Topic: Earth's Atmosphere.

Objectives: To provide an understanding of the atmosphere and composition of air.

To promote the development of comparison and generalization skills.

Instill a sense of respect for nature.

1. Activation of mental activity.

He is transparent and invisible

Light and colorless gas.

With a weightless scarf

It envelops us.

He is in the forest - thick, fragrant,

Like a healing infusion,

Smells of resinous freshness,

Smells of oak and pine.

In summer it is warm,

It blows cold in winter,

When frost paints the glass

And lies on them like a border.

We don't notice him

We don't talk about him.

We just breathe it in -

After all, we need him.

What was the poem about?

What role does air play on the planet? (Slide 1)

• Protects against meteorites.
• Protects against overheating and frost.
• Protects from harmful sun rays.
• Monitors the climate.

1. Subject message.

Decipher the rebus and determine the topic of the lesson: (Slide 2)

Atom sphere (atmosphere)

Work plan: (Slide 3)

• What is atmosphere?
• What layers does it consist of?
• What is the composition of the atmosphere?

Problem: What will happen on Earth if the atmosphere disappears or its composition changes?

1. Atmosphere.

The atmosphere is the air envelope of the planet. The air that surrounds the Earth is up to 800 kilometers high. Atmosphere (ancient Greek “atmos” - air, “sphere” - ball).(Slide 4)

(Additional information prepared by children.)

The layers of the atmosphere reach a thickness of several kilometers, which create the impression of a light blue dome.

The great 15th-century Italian Leonardo da Vinci wrote in his book “On Painting”: “The blueness of the sky is due to the thickness of illuminated air particles, which is located between the Earth and the blackness above.”

Despite the fact that the air has no color, even the not very clean air of the surface layer of the atmosphere in cities turns out to be unusually transparent in comparison with the most transparent liquid. If we look through a layer of air several meters thick, we do not see it. But if the thickness is several kilometers, we begin to see an air haze. The whole atmosphere is light blue. This is due to its thickness.

The color and brightness of the sky changes as it rises above the earth's surface. The higher we rise, the thinner the layer of air above the observation point, the blue sky and its brightness is lower.

What height is the atmosphere? Let's look at its layers:(Slide 5)

1. Troposphere (from Greek - movement) - starts directly from the earth's surface, rising up to 10 kilometers upward. Clouds form here, thunderstorms and snow are born. The temperature drops to – 70° C. Airplanes fly in the upper layers
2. Stratosphere – stretches from 10 to 50 km in height. It contains a thin ozone layer that protects the planet from the sun's harmful rays. Temperature – 70° C.
3. The mesosphere stretches up to 80 km, in it those caught in the Earth’s gravitational field burn up celestial bodies, meteorites. Temperature – 70° C – 90 ° C.
4. Thermosphere (ionosphere) - conducts electricity, is formed here northern lights. Stretches up to 500 km up. They fly in these layers artificial satellites, space probes.
5. The exosphere is highly discharged, there is almost no air in it.

List the layers of the atmosphere. (Slide 6)

What happens if one of the layers of the atmosphere disappears?

1. Air composition.

What does air consist of?(Slide 7)

Air is a mixture of gases: nitrogen, oxygen, carbon dioxide and others.
The air contains:

21% oxygen,
78% nitrogen,
0.9% noble gases,
0.03% carbon dioxide

And a small amount of hydrogen and water vapor.

What substance is in the air the most?

(Slide 8)

What gas do we smell after a thunderstorm? (Ozone is the smell of freshness.)

Does the composition of the air change? Because of what?

What is the difference in the air composition in a classroom, in a city where there are a lot of cars, and in a forest? (Slide 9)

Fizminutka "Atoms - molecules."

The presenter gives the instruction: “Imagine that we are all atoms. The atoms look like this: the elbows are bent, the hands are pressed to the shoulders. Atoms are constantly moving, from time to time they combine into molecules. The number of atoms in a molecule can be different, it will be determined by the number I name. For example, three: atoms must combine three into each molecule. The molecule will then look like this: three people will stand facing each other in a circle, with their hands joined at the top.”

You can finish by naming the total number of participants - this will be the total circle.

