Find the mass of the earth's atmosphere. The importance of the atmosphere for humans

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

Troposphere;
Stratosphere;
Mesosphere;
Thermosphere;
Exosphere.

Diagram of the main layers of the Earth's atmosphere

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

Troposphere: where weather occurs

Of all the layers of the atmosphere, the troposphere is the one with which we are most familiar (whether you realize it or not), since we live on its bottom - the surface of the planet. It envelops the surface of the Earth and extends upward for several kilometers. The word troposphere means "change of the globe." A very appropriate name, since this layer is where our everyday weather occurs.

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

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

Stratosphere: home of the ozone

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

Here the air does not flow up and down, but moves parallel to the surface in very fast air currents. As you rise, the temperature increases, thanks to the abundance of naturally occurring ozone (O3), a byproduct of solar radiation and oxygen, which has the ability to absorb the sun's harmful ultraviolet rays (any increase in temperature with altitude in meteorology is known as an "inversion") .

Because the stratosphere has warmer temperatures at the bottom and cooler temperatures at the top, convection (vertical movement of air masses) is rare in this part of the atmosphere. In fact, you can view a storm raging in the troposphere from the stratosphere because the layer acts as a convection cap that prevents storm clouds from penetrating.

After the stratosphere there is again a buffer layer, this time called the stratopause.

Mesosphere: middle atmosphere

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

Thermosphere: upper atmosphere

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

Exosphere: the boundary between the atmosphere and space

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

What about the ionosphere?

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

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 all 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 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 density of gases 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

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.

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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The atmosphere is the gaseous shell of our planet, which rotates along with the Earth. The gas in the atmosphere is called air. The atmosphere is in contact with the hydrosphere and partially covers the lithosphere. But the upper limits are difficult to determine. It is conventionally accepted that the atmosphere extends upward for approximately three thousand kilometers. There it smoothly flows into airless space.

Chemical composition of the Earth's atmosphere

The formation of the chemical composition of the atmosphere began about four billion years ago. Initially, the atmosphere consisted only of light gases - helium and hydrogen. According to scientists, the initial prerequisites for the creation of a gas shell around the Earth were volcanic eruptions, which, along with lava, emitted huge amounts of gases. Subsequently, gas exchange began with water spaces, with living organisms, and with the products of their activities. The composition of the air gradually changed and was fixed in its modern form several million years ago.

The main components of the atmosphere are nitrogen (about 79%) and oxygen (20%). The remaining percentage (1%) is made up of the following gases: argon, neon, helium, methane, carbon dioxide, hydrogen, krypton, xenon, ozone, ammonia, sulfur and nitrogen dioxides, nitrous oxide and carbon monoxide, which are included in this one percent.

In addition, the air contains water vapor and particulate matter (pollen, dust, salt crystals, aerosol impurities).

Recently, scientists have noted not a qualitative, but a quantitative change in some air ingredients. And the reason for this is man and his activities. In the last 100 years alone, carbon dioxide levels have increased significantly! This is fraught with many problems, the most global of which is climate change.

Formation of weather and climate

The atmosphere plays a critical role in shaping the climate and weather on Earth. A lot depends on the amount of sunlight, the nature of the underlying surface and atmospheric circulation.

Let's look at the factors in order.

1. The atmosphere transmits the heat of the sun's rays and absorbs harmful radiation. The ancient Greeks knew that the rays of the Sun fall on different parts of the Earth at different angles. The word “climate” itself translated from ancient Greek means “slope”. So, at the equator, the sun's rays fall almost vertically, which is why it is very hot here. The closer to the poles, the greater the angle of inclination. And the temperature drops.

2. Due to the uneven heating of the Earth, air currents are formed in the atmosphere. They are classified according to their sizes. The smallest (tens and hundreds of meters) are local winds. This is followed by monsoons and trade winds, cyclones and anticyclones, and planetary frontal zones.

All these air masses are constantly moving. Some of them are quite static. For example, trade winds that blow from the subtropics towards the equator. The movement of others depends largely on atmospheric pressure.

3. Atmospheric pressure is another factor influencing climate formation. This is the air pressure on the surface of the earth. As is known, air masses move from an area with high atmospheric pressure towards an area where this pressure is lower.

