earth's primitive atmosphere, consisting of nitrogen, carbon dioxide and water vapor.
The heat released during the formation of the planet is retained by a layer of dense clouds in the primordial atmosphere. "Greenhouse gases" such as carbon dioxide and water vapor stop the radiation of heat into space. The surface of the Earth is flooded with a seething sea of molten magma.
When planetoid collisions became less frequent, the Earth began to cool and oceans appeared. Water vapor condenses from thick clouds, and rain, lasting for several eons, gradually floods the lowlands. Thus the first seas appear.
The air is purified as water vapor condenses to form oceans. Over time, carbon dioxide dissolves in them, and the atmosphere is now dominated by nitrogen. Due to the lack of oxygen, the protective ozone layer does not form, and ultraviolet rays from the sun reach the earth's surface without hindrance.
Life appears in ancient oceans within the first billion years. The simplest blue-green algae are protected from ultraviolet radiation by seawater. They use sunlight and carbon dioxide to produce energy, releasing oxygen as a byproduct, which gradually begins to accumulate in the atmosphere.
Billions of years later, an oxygen-rich atmosphere forms. Photochemical reactions in the upper atmosphere create a thin layer of ozone that scatters harmful ultraviolet light. Life can now emerge from the oceans onto land, where evolution produces many complex organisms.

Billions of years ago, a thick layer of primitive algae began releasing oxygen into the atmosphere. They survive to this day in the form of fossils called stromatolites.

Volcanic origin

1. Ancient, airless Earth. 2. Eruption of gases.

According to this theory, volcanoes were actively erupting on the surface of the young planet Earth. The early atmosphere likely formed when gases trapped in the planet's silicon shell escaped through volcanoes.

STRUCTURE OF THE BIOSPHERE

Biosphere- the geological shell of the Earth, populated by living organisms, under their influence and occupied by the products of their vital activity; “film of life”; global ecosystem of the Earth.

The term " biosphere"was introduced in biology by Jean-Baptiste Lamarck (Fig. 4.18) at the beginning of the 19th century, and in geology it was proposed by the Austrian geologist Eduard Suess (Fig. 4.19) in 1875.

A holistic doctrine of the biosphere was created by the Russian biogeochemist and philosopher V.I. Vernadsky. For the first time, he assigned living organisms the role of the most important transformative force on planet Earth, taking into account their activities not only at the present time, but also in the past.

The biosphere is located at the intersection of the upper part of the lithosphere, the lower part of the atmosphere and occupies the entire hydrosphere (Fig. 4.1).

Fig.4.1 Biosphere

Boundaries of the biosphere

Upper limit in the atmosphere: 15÷20 km. It is determined by the ozone layer, which blocks short-wave UV radiation, which is harmful to living organisms.
Lower boundary in the lithosphere: 3.5÷7.5 km. It is determined by the temperature of transition of water into steam and the temperature of denaturation of proteins, but generally the distribution of living organisms is limited to a depth of several meters.
Lower limit in the hydrosphere: 10÷11 km. It is determined by the bottom of the World Ocean, including bottom sediments.

The biosphere is composed of the following types of substances:

Living matter- the entire set of bodies of living organisms inhabiting the Earth is physical and chemically united, regardless of their systematic affiliation. The mass of living matter is relatively small and is estimated at 2.4-3.6·10 12 tons (dry weight) and is less than 10 -6 the mass of other shells of the Earth. But this is “one of the most powerful geochemical forces on our planet,” since living matter not only inhabits the biosphere, but transforms the appearance of the Earth. Living matter is distributed very unevenly within the biosphere.
Nutrient- a substance created and processed by living matter. During organic evolution, living organisms passed through their organs, tissues, cells, and blood a thousand times through the entire atmosphere, the entire volume of the world's oceans, and a huge mass of mineral substances. This geological role of living matter can be imagined from deposits of coal, oil, carbonate rocks, etc.
Inert substance- in the formation of which life does not participate; solid, liquid and gaseous.
Bioinert substance, which is created simultaneously by living organisms and inert processes, representing dynamically equilibrium systems of both. These are soil, silt, weathering crust, etc. Organisms play a leading role in them.
Substance undergoing radioactive decay.
Scattered atoms, continuously created from all kinds of terrestrial matter under the influence of cosmic radiation.
Substance of cosmic origin.

Structure of the earth

There is mostly speculative information about the structure, composition and properties of the “solid” Earth, since only the uppermost part of the earth’s crust is accessible to direct observation. The most reliable of them are seismic methods, based on the study of the paths and speed of propagation of elastic vibrations (seismic waves) in the Earth. With their help, it was possible to establish the division of the “solid” Earth into separate spheres and get an idea of the internal structure of the Earth.” It turns out that the generally accepted idea of the deep structure of the globe is an assumption, because it was not created based on direct factual data. In geography textbooks, the earth's crust, mantle and core are reported as real-life objects without a shadow of doubt about their possible fictitiousness. The term “earth’s crust” appeared in the middle of the 19th century, when the hypothesis of the formation of the Earth from a hot gas ball, currently called the Kant-Laplace hypothesis, gained recognition in natural science. The thickness of the earth's crust was assumed to be 10 miles (16 km). Below is the primordial molten material preserved from the formation of our planet.

