The world around is formed from three very different parts: earth, water and air. Each of them is unique and interesting in its own way. Now we will talk only about the last of them. What is the atmosphere? How did it come about? What is it divided into and what parts? All these questions are extremely interesting.
The name "atmosphere" is formed from two words of Greek origin, translated into Russian, they mean "steam" and "ball." And if you look at the exact definition, you can read the following: "The atmosphere is the air envelope of the planet Earth, which is carried along with it in outer space." It developed in parallel with the geological and geochemical processes that took place on the planet. And today all processes occurring in living organisms depend on it. Without atmosphere, the planet would become a lifeless desert like the moon.
What is it made of?
The question of what the atmosphere is and what elements it contains has interested people for a long time. The main components of this shell were already known in 1774. They were set by Antoine Lavoisier. He found that the composition of the atmosphere is mostly formed from nitrogen and oxygen. Over time, its components were refined. And now it is known that there are still many other gases in it, as well as water and dust.
Let us consider in more detail what constitutes the atmosphere of the Earth near its surface. The most common gas is nitrogen. It contains a little more than 78 percent. But, despite such a large amount, nitrogen is practically inactive in the air.
The next in quantity and very important element is oxygen. This gas contains almost 21%, and it shows very high activity. Its specific function is to oxidize dead organic matter, which is decomposed as a result of this reaction.
Gases with low but important value
The third gas that is part of the atmosphere is argon. Its slightly less than one percent. After it goes carbon dioxide with neon, helium with methane, krypton with hydrogen, xenon, ozone and even ammonia. But they are contained so little that the percentage of such components is equal to the hundredth, thousandth and millionths. Of these, only carbon dioxide plays a significant role, since it is the building material that plants need for photosynthesis. Its other important function is not to transmit radiation and absorb part of the solar heat.
Another small but important gas - ozone exists to keep the ultraviolet radiation coming from the sun. Thanks to this property, all life on the planet is reliably protected. On the other hand, ozone affects the temperature of the stratosphere. Due to the fact that it absorbs this radiation, the air is heated.
The constancy of the quantitative composition of the atmosphere is maintained by non-stop mixing. Its layers move both horizontally and vertically. Therefore, there is enough oxygen anywhere in the world and there is no excess carbon dioxide.
What else is in the air?
It should be noted that steam and dust can be detected in the airspace. The latter consists of pollen and soil particles, in the city they are joined by impurities of solid emissions from exhaust gases.
But there is a lot of water in the atmosphere. Under certain conditions, it condenses, and clouds and fog appear. In fact, this is the same thing, only the first ones appear high above the surface of the Earth, and the last one spreads along it. Clouds take a variety of forms. This process depends on the height above the Earth.
If they were formed in 2 km above the land, then they are called layered. It is from them that rain falls on the ground or snow falls. Cumulus clouds form up to a height of 8 km. They are always the most beautiful and picturesque. They are considered and wondered what they look like. If such formations appear on the next 10 km, they will be very light and airy. Their name is cirrus.
What layers is the atmosphere divided into?
Although they are very different from each other temperature, it is very difficult to say at what particular height of one layer starts and another ends. This division is rather conditional and is approximate. However, the atmosphere still exist and perform their functions.
The lowest part of the air envelope is called the troposphere. Its thickness increases when moving from the poles to the equator from 8 to 18 km. This is the warmest part of the atmosphere, since the air in it is heated from the earth's surface. Most of the water vapor is concentrated in the troposphere, so clouds are formed in it, precipitation falls, thunderstorms rattle and wind blows.
The next layer is about 40 km thick and is called the stratosphere. If the observer moves to this part of the air, he will find that the sky has turned purple. This is due to the low density of the substance, which practically does not disperse the sun's rays. It is in this layer that jet planes fly. All open spaces are open for them, since there are practically no clouds. Inside the stratosphere there is a layer consisting of a large amount of ozone.
After it go stratopause and mesosphere. The latter is about 30 km thick. It is characterized by a sharp decrease in the density of air and its temperature. The sky for the observer is seen in black. Here you can even watch the stars during the day.
Layers with almost no air
The atmosphere under the name of the thermosphere continues the structure of the atmosphere - the longest of all the others, its thickness reaches 400 km. This layer has a huge temperature, which can reach 1700 ° C.
The last two spheres are often combined into one and call it the ionosphere. This is due to the fact that in them reactions proceed with the release of ions. It is these layers that make it possible to observe such a phenomenon of nature as the northern lights.
The next 50 km from Earth is assigned to the exosphere. This is the outer shell of the atmosphere. It is the dispersion of air particles into space. Weather satellites are usually moved in this layer.
Earth's atmosphere ends with the magnetosphere. It was she who sheltered most of the artificial satellites of the planet.
After all this, there should be no questions about what the atmosphere is. If you have doubts about its necessity, then they are easy to dispel.
The main function of the atmosphere is to protect the surface of the planet from overheating in the daytime and excessive cooling at night. The next importance of this shell, which no one will dispute, is to supply all living creatures with oxygen. Without this, they would suffocate.
Most meteorites burn in the upper layers, and not reaching the surface of the Earth. And people can admire the flying lights, taking them for the shooting stars. Without an atmosphere, the whole earth would be littered with craters. And about protection from solar radiation already mentioned above.
How does a person influence the atmosphere?
Very negative. This is due to the growing activity of people. The main share of all negative aspects is accounted for by industry and transport. By the way, cars emit almost 60% of all pollutants that penetrate into the atmosphere. The remaining forty are divided between energy and industry, as well as industries for the destruction of waste.
The list of harmful substances that daily replenish the composition of the air is very long. Because of the transport in the atmosphere are: nitrogen and sulfur, carbon, blue and soot, as well as a strong carcinogen causing skin cancer - benzopyrene.
The industry includes the following chemical elements: sulfur dioxide, hydrocarbon and hydrogen sulfide, ammonia and phenol, chlorine and fluorine. If the process continues, then soon the answers to the questions: “What is the atmosphere? What is it made of? ”Will be completely different.