Mesosphere
Stratosphere
Above the troposphere is the stratosphere (from the Greek "stratium" - flooring, layer). Its mass is 20% of the mass of the atmosphere.
The upper boundary of the stratosphere is located from the Earth's surface at a height of:
In tropical latitudes (equator) 50 - 55 km .:
In temperate latitudes up to 50 km.;
In polar latitudes (poles) 40 - 50 km.
In the stratosphere, the air heats up as it rises, while the air temperature rises with height by an average of 1–2 degrees per 1 km. rise and reaches up to +50 0 C at the upper limit.
The increase in temperature with height is mainly due to ozone, which absorbs the ultraviolet part of solar radiation. At an altitude of 20 - 25 km from the Earth's surface, there is a very thin (only a few centimeters) ozone layer.
The stratosphere is very poor in water vapor, there is no precipitation here, although sometimes at an altitude of 30 km. clouds are formed.
Based on observations in the stratosphere, turbulent disturbances and strong winds blowing in different directions have been established. As in the troposphere, powerful air vortices are noted, which are especially dangerous for high-speed aircraft.
strong winds called jet streams blow in narrow zones along the borders of temperate latitudes facing the poles. However, these zones can shift, disappear and reappear. Jet streams usually penetrate the tropopause and appear in the upper troposphere, but their speed decreases rapidly with decreasing altitude.
It is possible that part of the energy entering the stratosphere (mainly spent on the formation of ozone) is associated with atmospheric fronts, where extensive flows of stratospheric air have been recorded significantly below the tropopause, and tropospheric air is drawn into the lower layers of the stratosphere.
Above the stratopause is the mesosphere (from the Greek "mesos" - middle).
The upper boundary of the mesosphere is located at a height from the Earth's surface:
In tropical latitudes (equator) 80 - 85 km .;
In temperate latitudes up to 80 km .;
In polar latitudes (poles) 70 - 80 km.
In the mesosphere, the temperature drops to -60 0 C. - 1000 0 C. at its upper boundary.
In the polar regions in summer, cloud systems often appear in the mesopause, which occupy a large area, but have little vertical development. Such clouds glowing at night often make it possible to detect large-scale undulating air movements in the mesosphere. The composition of these clouds, sources of moisture and condensation nuclei, dynamics and relationship with meteorological factors are still insufficiently studied.
Above the mesopause is the thermosphere (from the Greek "thermos" - warm).
The upper boundary of the thermosphere is located at a height from the Earth's surface:
In tropical latitudes (equator) up to 800 km;
In temperate latitudes up to 700 km .;
In polar latitudes (poles) up to 650 km.
In the thermosphere, the temperature rises again, reaching 2000 0 C in the upper layers.
It should be noted that the altitudes of 400 - 500 km. and above, the air temperature cannot be determined by any of the known methods, due to the extreme rarefaction of the atmosphere. The air temperature at such altitudes has to be judged from the energy of gas particles moving in gas streams.
The increase in air temperature in the thermosphere is associated with the absorption of ultraviolet radiation and the formation of ions and electrons in atoms and molecules of gases contained in the atmosphere.
In the thermosphere, the pressure and, consequently, the density of the gas gradually decreases with height. In the vicinity of the earth's surface in 1 m 3. air contains about 2.5x10 25 molecules, at an altitude of about 100 km in the lower layers of the thermosphere 1 m 3 of air contains about 2.5x10 25 molecules. At an altitude of 200 km., In the ionosphere at 1 m 3. air contains 5x10 15 molecules. At an altitude of about 850 km. in 1m. air contains 10 12 molecules. In interplanetary space, the concentration of molecules is 10 8 - 10 9 per 1 m 3 . At an altitude of about 100 km. the number of molecules is small, but they rarely collide with each other. The average distance traveled by a chaotically moving molecule before colliding with another similar molecule is called its mean free path.