In 1909 On the Balkan Peninsula, near the city of Zagreb, a strong earthquake occurred. Croatian geophysicist Andrija Mohorovicic, studying a seismogram recorded at the time of this event, noticed that at a depth of about 30 km the wave speed increases significantly. This observation was confirmed by other seismologists. This means that there is a certain section limiting the earth’s crust from below. To designate it, a special term was introduced - the Mohorovicic surface (or Moho section) (Fig. 4.2).

Fig. 4.2 Mantle, asthenosphere, Mohorovicic surface

The Earth is encased in a hard outer shell, or lithosphere, consisting of the crust and a solid upper layer of the mantle. The lithosphere is split into huge blocks, or plates. Under the pressure of powerful underground forces, these plates are constantly moving (Fig. 4.3). In some places, their movement leads to the emergence of mountain ranges, in others the edges of the plates are pulled into deep depressions. This phenomenon is called underthrust, or subduction. As the plates shift, they either connect or split, and the zones of their junctions are called boundaries. It is at these weakest points in the earth’s crust that volcanoes most often arise.

Fig. 4.3 Earth Plates

Under the crust at depths from 30-50 to 2900 km is the Earth's mantle. It consists mainly of rocks rich in magnesium and iron. The mantle occupies up to 82% of the planet's volume and is divided into upper and lower. The first lies below the Moho surface to a depth of 670 km. A rapid drop in pressure in the upper part of the mantle and high temperature lead to the melting of its substance. At a depth of 400 km under continents and 10-150 km under oceans, i.e. in the upper mantle, a layer was discovered where seismic waves travel relatively slowly. This layer was called the asthenosphere (from the Greek “asthenes” - weak). Here the proportion of melt is 1-3%, more plastic than the rest of the mantle. The asthenosphere serves as a “lubricant” along which rigid lithospheric plates move. Compared to the rocks that make up the earth's crust, the rocks of the mantle are distinguished by their high density and the speed of propagation of seismic waves in them is noticeably higher. In the very “basement” of the lower mantle - at a depth of 1000 km and up to the surface of the core - the density gradually increases. What the lower mantle consists of remains a mystery.

Fig.4.4 Estimated structure of the Earth

It is assumed that the surface of the core consists of a substance with the properties of a liquid. The core boundary is located at a depth of 2900 km. But the inner region, starting from a depth of 5100 km, should behave like a solid body. This must be due to very high blood pressure. Even at the upper boundary of the core, the theoretically calculated pressure is about 1.3 million atm. and in the center it reaches 3 million atm. The temperature here can exceed 10,000 o C. However, how valid these assumptions are can only be guessed at (Fig. 4.4). The very first test by drilling of the structure of the earth's crust of the continental type from the granite layer and below it the basalt layer gave different results. We are talking about the results of drilling the Kola superdeep well (Fig. 4.5). It was founded in the north of the Kola Peninsula for purely scientific purposes to open the supposedly predicted basalt layer at a depth of 7 km. The rocks there have a velocity of longitudinal seismic waves of 7.0-7.5 km/s. According to these data, the basalt layer is identified everywhere. This location was chosen because, according to geophysical data, the basalt layer within the USSR is located here closest to the surface of the lithosphere. Above that lie rocks with longitudinal wave velocities of 6.0-6.5 km/s – a granite layer.

Fig. 4.5 Kola superdeep well

The real section opened by the Kola superdeep well turned out to be completely different. To a depth of 6842 m, sandstones and tuffs of basaltic composition with bodies of dolerites (cryptocrystalline basalts) are common, and below - gneisses, granite-gneisses, and less commonly - amphibolites. The most important thing in the results of drilling the Kola superdeep well, the only one drilled on Earth deeper than 12 km, is that they not only refuted the generally accepted idea of the structure of the upper part of the lithosphere, but that before they were obtained it was generally impossible to talk about the material structure of these depths globe. However, neither school nor university textbooks on geography and geology report the results of drilling the Kola superdeep well, and the presentation of the Lithosphere section begins with what is said about the core, mantle and crust, which on the continents is composed of a granite layer, and below - a basalt layer.

Earth's atmosphere

Atmosphere Earth - the air shell of the Earth, consisting mainly of gases and various impurities (dust, water drops, ice crystals, sea salts, combustion products), the amount of which is not constant. The atmosphere up to an altitude of 500 km consists of the troposphere, stratosphere, mesosphere, ionosphere (thermosphere), exosphere (Fig. 4.6)

Fig. 4.6 The structure of the atmosphere up to an altitude of 500 km

Troposphere- the lower, most studied layer of the atmosphere, 8-10 km high in the polar regions, up to 10-12 km in temperate latitudes, and 16-18 km at the equator. The troposphere contains approximately 80-90% of the total mass of the atmosphere and almost all water vapor. When rising every 100 m, the temperature in the troposphere decreases by an average of 0.65° and reaches 220 K (−53°C) in the upper part. This upper layer of the troposphere is called the tropopause.

Stratosphere- a layer of the atmosphere located at an altitude of 11 to 50 km. Characterized by a slight change in temperature in the 11-25 km layer (lower layer of the stratosphere) and an increase in temperature in the 25-40 km layer from −56.5 to 0.8 ° C (upper layer of the stratosphere or inversion region). Having reached a value of about 273 K (about 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 mesosphere. It is in the stratosphere that the ozone 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. An important component of the stratosphere and mesosphere is O 3, which is formed as a result of photochemical reactions most intensely at an altitude of ~ 30 km. The total mass of O 3 would amount to a layer 1.7-4.0 mm thick at normal pressure, but this is enough to absorb life-destructive UV radiation from the Sun. The destruction of O 3 occurs when it interacts with free radicals, NO, and halogen-containing compounds (including “freons”). In the stratosphere, most of the short-wave part of ultraviolet radiation (180-200 nm) is retained and the energy of short waves is transformed. Under the influence of these rays, magnetic fields change, molecules disintegrate, ionization occurs, and new formation of gases and other chemical compounds occurs. 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 - H 2). At an altitude of 100-400 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 the upper layers of the atmosphere there are free radicals - OH, HO 2, etc. There is almost no water vapor in the stratosphere.

