The upper part of the atmosphere, above the mesosphere, is characterized by very high temperatures and therefore is called the thermosphere. It differs, however, two parts: an ionosphere extending from the mesosphere to the height of about a thousand kilometers, and the outside of her exterior is an exosphere, turning into the earth's crown.
The air in the ionosphere is extremely resolved. We have already indicated that at the heights of 300-750 km its average density of about 10-8-10-10 g / m3. But even with such a small density, each cubic centimeter of air at an altitude of 300 km still contains about one billion (109) molecules or atoms, and at an altitude of 600 km - over 10 million (107). This is several orders of magnitude greater than the gas content in the interplanetary space.
The ionosphere, as the name itself says, is characterized by a very strong degree of air ionization - the content of ions here is many times more than in the underlying layers, despite the strong overall affairs of air. These ions are mainly charged oxygen atoms charged with nitrogen oxide molecules and free electrons. Their content at altitudes 100-400 km is about 1015-106 per cubic centimeter.
In the ionosphere, several layers are distinguished, or regions, with maximum ionization, especially at altitudes 100-120 km (layer E) and 200-400 km (layer F). But in the intervals between these layers, the degree of ionization of the atmosphere remains very high. The position of the ionospheric layers and the concentration of ions in them is changing all the time. Sporadic accumulations of electrons with a particularly large concentration are called electronic clouds.
The degree of ionization depends the electrical conductivity of the atmosphere. Therefore, in the ionosphere, the air conductor is generally 1012 times greater than that of the earth's surface. Radio waves are tested in the absorption, refraction and reflection ionosphere. Waves longer than 20 m long can not pass through the ionosphere: they are already reflected by the electronic layers of small concentration in the lower part of the ionosphere (at 70-80 km altitudes). Medium and short waves are reflected by the overlying ionospheric layers.
It is due to the reflection from the ionosphere, a long-range connection is possible on short waves. Multiple reflection from the ionosphere and the earth's surface allows short waves zigzago-like spreading over long distances, a ribous surface of the globe. Since the position and concentration of ionospheric layers are continuously changing, the conditions of absorption, reflection and distribution of radio waves are changed. Therefore, for reliable radio communications, it is necessary to continuously study the state of the ionosphere. Observations on the spread of radio waves are just a means of such a study.
The ionosphere observed polar radiances and the glow of the night sky close to them - the constant luminescence of atmospheric air, as well as sharp oscillations of the magnetic field - ionospheric magnetic storms.
Ionization in the ionosphere is obliged to its existence of the ultraviolet radiation of the Sun. Its absorption of atmospheric gas molecules leads to the occurrence of charged atoms and free electrons, as mentioned above. The oscillations of the magnetic field in the ionosphere and polar radiance depend on the fluctuations of solar activity. Changes in solar activity are associated with changes in the flow of corpuscular radiation, which comes from the Sun to the earth's atmosphere. Namely, corpuscular radiation has a basic value for these ionospheric phenomena.
The temperature in the ionosphere grows with a height to very large values. At altitudes about 800 km, it reaches 1000 °.
Speaking of high temperatures of the ionosphere, they mean that particles of atmospheric gases are moving there with very large speeds. However, the density of air in the ionosphere is so small that the body located in the ionosphere, for example, a flying satellite will not be heated by heat exchange with air. The temperature regime of the satellite will depend on the immediate absorption of solar radiation and on the recoil of its own radiation into the surrounding space. The thermosphere is above the mesosphere at a height of 90 to 500 km above the surface of the Earth. Gas molecules here are strongly scattered, the X-ray radiation is absorbed (x Rays) and the short-wave part of the ultraviolet radiation. Because of this, the temperature can reach 1000 degrees Celsius.
the thermosphere mainly corresponds to the ionosphere, where ionized gas reflects radio waves back to Earth - this phenomenon gives it possible to install radio communication.