At a certain temperature, the speed of a molecule's movement depends on its mass: lighter molecules move faster than heavier ones. In the lower atmosphere, where the free path is very short, there is no noticeable separation of gases according to their molecular weight, but it is expressed above 100 km. In addition, under the influence of ultraviolet and X-ray radiation from the Sun, oxygen molecules break up into atoms, the mass of which is half the mass of the molecule. Therefore, as one moves away from the Earth's surface, atmospheric oxygen becomes increasingly important in the composition of the atmosphere at an altitude of about 200 km. becomes the main ingredient.
Above, at a distance of approximately 1200 km. light gases helium and hydrogen dominate from the Earth's surface. They are the outer layer of the atmosphere.
This expansion by weight is called diffuse expansion, reminiscent of the separation of mixtures using a centrifuge.
Surprisingly, we have to return to this issue due to the fact that many people have no idea where the International "space" station actually flies and where the "cosmonauts" outer space or into the Earth's atmosphere.
This is a fundamental question - you understand? People are hammered into their heads that the representatives of humanity, who were given the proud definitions of "astronauts" and "cosmonauts", freely carry out spacewalks, and moreover, there is even a "Space" station flying in this supposedly "space". And all this at a time when all these "achievements" are being made in the earth's atmosphere.
All manned orbital flights take place in the thermosphere, mainly at altitudes from 200 to 500 km - below 200 km the decelerating effect of air is strongly affected, and above 500 km there are radiation belts that have a harmful effect on people.
Unmanned satellites also mostly fly in the thermosphere - putting a satellite into a higher orbit requires more energy, in addition, for many purposes (for example, for remote sensing of the Earth), low altitude is preferable.
The high air temperature in the thermosphere is not terrible for aircraft, because due to the strong rarefaction of air, it practically does not interact with the skin of the aircraft, that is, the air density is not enough to heat the physical body, since the number of molecules is very small and the frequency of their collisions with ship's hull (respectively, the transfer of thermal energy) is small. Thermosphere research is also carried out with the help of suborbital geophysical rockets. Auroras are observed in the thermosphere.
Thermosphere(from Greek θερμός - "warm" and σφαῖρα - "ball", "sphere") - atmospheric layer following the mesosphere. It starts at an altitude of 80-90 km and extends up to 800 km. The air temperature in the thermosphere fluctuates by different levels, increases rapidly and discontinuously and can vary from 200 K to 2000 K, depending on the degree of solar activity. The reason is the absorption of ultraviolet radiation from the Sun at altitudes of 150-300 km, due to the ionization of atmospheric oxygen. In the lower part of the thermosphere, the increase in temperature is largely due to the energy released during the combination (recombination) of oxygen atoms into molecules (in this case, the energy of solar UV radiation, previously absorbed during the dissociation of O2 molecules, is converted into the energy of thermal motion of particles). At high latitudes important source heat in the thermosphere - Joule heat released electric currents magnetospheric origin. This source causes significant but uneven heating of the upper atmosphere in subpolar latitudes, especially during magnetic storms.
outer space (space)- relatively empty regions of the universe that lie outside the boundaries of the atmospheres celestial bodies. Contrary to popular belief, space is not completely empty space - it has a very low density of some particles (mainly hydrogen), as well as electromagnetic radiation and interstellar matter. The word "cosmos" has several different meanings. Sometimes space is understood as all space outside the Earth, including celestial bodies.
400 km - height of the orbit of the International Space Station
500 km - the beginning of the inner proton radiation belt and the end of safe orbits for long-term human flights.
690 km - the boundary between the thermosphere and the exosphere.
1000-1100 km - the maximum height of the auroras, the last manifestation of the atmosphere visible from the Earth's surface (but usually well-marked auroras occur at altitudes of 90-400 km).
1372 km - the maximum height reached by man (Gemini 11 September 2, 1966).
2000 km - the atmosphere does not affect satellites and they can exist in orbit for many millennia.
3000 km - the maximum intensity of the proton flux of the inner radiation belt (up to 0.5-1 Gy/hour).