Mesosphere begins at an altitude of 50 km and extends to 80-90 km. The air temperature at an altitude of 75-85 km drops to −88°C. The upper boundary of the mesosphere is the mesopause.

Thermosphere(another name is the ionosphere) - the layer of the atmosphere following the mesosphere - begins at an altitude of 80-90 km and extends up to 800 km. The air temperature in the thermosphere quickly and steadily increases and reaches several hundred and even thousands of degrees.

Exosphere- dispersion zone, the outer part of the thermosphere, located above 800 km. The gas in the exosphere is very rarefied, and from here its particles leak into interplanetary space

The concentrations of gases that make up the atmosphere in the ground layer are almost constant, with the exception of water (H 2 O) and carbon dioxide (CO 2). The change in the chemical composition of the atmosphere depending on altitude is shown in Fig. 4.7.

The change in pressure and temperature of the atmospheric layer up to a height of 35 km is shown in Fig. 4.8.

Fig. 4.7 Change in the chemical composition of the atmosphere in the number of gas atoms per 1 cm3 in height.

The composition of the surface layer of the atmosphere is given in Table 4.1:

Table 4.1

In addition to the gases indicated in the table, the atmosphere contains SO 2, CH 4, NH 3, CO, hydrocarbons, HCl, HF, Hg vapor, I 2, as well as NO and many other gases in small quantities.

Fig. 4.8 Change in pressure and temperature of the atmospheric layer up to an altitude of 35 km

The primary atmosphere of the Earth was similar to the atmosphere of other planets. Thus, 89% of Jupiter's atmosphere is hydrogen. Another approximately 10% is helium, the remaining fractions of a percent are occupied by methane, ammonia and ethane. There is also “snow” - both water and ammonia ice.

The atmosphere of Saturn also consists mainly of helium and hydrogen (Fig. 4.9)

Fig. 4.9 Atmosphere of Saturn

History of the formation of the Earth's atmosphere

1. Initially, it consisted of light gases (hydrogen and helium) captured from interplanetary space. This is the so-called primary atmosphere.

2. Active volcanic activity has led to the saturation of the atmosphere with gases other than hydrogen (hydrocarbons, ammonia, water vapor). This is how it was formed secondary atmosphere.

3. The constant leakage of hydrogen into interplanetary space, chemical reactions occurring in the atmosphere under the influence of ultraviolet radiation, lightning discharges and some other factors led to the formation tertiary atmosphere.

4. With the appearance of living organisms on Earth as a result of photosynthesis, accompanied by the release of oxygen and absorption of carbon dioxide, the composition of the atmosphere began to change and gradually formed the modern quaternary atmosphere (Fig. 4.10). There is, however, data (analysis of the isotopic composition of atmospheric oxygen and that released during photosynthesis) that indicates the geological origin of atmospheric oxygen. The formation of oxygen from water is facilitated by radiation and photochemical reactions. However, their contribution is insignificant. Over the course of various eras, the composition of the atmosphere and oxygen content have undergone very significant changes. It is correlated with global extinctions, glaciations, and other global processes. The establishment of its equilibrium was apparently the result of the appearance of heterotrophic organisms on land and in the ocean and volcanic activity.

Fig. 4.10 Earth's atmosphere in different periods

Contrary to widespread misconception, the content of oxygen and nitrogen in the atmosphere is practically independent of forests. Fundamentally, a forest cannot significantly affect the CO 2 content in the atmosphere because it does not accumulate carbon. The vast majority of carbon is returned to the atmosphere as a result of the oxidation of fallen leaves and trees. A healthy forest is in balance with the atmosphere and gives back exactly as much as it takes into the “breathing” process. Moreover, tropical forests absorb oxygen more often, while the taiga “slightly” releases oxygen. In the 1990s, experiments were carried out to create a closed ecological system (“Biosphere 2”), during which it was not possible to create a stable system with a uniform air composition. The influence of microorganisms led to a decrease in oxygen levels by up to 15% and an increase in the amount of carbon dioxide.

Over the past 100 years, the content of CO 2 in the atmosphere has increased by 10%, with the bulk (360 billion tons) coming from fuel combustion (Fig. 4.11). If the growth rate of fuel combustion continues, then

Fig. 4.11 Progress in increasing carbon dioxide concentrations and average temperatures in recent years.

over the next 50-60 years, the amount of CO 2 in the atmosphere will double and could lead to global climate change.

The principle of the greenhouse effect is illustrated in Figure 4.12.

Rice. 4.12 Principles of the greenhouse effect

The ozone layer is located in the stratosphere at altitudes from 15 to 35 km (Fig. 4.13):

Fig. 4.13 Structure of the ozone layer

In recent years, the concentration of ozone in the stratosphere has fallen sharply, which leads to an increase in the UV background on Earth, especially in the Antarctic region (Fig. 4.14).

