Weather in this area has a strong impact on human life, so information about the state of the earth’s atmosphere is always useful from an economic point of view and from the point of view of safety for health. Temperature inversion is a type of state of the lower atmosphere. What it is and where it appears is considered in the article.
What is temperature inversion?
By this concept is meant an increase in air temperature with increasing height from the earth's surface. This seemingly harmless definition entails quite serious consequences. The fact is that air can be considered an ideal gas, for which the pressure at a fixed volume is inversely dependent on temperature. Since the temperature increases with increasing temperature inversion, the air pressure decreases and its density decreases.
From the school course of physics it is known that convection processes that cause vertical mixing in the volume of a fluid substance located in a gravitational field occur if the lower layers are less dense than the upper ones (hot air always rises). Thus, temperature inversion prevents convection in the lower atmosphere.
Normal atmospheric conditions
As a result of numerous observations and measurements, it was found that in the temperate climatic zone of our planet, air temperature decreases by 6.5 ° C for every kilometer of altitude, that is, by 1 ° C with an increase in height of 155 meters. This fact is due to the fact that the heating of the atmosphere does not occur as a result of the passage of sunlight through it (for the visible spectrum of electromagnetic radiation, the air is transparent), but as a result of the absorption of reradiated energy in the infrared range from the surface of the earth and water. Therefore, the closer the air layers to the ground, the more they warm up on a sunny day.
In the tropical climate zone, the air cools more slowly with increasing altitude than the indicated figures (approximately 1 ° C per 180 m). This is due to the presence of trade winds in these latitudes, which transfer heat from the equatorial regions to the tropics. In this case, heat flows from the upper layers (1-1.5 km) to the lower ones, which prevents a rapid drop in air temperature with increasing height. In addition, the thickness of the atmosphere in the tropical zone is greater than in the temperate.
Thus, the normal state of the atmospheric layers consists in their cooling with increasing height above sea level. This condition favors the mixing and circulation of air in the vertical direction due to convection processes.
Why can the upper air layers be warmer than the lower ones?
In other words, why is temperature inversion manifested? This happens for the same reason as the existence of normal atmospheric conditions. Earth has a greater value of thermal conductivity than air. This means that at night, when there are no clouds and clouds in the sky, it quickly cools and those atmospheric layers that are in direct contact with the earth's surface also cool. The result is the following picture: a cold surface of the earth, a cold layer of air in the immediate vicinity of it, and a warm atmosphere at a certain height.
What is temperature inversion and where does it occur? This situation often arises in the lowlands, in absolutely any locality and at any latitude in the morning. Lowland is protected from horizontal movements of air masses, that is, from the wind, so the air cooled in it during the night creates a locally stable atmosphere. The phenomenon of temperature inversion can be observed in mountain valleys. In addition to the described process of night cooling, in the mountains its formation is also facilitated by the “sliding” of cold air from the slopes to the plains.
The lifetime of temperature inversion can last from several hours to several days. Normal atmospheric conditions are established as soon as the earth's surface heats up.
What is the danger of the phenomenon under consideration?
The state of the atmosphere in which there is a temperature inversion is stable and windless. This means that if any emissions into the atmosphere or the evaporation of toxic substances occur in a given territory, they do not disappear anywhere, but remain in the air above the area in question. In other words, the phenomenon of temperature inversion in the atmosphere contributes to a multiple increase in the concentration of toxic substances in it, which poses a huge danger to human health.
The described situation often arises over large cities and megacities. For example, cities like Tokyo, New York, Athens, Beijing, Lima, Kuala Lumpur, London, Los Angeles, Bombay, the capital of Chile - Santiago and many other cities around the world often suffer from the effects of temperature inversion. Due to the large concentration of people, industrial emissions in these cities are gigantic, which leads to smog in the air, which impairs visibility and poses a threat not only to health but also to human life.
So, in 1952 in London and in 1962 in the Ruhr Valley (Germany), several thousand people died as a result of the long existence of temperature inversion and significant emissions of sulfur oxides into the atmosphere.
Capital of Peru, Lima
Opening the question of what is temperature inversion in geography, it is interesting to bring the situation in the capital of Peru. It is located on the Pacific Ocean and at the foot of the Andes Mountains. The coast near the city is washed by Humboldt, which leads to severe cooling of the earth's surface. The latter, in turn, contributes to the cooling of the lowest air layers and the formation of fogs (with a decrease in air temperature, the solubility of water vapor in it decreases, the latter manifests itself in dew and fog).