12,756 km - we moved away at a distance equal to the diameter of the planet Earth.
17,000 km - outer electronic radiation belt.
35 786 km - the height of the geostationary orbit, the satellite at this height will always hang over one point of the equator.
90,000 km - distance to the head shock wave formed by the collision of the Earth's magnetosphere with the solar wind.
100,000 km - the upper boundary of the exosphere (geocorona) of the Earth noticed by satellites. The atmosphere is over, open space and interplanetary space began.
So the news NASA astronauts fix cooling system during spacewalk ISS ", should sound different - " NASA astronauts during the exit into the Earth's atmosphere, repaired the cooling system ISS ", and the definitions of "astronauts", "cosmonauts" and "International Space station"require adjustments, for the simple reason that the station is not a space station and astronauts with astronauts, rather, atmospheric astronauts :)
From Wikipedia, the free encyclopedia
Flying in the thermosphere
Due to the extreme thinness of the air, flights above the Karman line are possible only along ballistic trajectories. All manned orbital flights (except flights to the Moon) take place in the thermosphere, mainly at altitudes from 200 to 500 km - below 200 km the decelerating effect of air is strongly affected, and radiation belts extend above 500 km, which have a harmful effect on people.
Unmanned satellites also mostly fly in the thermosphere - putting a satellite into a higher orbit requires more energy, in addition, for many purposes (for example, for remote sensing of the Earth), low altitude is preferable.
The high air temperature in the thermosphere is not terrible for aircraft, because due to the strong rarefaction of air, it practically does not interact with the skin of the aircraft, that is, the air density is not enough to heat the physical body, since the number of molecules is very small and the frequency of their collisions with ship's hull (respectively, the transfer of thermal energy) is small. Thermosphere research is also carried out with the help of suborbital geophysical rockets.
Write a review on the article "Thermosphere"An excerpt characterizing the Thermosphere“My God, if he were here; then I would not be like before, with some kind of stupid timidity in front of something, but in a new way, I would simply hug him, snuggle up to him, make him look at me with those searching, curious eyes with which he so often looked at me and then would make him laugh, as he laughed then, and his eyes - how I see those eyes! thought Natasha. - And what do I care about his father and sister: I love him alone, him, him, with this face and eyes, with his smile, masculine and childish at the same time ... No, it’s better not to think about him, not think, forget, completely forget for this time. I can’t bear this waiting, I’m about to sob,” and she moved away from the mirror, making an effort not to cry. “And how can Sonya love Nikolinka so evenly, so calmly, and wait so long and patiently!” she thought, looking at Sonya, also dressed, who came in, with a fan in her hands.“No, she is completely different. I can't"! Natasha felt at that moment so softened and tender that it was not enough for her to love and know that she was loved: she needed now, now she needed to hug her beloved and speak and hear from him words of love with which her heart was full. While she was riding in the carriage, sitting next to her father, and gazing thoughtfully at the lights of the lanterns flickering in the frozen window, she felt even more in love and sadder and forgot with whom and where she was going. Having fallen into a line of carriages, the Rostovs' carriage, slowly screeching through the snow, drove up to the theater. Natasha and Sonya hurriedly jumped out, picking up dresses; the count came out, supported by lackeys, and between the ladies and men entering and selling posters, all three went into the corridor of the benoir. The sounds of music could be heard from behind the closed doors. - Nathalie, vos cheveux, [Natalie, your hair,] - whispered Sonya. The chaplain politely and hurriedly slipped in front of the ladies and opened the door of the box. The music became louder heard at the door, the illuminated rows of boxes with the bare shoulders and arms of the ladies, and the parterre noisy and shiny with uniforms, flashed. The lady, entering the neighboring bin, looked around Natasha with a feminine, envious look. The curtain had not yet risen and the overture was being played. Natasha, straightening her dress, walked along with Sonya and sat down, looking around the illuminated rows of opposite boxes. She had not experienced for a long time the feeling that hundreds of eyes were looking at her bare arms and neck, suddenly and pleasantly and unpleasantly seized her, causing a whole swarm of memories, desires and worries corresponding to this sensation. Two remarkably pretty girls, Natasha and Sonya, with Count Ilya Andreich, who had not been seen in Moscow for a long time, attracted everyone's attention. In addition, everyone knew vaguely about Natasha's conspiracy with Prince Andrei, knew that since then the Rostovs had lived in the village, and looked with curiosity at the bride of one of the best grooms in Russia. |
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. In the troposphere, turbulence and convection are highly developed, clouds appear, cyclones and anticyclones develop. Temperature decreases with altitude with an average vertical gradient of 0.65°/100 m
tropopause
The transitional layer from the troposphere to the stratosphere, the layer of the atmosphere in which the decrease in temperature with height stops.