Fig. 4.14 Changes in the ozone layer over Antarctica

Hydrosphere

Hydrosphere(Greek Hydor- water + Sphaira- sphere) - the totality of all water reserves of the Earth, the intermittent water shell of the globe, located on the surface and in the thickness of the earth’s crust and representing the totality of oceans, seas and water bodies of land.

3/4 of the Earth's surface is occupied by oceans, seas, reservoirs, and glaciers. The amount of water in the ocean is not constant and changes over time due to various factors. Level fluctuations amount to up to 150 meters at different periods of the Earth’s existence. Groundwater is the connecting link of the entire hydrosphere. Only groundwater occurring at depths of up to 5 km is taken into account. They close the geological water cycle. Their number is estimated at 10-5 thousand cubic km or about 7% of the entire hydrosphere.

Ice and snow in quantity are one of the most important components of the hydrosphere. The mass of water in glaciers is 2.6x10 7 billion tons.

Soil water plays a huge role in the biosphere, because... It is because of water that biochemical processes occur in the soil that ensure soil fertility. The mass of soil water is estimated at 8x10 3 billion tons.

Rivers have the least amount of water in the biosphere. Water reserves in rivers are estimated at 1-2x10 3 billion tons. River waters are usually fresh, their mineralization is unstable and varies with the seasons. Rivers flow along tectonically formed relief depressions.

Atmospheric water combines the hydrosphere and the atmosphere. Atmospheric moisture is always fresh. The mass of atmospheric water is 14x10 3 billion tons. Its importance for the biosphere is very great. The average time for water circulation between the hydrosphere and the atmosphere is 9-10 days.

A significant part of the water is in the biosphere in a bound state in living organisms - 1.1x10 3 billion tons. In an aquatic environment, plants continuously filter water through their surface. On land, plants extract water from the soil with their roots and transpire it with their above-ground parts. To synthesize 1 gram of biomass, plants must evaporate about 100 grams of water (Plankton filters all the ocean water through itself in about 1 year).

The ratio of salty and fresh water in the hydrosphere is shown in Fig. 4.15

Fig. 4.15 The ratio of salt and fresh water in the hydrosphere

Most of the water is concentrated in the ocean, much less in the continental river network and groundwater. There are also large reserves of water in the atmosphere, in the form of clouds and water vapor. Over 96% of the volume of the hydrosphere is made up of seas and oceans, about 2% is groundwater, about 2% is ice and snow, and about 0.02% is land surface water. Some of the water is in a solid state in the form of glaciers, snow cover and permafrost, representing the cryosphere. Surface waters, occupying a relatively small share of the total mass of the hydrosphere, nevertheless play a vital role in the life of our planet, being the main source of water supply, irrigation and water supply. The waters of the hydrosphere are in constant interaction with the atmosphere, the earth's crust and the biosphere. The interaction of these waters and mutual transitions from one type of water to another constitute a complex water cycle on the globe. Life on Earth first originated in the hydrosphere. Only at the beginning of the Paleozoic era did the gradual migration of animals and plant organisms to land begin.

One of the most important functions of the hydrosphere is heat storage, leading to the global water cycle in the biosphere. Heating of surface waters by the Sun (Fig. 4.16) leads to the redistribution of heat throughout the planet.

Fig. 4.16 Temperature of surface ocean waters

Life in the hydrosphere is distributed extremely unevenly. A significant part of the hydrosphere has a weak population of organisms. This is especially true in the ocean depths, where there is little light and relatively low temperatures.

Main surface currents:

In the northern part of the Pacific Ocean: warm - Kuroshio, North Pacific and Alaskan; cold - Californian and Kuril. In the southern part: warm - South Passat and East Australian; cold - Western Winds and Peruvian (Fig. 4.17). The currents of the North Atlantic Ocean are closely coordinated with the currents of the Arctic Ocean. In the central Atlantic, water is heated and moved north by the Gulf Stream, where the water cools and sinks into the depths of the Arctic Ocean.

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Subtitles

Atmospheric boundary

The atmosphere is considered to be that region around the Earth in which the gaseous medium rotates together with the Earth as a single 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 of the atmosphere and space is drawn along the Karman line, located at an altitude of about 100 km, above which aviation flights become completely impossible. NASA uses the 122 kilometers (400,000 ft) mark as the atmospheric limit, where the shuttles switch from powered maneuvering to aerodynamic maneuvering.

Physical properties

In addition to the gases indicated in the table, the atmosphere contains Cl 2 (\displaystyle (\ce (Cl2))) , SO 2 (\displaystyle (\ce (SO2))) , NH 3 (\displaystyle (\ce (NH3))) , CO (\displaystyle ((\ce (CO)))) , O 3 (\displaystyle ((\ce (O3)))) , NO 2 (\displaystyle (\ce (NO2))), hydrocarbons, HCl (\displaystyle (\ce (HCl))) , HF (\displaystyle (\ce (HF))) , HBr (\displaystyle (\ce (HBr))) , HI (\displaystyle ((\ce (HI)))), couples Hg (\displaystyle (\ce (Hg))) , I 2 (\displaystyle (\ce (I2))) , Br 2 (\displaystyle (\ce (Br2))), as well as many other gases in small quantities. The troposphere constantly contains a large amount of suspended solid and liquid particles (aerosol). The rarest gas in the Earth's atmosphere is Rn (\displaystyle (\ce (Rn))) .