As a result of the described processes, a paradoxical situation arises: the coast of Lima is covered with fog, which prevents the rays of the sun from heating the earth's surface. Therefore, the state of temperature inversion is so stable (mountains interfere with horizontal air circulation) that it almost never rains here. The latter fact explains why the coast of Lima is almost a desert.
How to behave in case of receiving information about the adverse state of the atmosphere?
If a person lives in a large city and he has received information about the existence of a temperature inversion in the atmosphere, it is recommended not to go outside in the morning, if possible, but to wait until the earth warms up. If such a need arises, then you should use individual respiratory protective equipment (gauze bandage, scarf) and do not stay outdoors for a long time.
From Wikipedia, the free encyclopedia
There are two types of inversion:
- surface temperature inversions starting directly from the earth's surface (the thickness of the inversion layer is tens of meters)
- temperature inversions in a free atmosphere (inversion layer thickness reaches hundreds of meters)
Temperature inversion prevents vertical air movements and contributes to the formation of haze, fog, smog, clouds, mirages. Inversion strongly depends on local features of the relief. The temperature increase in the inversion layer ranges from tenths of degrees to 15-20 ° C or more. The surface temperature inversions in Eastern Siberia and Antarctica in winter have the greatest power.
Normal atmospheric conditions
As a rule, in the lower atmosphere (troposphere) the air near the Earth’s surface is warmer than the air located above, since the atmosphere is mainly heated by solar radiation through the Earth’s surface. As the altitude changes, the air temperature decreases, the average decrease rate is 1 ° C for every 160 m.
Causes and mechanisms of inversion
Under certain conditions, the normal vertical temperature gradient changes in such a way that the colder air is at the surface of the Earth. This can happen, for example, when a warm, less dense air mass moves over a cold, denser layer. This type of inversion occurs in the vicinity of warm fronts, as well as in areas of ocean upwelling, for example, off the coast of California. With sufficient humidity of the colder layer, fog formation under the inversion “cover” is typical.
The effects of temperature inversion
When the normal convection process ceases, the lower atmosphere is polluted. This causes problems in cities with large emissions. Inversion effects often occur in such large cities as Mumbai (India), Los Angeles (USA), Mexico City (Mexico), São Paulo (Brazil), Santiago (Chile) and Tehran (Iran). Small cities, such as Oslo (Norway) and Salt Lake City (USA), located in the valleys of hills and mountains, are also affected by the blocking inversion layer. With a strong inversion, air pollution can cause respiratory illness. The great smog in 1952 in London is one of the most serious such events - more than 10 thousand people died because of it.
Temperature inversion is a danger to take-off aircraft, since when the aircraft enters the overlying layers of warmer air, the engine thrust decreases.
In winter, inversion can lead to dangerous natural phenomena, such as severe frosts in the anticyclone, freezing rain at the exit of the Atlantic and southern cyclones (especially when passing through their warm fronts).
see also
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Notes
References
- Temperature inversion // Big Soviet Encyclopedia: [in 30 vol.] / Ch. ed. A. M. Prokhorov. - 3rd ed. - M. : Soviet Encyclopedia, 1969-1978.
- Khrgian A. Kh. Atmospheric physics M., 1969
Excerpt (meteorology)
“And in order not to ruin the land that we left to the enemy,” Prince Andrei viciously mockingly said. - This is very thorough; you must not be allowed to rob the land and accustom troops to looting. Well, in Smolensk, he also correctly reasoned that the French could get around us and that they had more strength. But he couldn’t understand that, - suddenly Prince Andrei shouted in a tearing voice, but he couldn’t understand that for the first time we fought for Russian land, that there was such a spirit in the troops as I had never seen, that we fought off the French for two days in a row and that this success tripled our strength. He ordered a retreat, and all efforts and losses were in vain. He did not think about treason, he tried to do everything as best as possible, he considered everything; but that’s why it’s not good. He is no longer fit precisely because he thinks everything thoroughly and carefully, as every German should. How can I tell you ... Well, your father has a German footman, and he is a wonderful footman and will satisfy all his needs better than you, and let him serve; but if your father is sick at death, you will drive away the footman and with your unusual, awkward hands you will go after your father and better calm him down than a skilled, but alien man. So they did with Barclay. While Russia was healthy, a stranger could serve her, and there was a wonderful minister, but as soon as she was in danger; I need my own, dear person. And in your club they thought up that he was a traitor! The fact that he was slandered by a traitor will be done only by the fact that then, ashamed of their false criticism, they will suddenly make of the traitors a hero or a genius, which will still be unfair. He is an honest and very neat German ...“However, they say he is a skilled general,” said Pierre.