Stratosphere
The layer of the atmosphere located at an altitude of 11 to 50 km. A slight change in temperature in the 11-25 km layer (the lower layer of the stratosphere) and its increase in the 25-40 km layer from -56.5 to 0.8 °C (the upper stratosphere layer or inversion region) are typical. Having reached a value of about 273 K (almost 0 °C) at an altitude of about 40 km, the temperature remains constant up to an altitude of about 55 km. This region of constant temperature is called the stratopause and is the boundary between the stratosphere and the mesosphere.
Stratopause
The boundary layer of the atmosphere between the stratosphere and the mesosphere. There is a maximum in the vertical temperature distribution (about 0 °C).
Mesosphere
The mesosphere begins at an altitude of 50 km and extends up to 80-90 km. The 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 mesosphere and thermosphere. There is a minimum in the vertical temperature distribution (about -90 °C).
Karman Line
Altitude above sea level, which is conventionally accepted as the boundary between the Earth's atmosphere and space. The Karmana line is located at an altitude of 100 km above sea level.
Earth's atmosphere boundary
Thermosphere
The upper limit is about 800 km. The temperature rises to altitudes of 200-300 km, where it reaches values of the order of 1500 K, after which it remains almost constant up to high altitudes. Under the influence of ultraviolet and x-ray solar radiation and cosmic radiation, air is ionized (“polar lights”) - the main regions of the ionosphere lie inside the thermosphere. At altitudes above 300 km, atomic oxygen predominates. The upper limit of the thermosphere is largely determined by the current activity of the Sun. During periods of low activity, there is a noticeable decrease in the size of this layer.
Thermopause
The region of the atmosphere above the thermosphere. In this region, the absorption of solar radiation is insignificant and the temperature does not actually change with height.
Exosphere (scattering sphere)
Atmospheric layers up to a height of 120 km
Exosphere - scattering zone, the outer part of the thermosphere, located above 700 km. The gas in the exosphere is very rarefied, and hence its particles leak into interplanetary space (dissipation).
Up to a height of 100 km, the atmosphere is a homogeneous, well-mixed mixture of gases. In higher layers, the distribution of gases in height depends on their molecular weights, the concentration of heavier gases decreases faster with distance from the Earth's surface. Due to the decrease in gas density, the temperature drops from 0 °C in the stratosphere to −110 °C in the mesosphere. However kinetic energy 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 are observed in time and space.
At an altitude of about 2000-3500 km, the exosphere gradually passes into the so-called near space vacuum, which is filled with highly rarefied particles of interplanetary gas, mainly hydrogen atoms. But this gas is only part of the interplanetary matter. The other part is composed of dust-like particles of cometary and meteoric origin. In addition to extremely rarefied dust-like particles, electromagnetic and corpuscular radiation of solar and galactic origin penetrates into this space.
The troposphere accounts for about 80% of the mass of the atmosphere, the stratosphere accounts for about 20%; the mass of the mesosphere is no more than 0.3%, the thermosphere is less than 0.05% of the total mass of the atmosphere. Based on the electrical properties in the atmosphere, the neutrosphere and ionosphere are distinguished. It is currently believed that the atmosphere extends to an altitude of 2000-3000 km.