The structure of the atmosphere

Atmospheric boundary layer

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 the total water vapor present in the atmosphere. Turbulence and convection are highly developed in the troposphere, clouds appear, and cyclones and anticyclones develop. Temperature decreases with increasing altitude with an average vertical gradient of 0.65°/100 meters.

Tropopause

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

Stratosphere

A layer of the atmosphere located at an altitude of 11 to 50 km. Characterized by a slight change in temperature in the 11-25 km layer (lower layer of the stratosphere) and an increase in the 25-40 km layer from minus 56.5 to plus 0.8 ° C (upper layer of the stratosphere or inversion region). 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 mesosphere.

Stratopause

The boundary layer of the atmosphere between the stratosphere and mesosphere. In the vertical temperature distribution there is a maximum (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 to high altitudes. Under the influence of solar radiation and cosmic radiation, ionization of the air (“auroras”) occurs - 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 adjacent above the thermosphere. In this region, the absorption of solar radiation is negligible and the temperature does not actually change with altitude.

Exosphere (scattering sphere)

Up to an altitude of 100 km, the atmosphere is a homogeneous, well-mixed mixture of gases. In higher layers, the distribution of gases by 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 minus 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 in time and space are observed.

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

Review

Based on electrical properties in the atmosphere, they distinguish neutrosphere And ionosphere .

Depending on the composition of the gas in the atmosphere, they emit homosphere And heterosphere. Heterosphere- This is the area where gravity affects the separation of gases, since their mixing at such an altitude is negligible. This implies a 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 the 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 begins to experience oxygen starvation and without adaptation, a person’s performance is significantly reduced. The physiological zone of the atmosphere ends here. Human breathing becomes impossible at an altitude of 9 km, although up to approximately 115 km the atmosphere contains oxygen.

The atmosphere supplies us with the oxygen necessary for breathing. However, due to the drop in the total pressure of the atmosphere, as you rise to altitude, the partial pressure of oxygen decreases accordingly.

History of atmospheric formation

According to the most common theory, the Earth's atmosphere has had three different compositions throughout its history. Initially, it consisted of light gases (hydrogen and helium) captured from interplanetary space. This is the 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 it was formed secondary atmosphere. This atmosphere was restorative. Further, the process of atmosphere formation 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 nitrogen is due to the oxidation of the ammonia-hydrogen atmosphere by molecular oxygen O 2 (\displaystyle (\ce (O2))), which began to come from the surface of the planet as a result of photosynthesis, starting 3 billion years ago. Also nitrogen N 2 (\displaystyle (\ce (N2))) released into the atmosphere as a result of denitrification of nitrates and other nitrogen-containing compounds. Nitrogen is oxidized by ozone to NO (\displaystyle ((\ce (NO)))) in the upper layers of the atmosphere.

Nitrogen N 2 (\displaystyle (\ce (N2))) reacts only under specific conditions (for example, during a lightning discharge). The oxidation of molecular nitrogen by ozone during electrical discharges is used in small quantities in the industrial production of nitrogen fertilizers. Cyanobacteria (blue-green algae) and nodule bacteria, which form rhizobial symbiosis with leguminous plants, which can be effective green manures - plants that do not deplete, but enrich the soil with natural fertilizers, can oxidize it with low energy consumption and convert it into a biologically active form.

Oxygen

The composition of the atmosphere began to change radically with the appearance 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, ferrous form of iron contained in the oceans and others. At the end of this stage, the oxygen content in the atmosphere began to increase. 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.

Noble gases

Air pollution

Recently, humans have begun to influence the evolution of the atmosphere. The result of human activity has been a constant increase in the content of carbon dioxide in the atmosphere due to the combustion of hydrocarbon fuels accumulated in previous geological eras. Enormous quantities are consumed during photosynthesis and are 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 industrial activity. Over the last 100 years content CO 2 (\displaystyle (\ce (CO2))) in the atmosphere increased by 10%, with the bulk (360 billion tons) coming from fuel combustion. If the growth rate of fuel combustion continues, then in the next 200-300 years the amount CO 2 (\displaystyle (\ce (CO2))) in the atmosphere will double and may lead to

Atmosphere (from ancient Greek ἀτμός - steam and σφαῖρα - ball) is a gas shell (geosphere) surrounding planet Earth. Its inner surface covers the hydrosphere and partly the earth's crust, while its outer surface borders the near-Earth part of outer space.

The set of branches of physics and chemistry that study the atmosphere is usually called atmospheric physics. The atmosphere determines the weather on the Earth's surface, meteorology studies weather, and climatology deals with long-term climate variations.

Physical properties

The thickness of the atmosphere is approximately 120 km from the Earth's surface. The total mass of air in the atmosphere is (5.1-5.3) 1018 kg. Of these, the mass of dry air is (5.1352 ± 0.0003) 1018 kg, the total mass of water vapor is on average 1.27 1016 kg.

The molar mass of clean dry air is 28.966 g/mol, and the density of air at the sea surface is approximately 1.2 kg/m3. The pressure at 0 °C at sea level is 101.325 kPa; critical temperature - −140.7 °C (~132.4 K); critical pressure - 3.7 MPa; Cp at 0 °C - 1.0048·103 J/(kg·K), Cv - 0.7159·103 J/(kg·K) (at 0 °C). Solubility of air in water (by mass) at 0 °C - 0.0036%, at 25 °C - 0.0023%.

The following are accepted as “normal conditions” at the Earth’s surface: density 1.2 kg/m3, barometric pressure 101.35 kPa, temperature plus 20 °C and relative humidity 50%. These conditional indicators have purely engineering significance.

