The atmosphere of the earth in a drawing for children. Atmosphere lesson plan on the surrounding world (2nd grade) on the topic. Atmospheric layers of the Earth - explanation for children

What is atmosphere?

Our entire planet is shrouded in a dense layer of air. This layer is called the Earth's atmosphere. The closer the air is to the surface, the denser it is. Rising higher, you can feel how the density of the air decreases, it becomes rarefied. And where the atmosphere ends and space begins, there is airless space.

Without an atmosphere there would be no life on Earth, because living beings would have nothing to breathe. The air envelope influences the climate on the planet, protects the Earth from the scorching heat of the sun and cosmic cold.

If the Earth were not covered with a shell of air, humanity would suffer from celestial projectiles - meteorites. Before falling to the ground, meteorites collide with layers of the atmosphere, their flight slows down, they heat up and burn without causing harm to earthlings.

The weight of air was first measured by Galileo Galilei. And this happened 300 years ago. The great scientist took a metal ball, made a hole in it, weighed it, and wrote down the weight. Then he pumped out the air from the ball, sealed the hole tightly and put it back on the scale. And then everyone saw that the ball had become noticeably lighter.

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.

The world around us 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 atmosphere? How did it come about? What does it consist of and into what parts is it divided? All these questions are extremely interesting.

The name “atmosphere” itself 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 shell of the planet Earth, which rushes 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 an atmosphere, the planet would become a lifeless desert, like the Moon.

What does it consist of?

The question of what the atmosphere is and what elements are included in it has interested people for a long time. The main components of this shell were already known in 1774. They were installed by Antoine Lavoisier. He discovered that the composition of the atmosphere was largely composed of nitrogen and oxygen. Over time, its components were refined. And now it is known that it contains many other gases, as well as water and dust.

Let's take a closer look at what makes up the Earth's atmosphere near its surface. The most common gas is nitrogen. It contains slightly more than 78 percent. But, despite such a large amount, nitrogen is practically inactive in the air.

The next element in quantity and very important in importance is oxygen. This gas contains almost 21%, and it exhibits very high activity. Its specific function is to oxidize dead organic matter, which decomposes as a result of this reaction.

Low but important gases

The third gas that is part of the atmosphere is argon. It's a little less than one percent. After it come carbon dioxide with neon, helium with methane, krypton with hydrogen, xenon, ozone and even ammonia. But there are so few of them that the percentage of such components is equal to hundredths, thousandths 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 to block radiation and absorb some of the sun's heat.

Another small but important gas, ozone exists to trap 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 heats up.

The constancy of the quantitative composition of the atmosphere is maintained by non-stop mixing. Its layers move both horizontally and vertically. Therefore, anywhere on the globe there is enough oxygen and no excess carbon dioxide.

What else is in the air?

It should be noted that steam and dust can be found 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 essence, these are the same thing, only the former appear high above the surface of the Earth, and the latter spreads along it. Clouds take different shapes. This process depends on the height above the Earth.

If they formed 2 km above land, then they are called layered. It is from them that rain pours on the ground or snow falls. Above them, cumulus clouds form up to a height of 8 km. They are always the most beautiful and picturesque. They are the ones who look at them and wonder what they look like. If such formations appear in the next 10 km, they will be very light and airy. Their name is feathery.

What layers is the atmosphere divided into?

Although they have very different temperatures from each other, it is very difficult to tell at what specific height one layer begins and the other ends. This division is very conditional and is approximate. However, the layers of the atmosphere still exist and perform their functions.

The lowest part of the air shell is called the troposphere. Its thickness increases as it moves from the poles to the equator from 8 to 18 km. This is the warmest part of the atmosphere because the air in it is heated by the earth's surface. Most of the water vapor is concentrated in the troposphere, which is why clouds form, precipitation falls, thunderstorms rumble and winds blow.

The next layer is about 40 km thick and is called the stratosphere. If an observer moves into this part of the air, he will find that the sky has turned purple. This is explained by the low density of the substance, which practically does not scatter 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 large amounts of ozone.

After it come the stratopause and mesosphere. The latter is about 30 km thick. It is characterized by a sharp decrease in air density and temperature. The sky appears black to the observer. Here you can even watch the stars during the day.

Layers in which there is practically no air

The structure of the atmosphere continues with a layer called the thermosphere - the longest of all the others, its thickness reaches 400 km. This layer is distinguished by its enormous temperature, which can reach 1700 °C.

The last two spheres are often combined into one and called the ionosphere. This is due to the fact that reactions occur in them with the release of ions. It is these layers that make it possible to observe such a natural phenomenon as the northern lights.