A total of 7 zones are allocated. The equator is a low pressure zone. Further, on both sides of the equator up to the thirties latitudes there is an area of high pressure. From 30° to 60° - low pressure again. And from 60° to the poles is a high pressure zone. Air masses circulate between these zones. Those that come from the sea to land bring rain and bad weather, and those that blow from the continents bring clear and dry weather. In places where air currents collide, atmospheric front zones are formed, which are characterized by precipitation and inclement, windy weather.

Scientists have proven that even a person’s well-being depends on atmospheric pressure. According to international standards, normal atmospheric pressure is 760 mm Hg. column at a temperature of 0°C. This indicator is calculated for those areas of land that are almost level with sea level. With altitude the pressure decreases. Therefore, for example, for St. Petersburg 760 mm Hg. - this is the norm. But for Moscow, which is located higher, normal pressure is 748 mm Hg.

The pressure changes not only vertically, but also horizontally. This is especially felt during the passage of cyclones.

The structure of the atmosphere

The atmosphere is reminiscent of a layer cake. And each layer has its own characteristics.

. Troposphere- the layer closest to the Earth. The "thickness" of this layer changes with distance from the equator. Above the equator, the layer extends upward by 16-18 km, in temperate zones by 10-12 km, at the poles by 8-10 km.

It is here that 80% of the total air mass and 90% of water vapor are contained. Clouds form here, cyclones and anticyclones arise. The air temperature depends on the altitude of the area. On average, it decreases by 0.65° C for every 100 meters.

. Tropopause- transition layer of the atmosphere. Its height ranges from several hundred meters to 1-2 km. The air temperature in summer is higher than in winter. For example, above the poles in winter it is -65° C. And above the equator it is -70° C at any time of the year.

. Stratosphere- this is a layer whose upper boundary lies at an altitude of 50-55 kilometers. Turbulence here is low, the content of water vapor in the air is negligible. But there is a lot of ozone. Its maximum concentration is at an altitude of 20-25 km. In the stratosphere, the air temperature begins to rise and reaches +0.8° C. This is due to the fact that the ozone layer interacts with ultraviolet radiation.

. Stratopause- a low intermediate layer between the stratosphere and the mesosphere that follows it.

. Mesosphere- the upper boundary of this layer is 80-85 kilometers. Complex photochemical processes involving free radicals occur here. They are the ones who provide that gentle blue glow of our planet, which is seen from space.

Most comets and meteorites burn up in the mesosphere.

. Mesopause- the next intermediate layer, the air temperature in which is at least -90°.

. Thermosphere- the lower boundary begins at an altitude of 80 - 90 km, and the upper boundary of the layer runs approximately at 800 km. The air temperature is rising. It can vary from +500° C to +1000° C. During the day, temperature fluctuations amount to hundreds of degrees! But the air here is so rarefied that understanding the term “temperature” as we imagine it is not appropriate here.

. Ionosphere- combines the mesosphere, mesopause and thermosphere. The air here consists mainly of oxygen and nitrogen molecules, as well as quasi-neutral plasma. The sun's rays entering the ionosphere strongly ionize air molecules. In the lower layer (up to 90 km) the degree of ionization is low. The higher, the greater the ionization. So, at an altitude of 100-110 km, electrons are concentrated. This helps to reflect short and medium radio waves.

The most important layer of the ionosphere is the upper one, which is located at an altitude of 150-400 km. Its peculiarity is that it reflects radio waves, and this facilitates the transmission of radio signals over considerable distances.

It is in the ionosphere that such a phenomenon as the aurora occurs.

. Exosphere- consists of oxygen, helium and hydrogen atoms. The gas in this layer is very rarefied and hydrogen atoms often escape into outer space. Therefore, this layer is called the “dispersion zone”.

The first scientist to suggest that our atmosphere has weight was the Italian E. Torricelli. Ostap Bender, for example, in his novel “The Golden Calf” lamented that every person is pressed by a column of air weighing 14 kg! But the great schemer was a little mistaken. An adult experiences pressure of 13-15 tons! But we do not feel this heaviness, because atmospheric pressure is balanced by the internal pressure of a person. The weight of our atmosphere is 5,300,000,000,000,000 tons. The figure is colossal, although it is only a millionth of the weight of our planet.