Chemical composition

The Earth's atmosphere arose as a result of the release of gases during volcanic eruptions. With the advent of the oceans and the biosphere, it was formed due to gas exchange with water, plants, animals and the products of their decomposition in soils and swamps.

Currently, the Earth's atmosphere consists mainly of gases and various impurities (dust, water droplets, ice crystals, sea salts, combustion products).

The concentration of gases that make up the atmosphere is almost constant, with the exception of water (H2O) and carbon dioxide (CO2).

Composition of dry air


Nitrogen
Oxygen
Argon
Water
Carbon dioxide
Neon
Helium
Methane
Krypton
Hydrogen
Xenon
Nitrous oxide

In addition to the gases indicated in the table, the atmosphere contains SO2, NH3, CO, ozone, hydrocarbons, HCl, HF, Hg vapor, I2, as well as NO and many other gases in small quantities. The troposphere constantly contains a large amount of suspended solid and liquid particles (aerosol).

The structure 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 the total water vapor present in the atmosphere. Turbulence and convection are highly developed in the troposphere, clouds arise, and cyclones and anticyclones develop. Temperature decreases with increasing altitude with an average vertical gradient of 0.65°/100 m

Tropopause

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

Stratosphere

A layer of the atmosphere located at an altitude of 11 to 50 km. Characterized by a slight change in temperature in the 11-25 km layer (lower layer of the stratosphere) and an increase in temperature in the 25-40 km layer from −56.5 to 0.8 ° C (upper layer of the stratosphere or inversion region). 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 mesosphere.

Stratopause

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

Mesosphere

The mesosphere begins at an altitude of 50 km and extends to 80-90 km. Temperature decreases with height with an average vertical gradient of (0.25-0.3)°/100 m. The main energy process is radiant heat transfer. Complex photochemical processes involving free radicals, vibrationally excited molecules, etc. cause atmospheric luminescence.

Mesopause

Transitional layer between the mesosphere and thermosphere. There is a minimum in the vertical temperature distribution (about -90 °C).

Karman Line

The height above sea level, which is conventionally accepted as the boundary between the Earth's atmosphere and space. According to the FAI definition, the Karman line is located at an altitude of 100 km above sea level.

Boundary of the Earth's atmosphere

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 to high altitudes. Under the influence of ultraviolet and x-ray solar radiation and cosmic radiation, ionization of the air (“auroras”) occurs - 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 adjacent to the thermosphere. In this region, the absorption of solar radiation is negligible and the temperature does not actually change with altitude.

Exosphere (scattering sphere)

The exosphere is a dispersion zone, the outer part of the thermosphere, located above 700 km. The gas in the exosphere is very rarefied, and from here its particles leak into interplanetary space (dissipation).

Up to an altitude of 100 km, the atmosphere is a homogeneous, well-mixed mixture of gases. In higher layers, the distribution of gases by 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 in time and space are observed.

At an altitude of about 2000-3500 km, the exosphere gradually turns into the so-called near-space vacuum, which is filled with highly rarefied particles of interplanetary gas, mainly hydrogen atoms. But this gas represents only part of the interplanetary matter. The other part consists of dust particles of cometary and meteoric origin. In addition to extremely rarefied dust 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 - 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 neutronosphere 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, homosphere and heterosphere are distinguished. The heterosphere is an area where gravity affects the separation of gases, since their mixing at such a height is negligible. This implies a 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 the turbopause; it lies at an altitude of about 120 km.

Other properties of the atmosphere and effects on the human body

The human lungs constantly contain about 3 liters of alveolar air. The partial pressure of oxygen in alveolar air at normal atmospheric pressure is 110 mmHg. Art., carbon dioxide pressure - 40 mm Hg. Art., and water vapor - 47 mm Hg. Art. With increasing altitude, oxygen pressure drops, and the total vapor pressure of water and carbon dioxide in the lungs remains almost constant - about 87 mm Hg. Art. The supply of oxygen to the lungs will completely stop when the ambient air pressure 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 altitude, 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 is dangerous for humans.

As we rise to an ever greater height above the Earth's surface, such familiar phenomena observed in the lower layers of the atmosphere as sound propagation, the occurrence of aerodynamic lift and drag, heat transfer by convection, etc. gradually weaken and then completely disappear.

In rarefied layers of air, sound propagation 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 lies the conventional Karman line, beyond which the region of purely ballistic flight begins, which can only be controlled using reactive forces.

At altitudes above 100 km, the atmosphere is deprived of another remarkable property - the ability to absorb, conduct and transmit thermal energy by convection (i.e. by mixing air). This means that various elements of equipment on the orbital space station will not be able to be cooled from the outside in the same way as is usually done on an airplane - with the help of air jets and air radiators. At this altitude, as in space generally, the only way to transfer heat is thermal radiation.

History of atmospheric formation

According to the most common theory, the Earth's atmosphere has had three different compositions over time. Initially, it consisted of light gases (hydrogen and helium) captured from interplanetary space. This is the 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 the secondary atmosphere was formed (about three billion years before the present day). This atmosphere was restorative. Further, the process of atmosphere formation 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 of a tertiary atmosphere, characterized by much less hydrogen and much more nitrogen and carbon dioxide (formed as a result of chemical reactions from ammonia and hydrocarbons).

