The world around us formed from three very different parts: land, water and air. Each of them is unique and interesting in its own way. Now we will talk only about the last of them. What is atmosphere? How did it come about? What does it consist of and into what parts is it divided? All these questions are extremely interesting.

The name “atmosphere” itself is formed from two words Greek origin, translated into Russian they mean “steam” and “ball”. And if you look at the exact definition, you can read the following: “The atmosphere is the air shell of the planet Earth, which rushes along with it in outer space.” It developed in parallel with the geological and geochemical processes that took place on the planet. And today all processes occurring in living organisms depend on it. Without an atmosphere, the planet would become a lifeless desert, like the Moon.

What does it consist of?

The question of what the atmosphere is and what elements are included in it has interested people for a long time. The main components of this shell were known already in 1774. They were installed by Antoine Lavoisier. He discovered that the composition of the atmosphere was largely composed of nitrogen and oxygen. Over time, its components were refined. And now it is known that it contains many other gases, as well as water and dust.

Let's take a closer look at what makes up the Earth's atmosphere near its surface. The most common gas is nitrogen. It contains slightly more than 78 percent. But, despite such a large amount, nitrogen is practically inactive in the air.

The next element in quantity and very important in importance is oxygen. This gas contains almost 21%, and it exhibits very high activity. Its specific function is to oxidize dead organic matter, which decomposes as a result of this reaction.

Low but important gases

The third gas that is part of the atmosphere is argon. It's a little less than one percent. After it come carbon dioxide with neon, helium with methane, krypton with hydrogen, xenon, ozone and even ammonia. But there are so few of them that the percentage of such components is equal to hundredths, thousandths and millionths. Of these, only carbon dioxide plays significant role because he is building material, which plants need for photosynthesis. Its other important function is to block radiation and absorb some of the sun's heat.

Another small but important gas, ozone exists to trap ultraviolet radiation coming from the Sun. Thanks to this property, all life on the planet is reliably protected. On the other hand, ozone affects the temperature of the stratosphere. Due to the fact that it absorbs this radiation, the air heats up.

The constancy of the quantitative composition of the atmosphere is maintained by non-stop mixing. Its layers move both horizontally and vertically. Therefore, anywhere on the globe there is enough oxygen and no excess carbon dioxide.

What else is in the air?

It should be noted that steam and dust can be found in the airspace. The latter consists of pollen and soil particles; in the city they are joined by impurities of solid emissions from exhaust gases.

But there is a lot of water in the atmosphere. Under certain conditions, it condenses and clouds and fog appear. In essence, these are the same thing, only the former appear high above the surface of the Earth, and the latter spreads along it. Clouds take different shapes. This process depends on the height above the Earth.

If they formed 2 km above land, then they are called layered. It is from them that rain pours on the ground or snow falls. Above them, up to a height of 8 km, are formed cumulus clouds. They are always the most beautiful and picturesque. They are the ones who look at them and wonder what they look like. If such formations appear in the next 10 km, they will be very light and airy. Their name is feathery.

What layers is the atmosphere divided into?

Although they have very different temperatures from each other, it is very difficult to tell at what specific height one layer begins and the other ends. This division is very conditional and is approximate. However, the layers of the atmosphere still exist and perform their functions.

The lowest part of the air shell is called the troposphere. Its thickness increases as it moves from the poles to the equator from 8 to 18 km. This is the warmest part of the atmosphere because the air in it is heated by earth's surface. Most of the water vapor is concentrated in the troposphere, which is why clouds form, precipitation falls, thunderstorms rumble and winds blow.

The next layer is about 40 km thick and is called the stratosphere. If an observer moves into this part of the air, he will find that the sky has turned purple. This is explained by the low density of the substance, which practically does not scatter the sun's rays. It is in this layer that jet planes fly. All open spaces are open for them, since there are practically no clouds. Inside the stratosphere there is a layer consisting of large quantity ozone.

After it come the stratopause and mesosphere. The latter is about 30 km thick. It is characterized by a sharp decrease in air density and temperature. The sky appears black to the observer. Here you can even watch the stars during the day.

Layers in which there is practically no air

The structure of the atmosphere continues with a layer called the thermosphere - the longest of all the others, its thickness reaches 400 km. This layer is distinguished by its enormous temperature, which can reach 1700 °C.

The last two spheres are often combined into one and called the ionosphere. This is due to the fact that reactions occur in them with the release of ions. It is these layers that make it possible to observe such a natural phenomenon as the northern lights.