Troposphere

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

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

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, 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, 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

Since the existence of life, the comfort and safety of all organisms depends on it. The indicators of gases in the mixture are decisive for the study of problem areas or environmentally favorable areas.

General information

The term “atmosphere” refers to the layer of gas that envelops our planet and many other celestial bodies in the Universe. It forms a shell that rises several hundred kilometers above the Earth. The composition contains a variety of gases, the main of which is oxygen.

The atmosphere is characterized by:

Heterogeneity from a physical point of view.
Increased dynamism.
Dependence on biological factors (high vulnerability in case of adverse events).

The main influence on the composition and processes that change it are living beings (including microorganisms). These processes have been going on since the formation of the atmosphere – several billion years. The protective shell of the planet is in contact with formations such as the lithosphere and hydrosphere, but the upper boundaries are difficult to determine with high accuracy; scientists can only give approximate values. The atmosphere passes into interplanetary space in the exosphere - at altitude
500-1000 km from the surface of our planet, some sources call the figure 3000 km.

The importance of the atmosphere for life on earth is great, since it protects the planet from collisions with cosmic bodies and provides optimal indicators for the formation and development of life in its various forms.
Composition of the protective shell:

Nitrogen – 78%.
Oxygen – 20.9%.
Gas mixture – 1.1% (this part is formed by substances such as ozone, argon, neon, helium, methane, krypton, hydrogen, xenon, carbon dioxide, water vapor).

The gas mixture performs an important function - absorbing excess solar energy. The composition of the atmosphere varies depending on altitude - at an altitude of 65 km from the Earth's surface it will contain nitrogen
already 86%, oxygen – only 19%.

Components of the atmosphere

The diverse composition of the Earth's atmosphere allows it to perform various functions and protect life on the planet. Its main elements:

Carbon dioxide (CO₂) is an integral component involved in the process of plant nutrition (photosynthesis). It is released into the atmosphere due to the respiration of all living organisms, decay and combustion of organic substances. If carbon dioxide disappears, then plants will cease to exist along with it.
Oxygen (O₂) – provides an optimal environment for the life of all organisms on the planet and is required for respiration. With its disappearance, life will cease for 99% of organisms on the planet.
Ozone (O 3) is a gas that acts as a natural absorber of ultraviolet radiation emitted by solar radiation. Its excess negatively affects living organisms. The gas forms a special layer in the atmosphere - the ozone shield. Under the influence of external conditions and human activities, it begins to gradually deteriorate, so it is important to take measures to restore the ozone layer of our planet in order to preserve life on it.

The atmosphere also contains water vapor - they determine the humidity of the air. The percentage of this component depends on various factors. Influenced by:

Air temperature indicators.
Location of the area (territory).
Seasonality.

It affects the amount of water vapor and temperature - if it is low, then the concentration does not exceed 1%, if it is elevated, it reaches 3-4%.
Additionally, the earth's atmosphere contains solid and liquid impurities - soot, ash, sea salt, various microorganisms, dust, water droplets.

Atmosphere: its layers

It is necessary to know the structure of the earth's atmosphere in layers in order to have a complete understanding of why this gaseous shell is valuable to us. They stand out because the composition and density of the gas mixture at different altitudes is not the same. Each layer differs in chemical composition and functions. The atmospheric layers of the earth should be arranged in order as follows:

The troposphere is located closest to the earth's surface. The heights of this layer reach 16-18 km in tropical zones and 9 km on average above the poles. Up to 90% of all water vapor is concentrated in this layer. It is in the troposphere that the process of cloud formation occurs. Air movement, turbulence and convection are also observed here. Temperatures vary and range from +45 to -65 degrees - in the tropics and at the poles, respectively. With an increase of 100 meters, the temperature decreases by 0.6 degrees. It is the troposphere, due to the accumulation of water vapor and air, that is responsible for cyclonic processes. Accordingly, the correct answer to the question of what is the name of the layer of the earth’s atmosphere in which cyclones and anticyclones develop will be the name of this atmospheric layer.

Stratosphere - this layer is located at an altitude of 11-50 km from the surface of the planet. In its lower zone, temperatures tend to reach values of -55. In the stratosphere there is an inversion zone - the boundary between this layer and the next one, called the mesosphere. Temperatures reach values of +1 degree. Airplanes fly in the lower stratosphere.