Nitrogen

The formation of a large amount of nitrogen N2 is due to the oxidation of the ammonia-hydrogen atmosphere by molecular oxygen O2, which began to come from the surface of the planet as a result of photosynthesis, starting 3 billion years ago. Nitrogen N2 is also released into the atmosphere as a result of denitrification of nitrates and other nitrogen-containing compounds. Nitrogen is oxidized by ozone to NO in the upper atmosphere.

Nitrogen N2 reacts only under specific conditions (for example, during a lightning discharge). The oxidation of molecular nitrogen by ozone during electrical discharges is used in small quantities in the industrial production of nitrogen fertilizers. Cyanobacteria (blue-green algae) and nodule bacteria that form rhizobial symbiosis with leguminous plants, the so-called, can oxidize it with low energy consumption and convert it into a biologically active form. green manure.

Oxygen

The composition of the atmosphere began to change radically with the appearance 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, ferrous form of iron contained in the oceans, etc. At the end of this stage, the oxygen content in the atmosphere began to increase. 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.

During the Phanerozoic, the composition of the atmosphere and oxygen content underwent changes. They correlated primarily with the rate of deposition of organic sediment. Thus, during periods of coal accumulation, the oxygen content in the atmosphere apparently significantly exceeded the modern level.

Carbon dioxide

The CO2 content 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 1012 tons) is formed due to carbon dioxide, nitrogen and water vapor contained in the atmospheric air. Organics buried in the ocean, swamps and forests turn into coal, oil and natural gas.

Noble gases

The source of noble gases - argon, helium and krypton - is volcanic eruptions and the decay of radioactive elements. The Earth in general and the atmosphere in particular are depleted of inert gases compared to space. It is believed that the reason for this lies in the continuous leakage of gases into interplanetary space.

Air pollution

Recently, humans have begun to influence the evolution of the atmosphere. The result of his activities was a constant increase in the content of carbon dioxide in the atmosphere due to the combustion of hydrocarbon fuels accumulated in previous geological eras. Huge amounts of CO2 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 industrial activity. Over the past 100 years, the CO2 content in the atmosphere has increased by 10%, with the bulk (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 CO2 in the atmosphere will double and could lead to global climate change.

Fuel combustion is the main source of polluting gases (CO, NO, SO2). Sulfur dioxide is oxidized by atmospheric oxygen to SO3, and nitrogen oxide to NO2 in the upper layers of the atmosphere, which in turn interact with water vapor, and the resulting sulfuric acid H2SO4 and nitric acid HNO3 fall to the surface of the Earth in the form of the so-called. acid rain. The use of internal combustion engines leads to significant atmospheric pollution with nitrogen oxides, hydrocarbons and lead compounds (tetraethyl lead) Pb(CH3CH2)4.

Aerosol pollution of the atmosphere is caused by both natural causes (volcanic eruptions, dust storms, entrainment of drops of sea water and plant pollen, etc.) and human economic activities (mining ores and building materials, burning fuel, making cement, etc.). Intense large-scale release of particulate matter into the atmosphere is one of the possible causes of climate change on the planet.

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He is invisible, and yet we cannot live without him.

Each of us understands how necessary air is for life. The expression “It is as necessary as air” can be heard when talking about something very important for a person’s life. We know from childhood that living and breathing are practically the same thing.

Do you know how long a person can live without air?

Not all people know how much air they breathe. It turns out that in a day, taking about 20,000 breaths and exhalations, a person passes 15 kg of air through his lungs, while he absorbs only about 1.5 kg of food and 2-3 kg of water. At the same time, air is something we take for granted, like the sunrise every morning. Unfortunately, we only feel it when there is not enough of it, or when it is polluted. We forget that all life on Earth, developing over millions of years, has adapted to life in an atmosphere of a certain natural composition.

Let's see what air consists of.

And let's conclude: Air is a mixture of gases. Oxygen in it is about 21% (approximately 1/5 by volume), nitrogen accounts for about 78%. The remaining required components are inert gases (primarily argon), carbon dioxide, and other chemical compounds.

The study of the composition of air began in the 18th century, when chemists learned to collect gases and conduct experiments with them. If you are interested in the history of science, watch a short film dedicated to the history of the discovery of air.

The oxygen contained in the air is required for the respiration of living organisms. What is the essence of the breathing process? As you know, in the process of breathing the body consumes oxygen from the air. Air oxygen is required for numerous chemical reactions that continuously occur in all cells, tissues and organs of living organisms. During these reactions, with the participation of oxygen, those substances that came with food slowly “burn” to form carbon dioxide. At the same time, the energy contained in them is released. Due to this energy, the body exists, using it for all functions - the synthesis of substances, muscle contraction, the functioning of all organs, etc.

In nature, there are also some microorganisms that can use nitrogen in the process of life. Due to the carbon dioxide contained in the air, the process of photosynthesis occurs and the Earth's biosphere as a whole lives.

As you know, the air envelope of the Earth is called the atmosphere. The atmosphere extends approximately 1000 km from the Earth - it is a kind of barrier between the Earth and space. According to the nature of temperature changes in the atmosphere, there are several layers:

Atmosphere- This is a kind of barrier between Earth and space. It softens the effects of cosmic radiation and provides conditions on Earth for the development and existence of life. It is the atmosphere of the first of the earth's shells that meets the sun's rays and absorbs the hard ultraviolet radiation of the Sun, which has a detrimental effect on all living organisms.