1. The role of the atmosphere.

Are air and atmosphere the same thing or different concepts? (Slide 10)

Tell us again what the role of the atmosphere is for our planet. (Slide 11)

• Protects against harmful radiation
• Protects from harmful sun rays
• Protects against meteorites
• Shapes the climate
• Protects against overheating and frost
• Tolerates sounds and smells
• Provides oxygen to living things

What will happen on Earth if the atmosphere disappears or its composition changes?

(Slide12)

The atmosphere has great value for all life on the planet, therefore it must be protected.

Tell us about airspace security measures.

Exhibition of posters “Protect the atmosphere” and their protection.(Slide 13)

1. Generalization.

Now I will check how carefully you listened to me. If you agree with my statement, then put 0, if not, put 1. You should get the number that I had in mind. (Slide 14)

• Do we live at the bottom of the Water Ocean? (no – 1)
• Is precipitation generated in the atmosphere and wind formed? (Yes – 0)
• Do all planets have an atmosphere? (No – 1)
• Is air a liquid? (No – 1)
• Is air a mixture of gases? (Yes – 0)
• Does the atmosphere protect against meteorites? (Yes – 0)
• Carbon dioxide is the most important gas, it is necessary for human life, do we breathe it? (No – 1)

The resulting number should be: 1,011,001.

1. D\Z.

P. 111, retelling.

Watch the weather and wind.

Experience: (Slide 15)

The atmosphere is the gaseous envelope of the planet. The gases that make up the Earth's atmosphere are called air. Air surrounds us everywhere. Air is invisible to humans and often we don’t even feel it. But if, for example, we wave our hand, we will feel that something is in contact with the hand. Another example: stick your hand out of the window of a speeding car, and it will immediately seem that the air has become dense and elastic. Those who have had the misfortune of being caught in a hurricane will confirm that the air can knock you down, rip roofs off houses, turn cars upside down and even uproot thick trees.

Air consists of tiny particles called molecules. They cannot be seen even with the most powerful microscope. And the distances between molecules in the air are much greater than the sizes of the molecules themselves. Therefore, it is not surprising that we cannot see the air.
Air molecules are in continuous random motion. But why don't they fly away from Earth? After all, there are no obstacles from space that could stop them. The fact is that the Earth attracts air molecules to itself in the same way as all other bodies. Therefore, most of the molecules in the atmosphere are located at the surface of the Earth.

An aneroid barometer is a compact device for measuring atmospheric pressure. For a long time, he also served as the main weather forecaster, indicating “great dryness” or “rains and thunderstorms.”

The higher above the Earth, the fewer molecules remain in the air - it becomes rarefied. In the mountains, at an altitude of 3000 m above sea level, it is already difficult to breathe. Even trained climbers climb the highest peak of the planet Everest (8848 m) with oxygen masks. If a passenger on an airplane flying at an altitude of 10 km breathes air overboard, he will lose consciousness. That's why there are always oxygen masks in the cabin of airplanes. After all, if even a tiny hole appears in the fuselage of an airplane, the air from the cabin will rush out, where the molecules are located much less densely. (For example, train passengers will do exactly the same thing if, during rush hour, an empty car is connected to a crowded carriage). As a result, the air on the plane will become almost unbreathable. The further from the Earth's surface, the fewer molecules remain in the air. It is impossible to say definitely where the atmosphere ends. It is generally accepted that the thickness of the Earth's atmosphere reaches several thousand kilometers.

On the world's highest peak, Everest (8848 m), the air is so thin that almost all climbers who managed to reach this record point used oxygen masks.

All life on our planet is concentrated in the lower, densest layers of the atmosphere - the troposphere. Its thickness varies from 8 km at the poles to 17 km at the equator. Of course, the troposphere is not separated from the upper layers by boundary pillars. But in the troposphere, air temperature decreases with altitude - the higher it is, the colder it is, and in the upper layers of the atmosphere the temperature changes somewhat differently.

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 sizzling 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 scales. And then everyone saw that the ball had become noticeably lighter.

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 heating 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 movement. 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.

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

Formation chemical composition 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 modern form recorded 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 thirtieth latitude - the region 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- lower limit begins at an altitude of 80 - 90 km, and the upper boundary of the layer runs approximately at around 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.