The next 50 km from the Earth are allocated to the exosphere. This is the outer shell of the atmosphere. It disperses air particles into space. Weather satellites usually move in this layer.

The Earth's atmosphere ends with the magnetosphere. It is she who sheltered most of the planet’s artificial satellites.

After all that has been said, there should be no questions left about what the atmosphere is. If you have any doubts about its necessity, they can be easily dispelled.

The meaning of atmosphere

The main function of the atmosphere is to protect the planet's surface from overheating during the day and excessive cooling at night. The next important purpose of this shell, which no one will dispute, is to supply oxygen to all living beings. Without this they would suffocate.

Most meteorites burn up in the upper layers, never reaching the Earth's surface. And people can admire the flying lights, mistaking them for shooting stars. Without an atmosphere, the entire Earth would be littered with craters. And protection from solar radiation has already been discussed 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 falls on industry and transport. By the way, it is cars that emit almost 60% of all pollutants that penetrate into the atmosphere. The remaining forty are divided between energy and industry, as well as waste disposal industries.

The list of harmful substances that daily replenish the air is very long. Due to transport in the atmosphere there are: nitrogen and sulfur, carbon, blue and soot, as well as a strong carcinogen that causes skin cancer - benzopyrene.

The industry accounts for the following chemical elements: sulfur dioxide, hydrocarbons and hydrogen sulfide, ammonia and phenol, chlorine and fluorine. If the process continues, the questions will soon be answered: “What is the atmosphere? What does it consist of? will be completely different.

When we read about human exploration of the Moon and planets, we often come across questions regarding the atmosphere. Do other planets have atmospheres? As far as scientists know, no planet or star has an atmosphere similar to ours.

What is atmosphere? We can imagine it as an ocean of air surrounding the Earth and several hundred miles high. The ocean of air has the same composition throughout the Earth. It mainly consists of certain gases that always remain in the same proportion. About 78 percent is nitrogen, 21 percent is oxygen, and the remaining one percent is made up of gases called rare - argon, neon, helium, krypton and xenon.

The air that envelops the Earth has the same chemical composition up to an altitude of 18 miles, although this figure can reach up to 44 miles. When you reach the top of the atmosphere, you are at the top of what is called the troposphere. This is the layer closest to the Earth's surface. At an altitude of 18 to 31 miles from the Earth's surface there is a layer of hot air with a temperature of about 42 degrees Celsius. The reason for the heating of this layer is the absorption of heat from the sun's rays by the ozone present here.

Ozone is a special form of oxygen where the molecule consists of three oxygen atoms instead of the usual two. The hot ozone layer serves to protect us from the sun's most active rays - ultraviolet rays. Without it, we would not be able to withstand sunlight. Higher still is a layer or layers called the ionosphere, ranging from 44 to 310 miles above the earth. The ionosphere consists of particles electrified by the Sun. Air molecules are in constant motion. The atmosphere can only be maintained if the molecules constantly collide with each other and cannot escape. But the higher you go, the thinner the air becomes.

There is very little chance that the molecule below will bounce back after colliding with the molecule above. Therefore, the molecules escape into open space, and the atmosphere is completely rarefied. There is a zone called the exosphere where broken-off molecules move almost freely, and this zone starts at an altitude of 400 miles and extends to 1,500 miles.

Let's imagine that we get up at 7:00 in the morning and fall asleep at 23:00. Arriving home from work at about 18:30, we have dinner and leave after 20:00. It's already dark to go outside and relax. There is absolutely no time to enjoy a summer day.

Now imagine that we move the clock forward one hour. A person does everything at the same time - but now, when he goes out in the evening at 20:00, there is still enough daylight to rest. He “won” an hour of daylight!

Of course, daylight saving time does not add hours to the day. This is impossible. This is done in order to increase the number of hours during daylight hours, when the sun rises very early.

Summer time is especially convenient for city dwellers. It allows shops, offices, and factories to close at the end of the working day, when the sun is still high enough. Farmers and peasants who work in the sun usually do not switch to daylight saving time. They cannot work in the field until the morning dew has dried or after it appears in the evening.

Do you know who invented summer time?

Benjamin Franklin! In the 18th century, while in France, he proposed this innovation to the Parisians, but they did not accept it.

The first law on summer time was passed during the First World War. At that time, there was not enough fuel to produce electricity, so it was necessary to conserve it. With the adoption of daylight saving time, many people go to bed immediately after dark, whereas without it, if one had to stay awake until that time, one would have to use electricity.

Germany was the first to adopt daylight saving time in 1915, followed by England in 1916 and the United States in 1918.