Another “merit” of the atmosphere is related to the fact that it almost completely absorbs the Earth’s own invisible thermal (infrared) radiation and returns most of it back. That is, the atmosphere, transparent to the sun’s rays, at the same time represents an air “blanket” that does not allow the Earth to cool. Thus, our planet maintains an optimal temperature for the life of a variety of living beings.

The composition of the modern atmosphere is unique, the only one in our planetary system.

The Earth's primary atmosphere consisted of methane, ammonia and other gases. Along with the development of the planet, the atmosphere changed significantly. Living organisms played a leading role in the formation of the composition of atmospheric air that arose and is maintained with their participation at the present time. You can look in more detail at the history of the formation of the atmosphere on Earth.

Natural processes of both consumption and formation of atmospheric components approximately balance each other, that is, they ensure a constant composition of the gases that make up the atmosphere.

Without human economic activity, nature copes with such phenomena as the entry into the atmosphere of volcanic gases, smoke from natural fires, and dust from natural dust storms. These emissions disperse into the atmosphere, settle, or fall to the Earth's surface as precipitation. Soil microorganisms are taken for them, and ultimately process them into carbon dioxide, sulfur and nitrogen compounds of the soil, that is, into the “ordinary” components of air and soil. This is the reason why atmospheric air has, on average, a constant composition. With the appearance of man on Earth, first gradually, then rapidly and now threateningly, the process of changing the gas composition of the air and destroying the natural stability of the atmosphere began.About 10,000 years ago, people learned to use fire. Combustion products of various types of fuel have been added to natural sources of pollution. At first it was wood and other types of plant material.

Currently, the most harmful to the atmosphere is caused by artificially produced fuel - petroleum products (gasoline, kerosene, diesel oil, fuel oil) and synthetic fuel. When burned, they form nitrogen and sulfur oxides, carbon monoxide, heavy metals and other toxic substances of non-natural origin (pollutants).

Considering the huge scale of technology use these days, one can imagine how many engines of cars, airplanes, ships and other equipment are generated every second. killed the atmosphere Aleksashina I.Yu., Kosmodamiansky A.V., Oreshchenko N.I. Natural science: Textbook for 6th grade of general education institutions. – St. Petersburg: SpetsLit, 2001. – 239 p. .

Why are trolleybuses and trams considered environmentally friendly modes of transport compared to buses?

Particularly dangerous for all living things are those stable aerosol systems that are formed in the atmosphere along with acidic and many other gaseous industrial wastes. Europe is one of the most densely populated and industrialized parts of the world. A powerful transport system, large industry, high consumption of fossil fuels and mineral raw materials lead to a noticeable increase in the concentrations of pollutants in the air. In almost all major cities of Europe there is smog Smog is an aerosol consisting of smoke, fog and dust, one of the types of air pollution in large cities and industrial centers. For more details see: http://ru.wikipedia.org/wiki/Smog and increased levels of dangerous pollutants such as nitrogen and sulfur oxides, carbon monoxide, benzene, phenols, fine dust, etc. are regularly recorded in the air.

There is no doubt that there is a direct connection between the increase in the content of harmful substances in the atmosphere and the increase in allergic and respiratory diseases, as well as a number of other diseases.

Serious measures are needed in connection with the increase in the number of cars in cities and the industrial development planned in a number of Russian cities, which will inevitably increase the amount of pollutant emissions into the atmosphere.

See how the problems of air purity are being solved in the “green capital of Europe” - Stockholm.

A set of measures to improve air quality must necessarily include improving the environmental performance of cars; construction of gas purification systems at industrial enterprises; the use of natural gas, rather than coal, as fuel in energy enterprises. Now in every developed country there is a service for monitoring the state of air cleanliness in cities and industrial centers, which has somewhat improved the current bad situation. Thus, in St. Petersburg there is an automated system for monitoring the atmospheric air of St. Petersburg (ASM). Thanks to it, not only state authorities and local governments, but also city residents can learn about the state of the atmospheric air.

The health of residents of St. Petersburg - a metropolis with a developed network of transport highways - is influenced, first of all, by the main pollutants: carbon monoxide, nitrogen oxide, nitrogen dioxide, suspended substances (dust), sulfur dioxide, which enter the atmospheric air of the city from emissions from thermal power plants, industry, and transport. Currently, the share of emissions from motor vehicles is 80% of the total emissions of major pollutants. (According to expert estimates, in more than 150 cities of Russia, motor transport has the predominant influence on air pollution).

How are things going in your city? What do you think can and should be done to make the air in our cities cleaner?

Information is provided on the level of air pollution in the areas where AFM stations are located in St. Petersburg.

It must be said that in St. Petersburg there has been a tendency towards a decrease in emissions of pollutants into the atmosphere, however, the reasons for this phenomenon are associated mainly with a decrease in the number of operating enterprises. It is clear that from an economic point of view this is not the best way to reduce pollution.

Let's draw conclusions.

The air shell of the Earth - the atmosphere - is necessary for the existence of life. The gases that make up the air are involved in such important processes as respiration and photosynthesis. The atmosphere reflects and absorbs solar radiation and thus protects living organisms from harmful X-rays and ultraviolet rays. Carbon dioxide traps thermal radiation from the earth's surface. The Earth's atmosphere is unique! Our health and life depend on it.

Man mindlessly accumulates waste from his activities in the atmosphere, which causes serious environmental problems. We all need to not only realize our responsibility for the state of the atmosphere, but also, to the best of our ability, do what we can to preserve the cleanliness of the air, the basis of our lives.