The atmosphere has clearly pronounced air layers. Air layers are different between themselves the temperature, the difference between gases and their density and pressure. It should be noted that the stratosphere layers and the troposphere protect the Earth from solar radiation. In the higher layers, a living organism can get a deadly dose of ultraviolet solar spectrum. To quickly transition to the desired layer of the atmosphere, press the corresponding layer:
Troposphere and Tropopausa
Troposphere - Temperature, Pressure, Height
The upper border holds at 8 - 10 km about. In moderate latitudes 16 - 18 km, and in the polar 10 - 12 km. Troposphere - This is the lower main layer of the atmosphere. In this layer there is more than 80% of the entire mass of atmospheric air and close 90% of the entire water vapor. It is in the troposphere that convection and turbulence arise, clouds are formed, cyclones occur. Temperature Falls with height growth. Gradient: 0.65 ° / 100 m. Heated ground and water heat the attached air. Heated air rises to the top, cooled and forms clouds. The temperature in the upper boundaries of the layer can reach - 50/70 ° C.
It is in this layer that there are changes in climatic weather conditions. In the lower border of the troposphere called originnySince it has many volatile microorganisms and dust. Wind speed increases with increasing height in this layer.
Tropopausa
This is a transition layer of the troposphere to the stratosphere. Here, the dependence of the temperature reduction with an increase in height is terminated. The tropopause is a minimum height where the vertical temperature gradient drops to 0.2 ° C / 100 m. The height of the tropopause depends on the strong climatic manifestations, such as cyclones. Over cyclones, the height of the tropopause decreases, and over the anticyclones increases.
Stratosphere and Stratoauusa
The height of the stratosphere layer is approximately 11 to 50 km. There is a slight change in temperature at an altitude of 11 - 25 km. At an altitude of 25 - 40 km observed inversion Temperatures, from 56.5 rises to 0.8 ° C. From 40 km to 55, the temperature is kept at 0 ° C. This area is called - Stratoauzova.
The stratosphere observes the effect of solar radiation on the gas molecules, they dissociate to atoms. There is no water vapor in this layer. Modern supersonic commercial aircraft fly at an altitude of up to 20 km due to stable flight conditions. High-altitude meteosonds rise to a height of 40 km. Here are resistant air flows, the speed of them reaches 300 km / h. Also in this layer focused ozone, a layer that absorbs ultraviolet rays.
Mesosphere and Mesopause - Composition, Reaction, Temperature
The mesosphere layer begins approximately 50 km altitude and ends at 80 - 90 km. Temperatures decreases with an increase in the height of approximately 0.25-0.3 ° C / 100 m. The main energy action here is radiant heat exchange. Complex photochemical processes with the participation of free radicals (has 1 or 2 unpaired electronic). They are implemented glow Atmosphere.
Almost all meteors burn in the mesosphere. Scientists called this zone - Ignorosphere. It is hard to explore this zone, since the aerodynamic aviation is very bad here due to the density of the air, which is 1000 times less than on Earth. And to launch artificial satellites, the density is still very high. Studies are carried out with meteorological missiles, but this is a perversion. Mesopause The transition layer between the mesosphere and a thermosphere. It has a temperature of minimum -90 ° C.
Pickline line
Line Pocket Call the border between the atmosphere of the Earth and the Space. According to the international aviation federation (FAI), the height of this border is 100 km. Such definitions were given in honor of the American scientist theodore background pocket. It determined that at about this height, the atmosphere density was so small that the aerodynamic aviation here becomes impossible, since the speed of the aircraft must be more first cosmic velocity. At such an altitude, the concept of sound barrier loses its meaning. Here you can manage the aircraft only at the expense of jet forces.
Thermosphere and thermopause
The upper bound of this layer is about 800 km. The temperature grows in about the height of 300 km where it reaches about 1500 K. above the temperature remains unchanged. This layer happens polar Lights - It occurs as a result of the effects of solar radiation on air. Also, this process is called atmospheric oxygen ionization.
Because of the low room discharge, the flights above the pocket line are realizable only in ballistic pathistic paths. All manned orbital flights (except flights on the moon) occur in this layer of the atmosphere.
Ecosphere - Density, Temperature, Height
The height of the exosphere is higher than 700 km. Here the gas is strongly cleaned, and the process occurs dissipation - leakage of particles in the interplanetary space. The speed of such particles can reach 11.2 km / s. The growth of solar activity leads to the expansion of the thickness of this layer.
- A gas shell does not fly into space due to earthly attraction. Air consists of particles that have their own mass. From the law of gravity, it is possible to bear that each object possessing the mass is attracted to the Earth.
- The law of the buys-ballot states that if you are in the northern hemisphere and stand back to the wind, the high pressure zone will be located on the right, and the left is low. In the southern hemisphere, everything will be the opposite.