Depending on the composition of the gas in the atmosphere, homosphere and heterosphere are distinguished. The heterosphere is an area where gravity has an effect on the separation of gases, since their mixing at such a height is negligible. Hence follows the variable composition of the heterosphere. Below it lies a well-mixed, homogeneous part of the atmosphere, called the homosphere. The boundary between these layers is called the turbopause and lies at an altitude of about 120 km.
The upper part of the atmosphere, above the mesosphere, is characterized by very high temperatures and is therefore called the thermosphere. However, two parts are distinguished in it: the ionosphere, which extends from the mesosphere to heights of the order of a thousand kilometers, and the outer part lying above it - the exosphere, passing into the earth's corona.
The air in the ionosphere is extremely rarefied. We have already indicated that at altitudes of 300-750 km its average density is about 10-8-10-10 g/m3. But even with such a low 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 - more than 10 million (107). This is several orders of magnitude greater than the content of gases in 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 greater than in the underlying layers, despite the strong overall rarefaction of the air. These ions are mainly charged oxygen atoms, charged nitric oxide molecules, and free electrons. Their content at altitudes of 100-400 km is about 1015-106 per cubic centimeter.
In the ionosphere, there are several layers, or regions, with maximum ionization, especially at altitudes of 100-120 km (layer E) and 200-400 km (layer F). But even 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 change all the time. Sporadic accumulations of electrons with a particularly high concentration are called electron clouds.
The electrical conductivity of the atmosphere depends on the degree of ionization. Therefore, in the ionosphere, the electrical conductivity of air is generally 1012 times greater than that of the earth's surface. Radio waves experience absorption, refraction and reflection in the ionosphere. Waves longer than 20 m cannot pass through the ionosphere at all: they are already reflected by electron layers of low concentration in the lower part of the ionosphere (at altitudes of 70-80 km). Medium and short waves are reflected by the overlying ionospheric layers.
It is due to reflection from the ionosphere that long-range communication at short waves is possible. Multiple reflections from the ionosphere and the earth's surface allows short waves to zigzag to propagate over long distances, bending around the surface globe. Since the position and concentration of the ionospheric layers are continuously changing, the conditions for absorption, reflection and propagation of radio waves also change. Therefore, reliable radio communication requires continuous study of the state of the ionosphere. Observations on the propagation of radio waves are precisely the means for such research.
In the ionosphere, auroras and a glow of the night sky close to them in nature are observed - a constant luminescence of atmospheric air, as well as sharp fluctuations magnetic field- ionospheric magnetic storms.
Ionization in the ionosphere owes its existence to the action of ultraviolet radiation from the Sun. Its absorption by atmospheric gas molecules leads to the appearance of charged atoms and free electrons, as discussed above. Fluctuations in the magnetic field in the ionosphere and auroras depend on fluctuations in solar activity. Changes in solar activity are associated with changes in the flux of corpuscular radiation coming from the Sun to earth's atmosphere. Namely, corpuscular radiation is of fundamental importance for these ionospheric phenomena.
The temperature in the ionosphere increases with height to very high values. At altitudes of about 800 km it reaches 1000°.
Speaking about the high temperatures of the ionosphere, they mean that particles of atmospheric gases move there at very high speeds. However, the air density in the ionosphere is so low that a body located in the ionosphere, such as a flying satellite, will not be heated by heat exchange with air. The temperature regime of the satellite will depend on the direct absorption of solar radiation by it and on the return of its own radiation to the surrounding space. The thermosphere is located above the mesosphere at an altitude of 90 to 500 km above the Earth's surface. Gas molecules here are highly dispersed, absorb x-rays(X rays) and the short-wave part of the ultraviolet radiation. Because of this, the temperature can reach 1000 degrees Celsius.
the thermosphere basically corresponds to the ionosphere, where ionized gas reflects radio waves back to the Earth - this phenomenon makes it possible to establish radio communications.