“I don’t understand what a skilled commander means,” said Prince Andrew with a mockery.
“A skilled commander,” said Pierre, “well, one who foresaw all contingencies ... well, he guessed the enemy’s thoughts.”
“Yes, this is impossible,” said Prince Andrei, as if about a long-settled matter.
Pierre looked at him in surprise.
“However,” he said, “it is said that war is like a chess game.”
“Yes,” said Prince Andrei, “only with the little difference that in chess over each move you can think as much as you like there outside the conditions of time, and with the difference that a knight is always stronger than a pawn and two pawns are always stronger one, and in war one battalion is sometimes stronger than a division, and sometimes weaker than a company. The relative strength of the troops cannot be known to anyone. Believe me, ”he said,“ that if it depended on the orders of the headquarters, I would be there and make orders, but instead I have the honor to serve here with these gentlemen here in the regiment, and I think that it’s really from us tomorrow will depend, and not on them ... Success has never depended and will not depend either on position, or on weapons, or even on number; and least of all from the position.
- And from what?
“From that feeling that is in me, in him,” he pointed to Timokhin, “in every soldier.”
Prince Andrei looked at Timokhin, who was frightened and perplexed at his commander. In contrast to his former restrained silence, Prince Andrei now seemed agitated. Apparently, he could not resist expressing those thoughts that unexpectedly came to him.
- The battle will win the one who firmly decided to win it. Why did we lose battle at Austerlitz? Our loss was almost equal with the French, but we told ourselves very early that we lost the battle - and lost. And we said this because we had no reason to fight there: as soon as we wanted to leave the battlefield. “Lost - well, so run!” - we ran. If we hadn’t said this before evening, God knows what would have happened. And tomorrow we will not say that. You say: our position, the left flank is weak, the right flank is stretched, ”he continued,“ all this is nonsense, there is none of this. What do we have tomorrow? One hundred million of the most varied accidents that will be solved instantly by the fact that they ran or run, or ours, that they kill one, kill another; and what’s being done now is all fun. The fact is that those with whom you traveled by position, not only do not contribute to the general course of affairs, but interfere with it. They are only occupied with their small interests.
- At such a minute? Pierre said reproachfully.
“At such a minute,” Prince Andrei repeated, “for them it’s only such a minute in which you can dig under the enemy and get an extra cross or ribbon.” For me, for tomorrow, this is what: the hundred thousandth Russian and hundred thousandth French troops came together to fight, and the fact is that these two hundred thousand are fighting, and whoever will fight wicked and spare himself less will win. And if you want, I’ll tell you that, whatever it is, whatever is confused up there, we will win the battle tomorrow. Tomorrow, whatever it is, we will win the battle!
TEMPERATURE INVERSION
TEMPERATURE INVERSION, an abnormal increase in TEMPERATURE with height. Normally, air temperature decreases with increasing altitude. The average rate of decline is 1 ° C for every 160 m. Under certain weather conditions, the opposite situation is observed. On a clear, quiet night with an anticyclone, cold air can slide down the slopes and collect in the valleys, and the air temperature will be lower near the bottom of the valley than 100 or 200 m higher. Over the cold layer there will be warmer air, which is likely to form a cloud or light fog. The temperature inversion becomes apparent by the example of smoke rising from a fire. Smoke will rise vertically, and then, when it reaches the “inversion layer”, it will bend horizontally. If this situation is created on a large scale, dust and dirt rising into the atmosphere remain there and, accumulating, lead to serious pollution.
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See what "TEMPERATURE INVERSION" is in other dictionaries:
Big Encyclopedic Dictionary
temperature inversion - An increase in temperature with height in a certain layer of the atmosphere instead of its usual decrease. Syn .: temperature inversion ... Geography Dictionary
See Temperature Inversion. * * * TEMPERATURE INVERSION TEMPERATURE INVERSION, see Temperature Inversion (see TEMPERATURE INVERSION) ... encyclopedic Dictionary
temperature inversion - temperatūros apgrąža statusas T sritis ekologija ir aplinkotyra apibrėžtis Vietinis oro temperatureūros didėjimas, kylant aukštyn, tam tikruose atmosferos sluoksniuose. Troposferoje temperatūros apgrąžos sluoksnio storis gali būti 2-3 km,…… Ekologijos terminų aiškinamasis žodynas
See Invert Temperature ... Natural History. encyclopedic Dictionary
An increase in air temperature with altitude in a certain layer of the troposphere. Inversions are found in the surface air layer, as well as in the free atmosphere, especially in the lower 2 km. Inversion characteristics include: high. lower bound and vertical ... ... Geographic Encyclopedia