Flights in a thermosphere
Due to the extreme rareness of air, the flights above the pocket line are possible only by ballistic trajectories. All manned orbital flights (except flights to the moon) pass in a thermosphere, mainly at altitudes from 200 to 500 km - below 200 km strongly affects the braking air effect, and the radiation belts that have a harmful effect on people are extended.
The unmanned satellites are also for the most part in the thermosphere - the satellite output to a higher orbit requires high energy costs, moreover, for many purposes (for example, for remote sensing of the Earth), a small height is preferable.
The high air temperature in the thermosphere is not scary of aircraft, because due to the strong air rareness, it practically does not interact with the covering of the aircraft, that is, the air density is not enough to heat the physical body, since the number of molecules is very little and the frequency of their collisions with The trimming of the vessel (respectively and the transmission of thermal energy) is small.
Their studies are also conducted using
The gas shell surrounding our planet Earth, known as the atmosphere, consists of five main layers. These layers originate on the surface of the planet, from the sea level (sometimes lower) and rose to the outer space in the following sequence:
- Troposphere;
- Stratosphere;
- Mesosphere;
- Thermosphere;
- Exosphere.
Scheme of the main layers of the atmosphere of the Earth
In the interval between each of these major five layers there are transitional zones, called "pauses", where changes in temperature, composition and air density occur. Together with pauses, the Earth's atmosphere in total includes 9 layers.
Troprosphere: Where is the weather
Of all the layers of the atmosphere of the Troposphere is the one with which we are most familiar (whether you are aware or not), since we live at her day - the surface of the planet. It envelops the surface of the earth and stretches up a few kilometers. The word troposphere means "ball change". Very suitable name, as this layer, where our casual weather happens.
Starting from the surface of the planet, the troposphere rises to a height from 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 heats up the earth's surface absorbing the thermal energy of the Sun, with increasing height, the temperature and pressure of the troposphere are reduced.
At the top there is a thin layer, called a tropopause, which is only a buffer between the troposphere and the stratosphere.
Stratosphere: Ozone House
Stratosphere - the next layer of the atmosphere. It extends from 6-20 km to 50 km above the earth's ground. This is a layer in which most commercial airliners fly and travel balloons.
Here the air does not flow up and down, but is moving parallel to the surface in very fast air flows. As you rise, the temperature increases, due to the abundance of natural ozone (O 3) - by the side product of solar radiation and oxygen, which has the ability to absorb the harmful ultraviolet rays of the sun (any increase in temperature with a height of meteorology, is known as "inversion") .
Since the stratosphere has warmer temperatures below and cooler at the top, convection (vertical movement of air mass) occurs rarely in this part of the atmosphere. In fact, you can consider from the stratosphere raging in the storm troposphere, since the layer acts as a "cap" for convection, through which the storm clouds do not penetrate.
After the stratosphere again follows the buffer layer, this time called stratoatuise.
Mesosphere: average atmosphere
The mesosphere is approximately 50-80 km from the ground surface. The upper area of \u200b\u200bthe mesosphere is the coldest natural place on the ground, where the temperature can fall below -143 ° C.
Thermosphere: upper atmosphere
After the mesosphere and mesopause, there should be a 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 shell. Temperatures here achieve up to + 2000 ° C, but due to a strong air affection and lack of gas molecules for heat transfer, these high temperatures are perceived as very cold.
Ecosphere: The Border of the Atmosphere and Space
At an altitude of about 700-100 km above the earth's surface there is an exosphere - the outer edge of the atmosphere, bordering space. Here the meteorological satellites rotate around the Earth.
What about the ionosphere?
The ionosphere is not a separate layer, and in fact this term is used to designate the atmosphere at a height of 60 to 1000 km. It includes the topmost parts of the mesosphere, the entire thermosphere and part of the exosphere. The ionosphere got its name, because in this part of the atmosphere, the radiation of the Sun is ionized when the magnetic fields of the Earth on and. This phenomena is observed from the Earth as the Northern Lights.
Everyone who flew by plane was accustomed to the report of this kind: "Our flight is taking place at an altitude of 10,000 m, the temperature overboard - 50 ° C." It seems nothing special. The farther from the earth heated by the sun, the colder. Many people think that a decrease in temperature with a height is continuously and gradually the temperature drops, approaching the temperature of the space. By the way, scientists thought so until the end of the 19th century.