The next 50 km from the Earth are allocated to the exosphere. This is the outer shell of the atmosphere. It disperses air particles into space. Weather satellites usually move in this layer.

The Earth's atmosphere ends with the magnetosphere. It is she who sheltered most of the planet’s artificial satellites.

After all that has been said, there should be no questions left about what the atmosphere is. If you have doubts about its necessity, they can be easily dispelled.

The meaning of atmosphere

The main function of the atmosphere is to protect the surface of the planet from overheating in daytime and excessive cooling at night. The next important purpose of this shell, which no one will dispute, is to supply oxygen to all living beings. Without this they would suffocate.

Most meteorites burn up in the upper layers, never reaching the Earth's surface. And people can admire the flying lights, mistaking them for shooting stars. Without an atmosphere, the entire Earth would be littered with craters. And protection from solar radiation has already been discussed above.

How does a person influence the atmosphere?

Very negative. This is due to the growing activity of people. The main share of all negative aspects falls on industry and transport. By the way, it is cars that emit almost 60% of all pollutants that penetrate into the atmosphere. The remaining forty are divided between energy and industry, as well as waste disposal industries.

The list of harmful substances that daily replenish the air is very long. Due to transport in the atmosphere there are: nitrogen and sulfur, carbon, blue and soot, as well as a strong carcinogen that causes skin cancer - benzopyrene.

The industry accounts for such chemical elements: sulfur dioxide, hydrocarbon and hydrogen sulfide, ammonia and phenol, chlorine and fluorine. If the process continues, then soon the answers to the questions: “What is the atmosphere? What does it consist of? will be completely different.

STRUCTURE OF THE ATMOSPHERE

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

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) 10 18 kg. Of these, the mass of dry air is (5.1352 ± 0.0003) 10 18 kg, the total mass of water vapor is on average 1.27 10 16 kg.

The molar mass of clean dry air is 28.966 g/mol, 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; critical pressure - 3.7 MPa; C p at 0 °C - 1.0048·10 3 J/(kg·K), C v - 0.7159·10 3 J/(kg·K) (at 0 °C). 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.

The structure of the atmosphere

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

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

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

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

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

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

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

Stratosphere(from Latin stratum - flooring, layer) - a layer of the atmosphere located at an altitude of 11 to 50 km. 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. The air density in the stratosphere is tens and hundreds of times less than at sea level.

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. Ozone (O 3) is formed as a result of photochemical reactions most intensively at an altitude of ~30 km. The total mass of O 3 would be at normal pressure a layer 1.7-4.0 mm thick, but this is enough to absorb life-destructive ultraviolet radiation 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 beyond high layers under the influence of solar radiation, gas molecules dissociate into atoms (above 80 km CO 2 and H 2 dissociate, above 150 km - O 2, above 300 km - N 2). At an altitude of 200-500 km, ionization of gases also occurs in the ionosphere; at an altitude of 320 km, the concentration of charged particles (O + 2, O − 2, N + 2) is ~ 1/300 of the concentration of neutral particles. In the upper layers of the atmosphere there are free radicals - OH, HO 2, etc.

There is almost no water vapor in the stratosphere.

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

IN lately In US military circles, much attention is paid to the development of layers of the stratosphere above 20 km, often called “pre-space”. « near space» ). It is assumed that unmanned airships and solar-powered aircraft (like NASA's Pathfinder) will be able to long time be at an altitude of about 30 km and provide surveillance and communications to very large areas, while remaining low-vulnerable to air defense systems; Such devices will be many times cheaper than satellites.

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

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

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

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

The gas composition of the mesosphere, like that of the underlying atmospheric layers, is constant and contains about 80% nitrogen and 20% oxygen.

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

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

Noctilucent clouds may appear in the mesosphere.

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

Mesopause

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

Mesopause occurs not only on Earth, but also on other planets that have an atmosphere.

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

According to the Fédération Aéronautique Internationale (FAI) definition, the Karman line is located at an altitude of 100 km above sea level.

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

The Earth's atmosphere continues beyond the Karman line. The outer part of the earth's atmosphere, the exosphere, extends to an altitude of 10 thousand km or more; at this altitude, the atmosphere consists mainly of hydrogen atoms that are capable of leaving the atmosphere.

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

The Earth's atmosphere is the gaseous envelope of our planet. By the way, almost everyone has similar shells celestial bodies, starting from the planets solar system and ending with large asteroids. depends on many factors - the size of its speed, mass and many other parameters. But only the shell of our planet contains the components that allow us to live.