The ozone layer is a small area on the border between the stratosphere and mesosphere, but it is the ozone layer of the atmosphere that protects all life on earth from the effects of ultraviolet radiation. He also distinguishes between comfortable and favorable conditions for the existence of living organisms and harsh space ones, where it is impossible for even bacteria to survive without special conditions. It was formed as a result of the interaction of organic components and oxygen, which comes into contact with ultraviolet radiation and enters into a photochemical reaction, which produces a gas called ozone. Since ozone absorbs ultraviolet radiation, it warms the atmosphere, maintaining optimal conditions for life in its usual form. Accordingly, ozone should answer the question: what gas layer protects the earth from cosmic radiation and excessive solar radiation?

Considering the layers of the atmosphere in order from the surface of the earth, it should be noted that the mesosphere comes next. It is located at an altitude of 50-90 km from the surface of the planet. Temperature indicators – from 0 to -143 degrees (lower and upper limits). It protects the Earth from meteorites that burn up when passing through
it is the phenomenon of air glow. The gas pressure in this part of the atmosphere is extremely low, which makes it impossible to study the mesosphere completely, since special equipment, including satellites or probes, cannot work there.

The thermosphere is a layer of the atmosphere that is located at an altitude of 100 km above sea level. This is the lower limit, which is called the Karman line. Scientists have conditionally determined that space begins here. The immediate thickness of the thermosphere reaches 800 km. Temperatures reach 1800 degrees, but a slight concentration of air allows the skin of spacecraft and rockets to be kept intact. In this layer of the earth's atmosphere a special
phenomenon - the northern lights - a special type of glow that can be observed in some regions of the planet. They appear as a result of the interaction of several factors - ionization of the air and the effect of cosmic radiation and radiation on it.

Which layer of the atmosphere is furthest from the earth - the Exosphere. There is an air dispersion zone here, since the concentration of gases is low, as a result of which they gradually escape beyond the atmosphere. This layer is located at an altitude of 700 km above the Earth's surface. The main element that makes up
This layer is hydrogen. In the atomic state, you can find substances such as oxygen or nitrogen, which will be highly ionized by solar radiation.
The dimensions of the Earth's exosphere reach 100 thousand km from the planet.

By studying the layers of the atmosphere in order from the surface of the earth, people have received a lot of valuable information that helps in the development and improvement of technological capabilities. Some facts are surprising, but it was their presence that allowed living organisms to develop successfully.

It is known that the weight of the atmosphere is more than 5 quadrillion tons. The layers are capable of transmitting sounds up to 100 km from the surface of the planet; above this property disappears, as the composition of the gases changes.
Atmospheric movements exist because the Earth's heating varies. The surface at the poles is cold, and closer to the tropics the heating increases; temperature indicators are influenced by cyclonic eddies, seasons, and time of day. The strength of atmospheric pressure can be found out - a barometer is used for this purpose. As a result of observations, scientists have established that the presence of protective layers makes it possible to prevent meteorites with a total mass of 100 tons from contacting the surface of the planet every day.

An interesting fact is that the composition of the air (the mixture of gases in the layers) remained unchanged over a long period of time - several hundred million years are known. Significant changes have taken place in recent centuries - since humanity has experienced a significant increase in production.

The pressure exerted by the atmosphere affects people's well-being. Indicators of 760 mmHg are considered normal for 90%; this value should occur at 0 degrees. It must be taken into account that this value is valid for those areas of the earth’s land where the sea level lies in the same band with it (without drops). The higher the altitude, the lower the pressure will be. It also changes during the passage of cyclones, since changes occur not only vertically, but also horizontally.

The physiological zone of the earth's atmosphere is 5 km; after passing this mark, a person begins to experience a special condition - oxygen starvation. During this process, 95% of people experience a pronounced decrease in performance, and the well-being of even a prepared and trained person also deteriorates significantly.

That is why the atmosphere is so important for life on earth - people and most living organisms cannot exist without this gas mixture. Thanks to their presence, it became possible to develop the life on Earth familiar to modern society. It is necessary to assess the damage caused by industrial activities, carry out air purification measures in order to reduce the concentration of certain types of gases and introduce those that are not sufficient for normal composition. It is important to think now about further measures to preserve and restore layers of the atmosphere in order to maintain optimal conditions for future generations.