We will deal with more details with the distribution of air temperature over the ground. The atmosphere is divided into several layers, which reflect primarily the nature of temperature change.
The bottom layer of the atmosphere is called Triposfer, which means "sphere of rotation". All changes of weather and climate are the result of the physical processes occurring in this layer. The upper limit of this layer is located where the decrease in temperature with a height is replaced by its increase, - approximately at a height of 15-16 km above the equator and 7-8 km over the poles. Like the Earth itself, the atmosphere under the influence of the rotation of our planet is also somewhat flattened over the poles and swells over the equator. However, this effect is expressed in the atmosphere much stronger than in the solid sheath of the Earth. In the direction of the earth's surface The upper boundary of the troposphere. The air temperature drops. Above the equator The minimum air temperature is about -62 ° C, and over the poles about -45 ° C. In moderate latitudes, more than 75% of the mass of the atmosphere is in the troposphere. In the tropics, about 90% is within the tropospherics Mass atmosphere.
In 1899, it was found in a vertical temperature profile at some height, and then the temperature increased slightly. The beginning of this increase means the transition to the next layer of the atmosphere - to StratosphereWhat means "Layer Sphere". The term stratosphere means and reflects the previous idea of \u200b\u200bthe uniqueness of the layer underlying the troposphere. Stratosphere extends to a height of about 50 km above the earth's surface. A feature is, in particular, a sharp increase in air temperature. This temperature increases explain The reaction of ozone formation is one of the main chemical reactions occurring in the atmosphere.
The bulk of ozone is concentrated at altitudes about 25 km, but in general, the ozone layer is a strongly stretched in height of the shell, covering almost the entire stratosphere. The interaction of oxygen with ultraviolet rays is one of the favorable processes in the earth's atmosphere, contributing to the maintenance of life on Earth. Absorption by the ozone of this energy prevents it in excessive flow to the earth's surface, where such an energy level is created that is suitable for the existence of earthly forms of life. Ozoneosphere absorbs part of radiant energy passing through the atmosphere. As a result, a vertical air temperature gradient is set to about 0.62 ° C per 100 m in the ozoneosphere per 100 m, that is, the temperature rises with a height up to the upper limit of the stratosphere - stratopause (50 km), reaching, according to some data, 0 ° C.
At the heights of 50 to 80 km, there is a layer of atmosphere, called Mesosphere. The word "mesosphere" means "intermediate sphere", here the temperature of the air continues to decrease with a height. Above the mesosphere, in the layer called ThermosphereThe temperature rises again with a height of about 1000 ° C, and then it drops very quickly to -96 ° C. However, it is not impossible to fall, then the temperature increases again.
Thermosphere is the first layer ionosphere. In contrast to the previously mentioned layers, the ionosphere is not highlighted by a temperature trait. The ionosphere is an area having an electric nature due to which many types of radio communications become possible. The ionosphere is divided into several layers, denoting them with letters D, E, F1 and F2 these layers also have special names. The separation into layers is caused by several reasons, among which the most important and unequal influence of layers on the passage of radio waves. The lowest layer, D, mainly absorbs radio waves and thereby prevents their further distribution. The well-studied layer E is located at an altitude of about 100 km above the ground surface. He is also called the layer of Kennelli - Hebiside on the names of American and English scientists, which at the same time and independently discovered it. Layer E, like a giant mirror, reflects radio waves. Thanks to this layer, long radio waves pass more distant distances than it should be expected if they spread only straightforwardly, without reflecting the layer of E. Similar properties and layer F. It is also called the Epplton layer. Together with the kennelly heviside layer, it reflects radio wave to ground radio stations such a reflection can occur at different angles. The Epplton layer is located at an altitude of about 240 km.
The most external area of \u200b\u200bthe atmosphere, the second layer of the ionosphere, is often called Exosphere. This term indicates the existence of the outskirts of the cosmos near the ground. To determine where the atmosphere is ends and the space begins, it is difficult, since with a height of atmospheric gas density decreases gradually and the atmosphere itself becomes smoothly in almost a vacuum, in which only individual molecules are found. Already at an altitude of approximately 320 km, the atmosphere density is so small that molecules, without facing each other, can go through the path of more than 1 km. The most outer part of the atmosphere serves as it would be its upper boundary, which is located at altitudes from 480 to 960 km.
Read more about the processes and the atmosphere can be found on the site "Earth Climate"
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