Earth's atmosphere: brief history emergence

It is believed that at the beginning of its existence our planet had no gas shell at all. But the young, newly formed celestial body was constantly evolving. The Earth's primary atmosphere was formed as a result of constant volcanic eruptions. This is how, over many thousands of years, a shell of water vapor, nitrogen, carbon and other elements (except oxygen) formed around the Earth.

Since the amount of moisture in the atmosphere is limited, its excess turned into precipitation - this is how seas, oceans and other bodies of water were formed. The first organisms that populated the planet appeared and developed in the aquatic environment. Most of them belonged to plant organisms that produce oxygen through photosynthesis. Thus, the Earth's atmosphere began to fill with this vital gas. And as a result of the accumulation of oxygen, the ozone layer was formed, which protected the planet from the harmful effects of ultraviolet radiation. It is these factors that created all the conditions for our existence.

The structure of the Earth's atmosphere

As you know, the gas shell of our planet consists of several layers - the troposphere, stratosphere, mesosphere, thermosphere. It is impossible to draw clear boundaries between these layers - it all depends on the time of year and the latitude of the planet.

The troposphere is the lower part of the gas shell, the height of which averages from 10 to 15 kilometers. This is where most of the moisture is concentrated. By the way, this is where all the moisture is located and clouds form. Due to the oxygen content, the troposphere supports the life activity of all organisms. In addition, it is crucial in shaping the weather and climatic features of the area - not only clouds, but also winds are formed here. Temperature drops with altitude.

Stratosphere - starts from the troposphere and ends at an altitude of 50 to 55 kilometers. Here the temperature increases with altitude. This part of the atmosphere contains virtually no water vapor, but does have an ozone layer. Sometimes here you can notice the formation of “pearl” clouds, which can only be seen at night - they are believed to be represented by highly condensed water drops.

The mesosphere stretches up to 80 kilometers up. In this layer you can notice a sharp drop in temperature as you move up. Turbulence is also highly developed here. By the way, so-called “noctilucent clouds” are formed in the mesosphere, which consist of small ice crystals - they can only be seen at night. It is interesting that there is practically no air at the upper boundary of the mesosphere - it is 200 times less than near the earth's surface.

The thermosphere is the upper layer of the earth's gas shell, in which it is customary to distinguish between the ionosphere and the exosphere. Interestingly, the temperature here rises very sharply with altitude - at an altitude of 800 kilometers from the earth's surface it is more than 1000 degrees Celsius. The ionosphere is characterized by highly diluted air and a huge content of active ions. As for the exosphere, this part of the atmosphere smoothly passes into interplanetary space. It is worth noting that the thermosphere does not contain air.

It can be noted that the Earth's atmosphere is a very important part of our planet, which remains a decisive factor in the emergence of life. It ensures life activity, maintains the existence of the hydrosphere (the watery shell of the planet) and protects from ultraviolet radiation.

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. 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, air ionization occurs (“ auroras") - 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, a noticeable decrease in the size of this layer occurs.

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)

Atmospheric layers up to an altitude of 120 km

The exosphere is the 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 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 ~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.

The atmosphere is what makes life possible on Earth. We receive the very first information and facts about the atmosphere back in elementary school. In high school, we become more familiar with this concept in geography lessons.

Concept of earth's atmosphere

Not only the Earth, but also other celestial bodies have an atmosphere. This is the name given to the gaseous shell surrounding the planets. The composition of this gas layer different planets is significantly different. Let's look at the basic information and facts about otherwise called air.

Its most important component is oxygen. Some people mistakenly think that the earth's atmosphere consists entirely of oxygen, but in fact, air is a mixture of gases. It contains 78% nitrogen and 21% oxygen. The remaining one percent includes ozone, argon, carbon dioxide, and water vapor. Let percentage These gases are small in number, but they perform an important function - they absorb a significant part of the solar radiant energy, thereby preventing the luminary from turning all life on our planet into ashes. The properties of the atmosphere change depending on altitude. For example, at an altitude of 65 km, nitrogen is 86% and oxygen is 19%.

Composition of the Earth's atmosphere

• Carbon dioxide necessary for plant nutrition. It appears in the atmosphere as a result of the process of respiration of living organisms, decay, and combustion. Its absence in the atmosphere would make the existence of any plants impossible.
• Oxygen- a vital component of the atmosphere for humans. Its presence is a condition for the existence of all living organisms. It makes up about 20% of the total volume of atmospheric gases.
• Ozone is a natural absorber of solar ultraviolet radiation, which has a detrimental effect on living organisms. Most of it forms a separate layer of the atmosphere - the ozone screen. Recently, human activity has led to the fact that it is gradually beginning to collapse, but since it is of great importance, active work is being carried out to preserve and restore it.
• water vapor determines air humidity. Its content may vary depending on various factors: air temperature, territorial location, season. At low temperatures there is very little water vapor in the air, maybe less than one percent, and at high temperatures its amount reaches 4%.
• In addition to all of the above, the composition of the earth’s atmosphere always contains a certain percentage solid and liquid impurities. This is soot, ash, sea ​​salt, dust, water drops, microorganisms. They can get into the air both naturally and anthropogenically.

Layers of the atmosphere

The temperature, density, and quality composition of the air are not the same at different altitudes. Because of this, it is customary to distinguish different layers of the atmosphere. Each of them has its own characteristics. Let's find out what layers of the atmosphere are distinguished:

• Troposphere - this layer of the atmosphere is closest to the Earth's surface. Its height is 8-10 km above the poles and 16-18 km in the tropics. 90% of all water vapor in the atmosphere is located here, so active cloud formation occurs. Also in this layer processes such as air (wind) movement, turbulence, and convection are observed. Temperatures range from +45 degrees at midday in the warm season in the tropics to -65 degrees at the poles.
• The stratosphere is the second most distant layer of the atmosphere. Located at an altitude of 11 to 50 km. In the lower layer of the stratosphere the temperature is approximately -55; moving away from the Earth it rises to +1˚С. This region is called an inversion and is the boundary of the stratosphere and mesosphere.
• The mesosphere is located at an altitude of 50 to 90 km. The temperature at its lower boundary is about 0, at the upper it reaches -80...-90 ˚С. Meteorites entering the Earth's atmosphere completely burn up in the mesosphere, causing airglows to occur here.
• The thermosphere is approximately 700 km thick. The northern lights appear in this layer of the atmosphere. They appear due to the influence of cosmic radiation and radiation emanating from the Sun.
• The exosphere is a zone of air dispersion. Here the concentration of gases is small and they gradually escape into interplanetary space.

The boundary between the earth's atmosphere and outer space is considered to be 100 km. This line is called the Karman line.

Atmospheric pressure

When listening to the weather forecast, we often hear barometric pressure readings. But what does atmospheric pressure mean, and how can it affect us?

We figured out that air consists of gases and impurities. Each of these components has its own weight, which means that the atmosphere is not weightless, as was believed until the 17th century. Atmospheric pressure is the force with which all layers of the atmosphere press on the surface of the Earth and on all objects.

Scientists carried out complex calculations and proved that one square meter area the atmosphere presses with a force of 10,333 kg. This means that the human body is subject to air pressure, the weight of which is 12-15 tons. Why don't we feel this? It is our internal pressure that saves us, which balances the external. You can feel the pressure of the atmosphere while on an airplane or high in the mountains, since the atmospheric pressure at altitude is much less. In this case, physical discomfort, blocked ears, and dizziness are possible.

A lot can be said about the surrounding atmosphere. We know a lot about her interesting facts, and some of them may seem surprising:

• The weight of the earth's atmosphere is 5,300,000,000,000,000 tons.
• It promotes sound transmission. At an altitude of more than 100 km, this property disappears due to changes in the composition of the atmosphere.
• The movement of the atmosphere is provoked by uneven heating of the Earth's surface.
• A thermometer is used to determine the air temperature, and a barometer is used to determine the pressure of the atmosphere.
• The presence of an atmosphere saves our planet from 100 tons of meteorites every day.
• The composition of the air was fixed for several hundred million years, but began to change with the onset of rapid industrial activity.
• The atmosphere is believed to extend upward to a height of 3000 km.

The importance of the atmosphere for humans

The physiological zone of the atmosphere is 5 km. At an altitude of 5000 m above sea level, a person begins to experience oxygen starvation, which is expressed in a decrease in his performance and deterioration in well-being. This shows that a person cannot survive in a space where there is no this amazing mixture of gases.

All information and facts about the atmosphere only confirm its importance for people. Thanks to its presence, it became possible to develop life on Earth. Already today, having assessed the scale of harm that humanity is capable of causing through its actions to the life-giving air, we should think about further measures to preserve and restore the atmosphere.