The term “atmosphere” in easy words refers to the layer of gases that covers the planet.

The air we breathe is part of the atmosphere, which is a layer of gases covering the Earth. The pull of Earth’s gravity keeps it relatively close to the ground. Air pressure can be determined with the help of a barometer. The three primary components of air are argon, oxygen, and nitrogen. Give us a feel for the ambience here in this piece.

Definition of Atmosphere

The atmosphere serves as a blanket for all life on Earth, regulating the planet’s temperature and shielding us from the sun’s UV radiation.

Atmosphere Characteristics:

• This aids in keeping the sun’s heat on the ground rather than letting it radiate back into space.
• helps to shield living things from the sun’s destructive rays.
• Contributes significantly to the global water cycle.
• The Earth’s climate would be more extreme without it.

The atmosphere and interstellar space are not separated in any way. At higher altitudes, the atmosphere thins out until it “blends” with space.

The lithosphere, hydrosphere, atmosphere, and biosphere are the four natural systems that make up the planet Earth that we call home. For our species to be able to survive on this planet, we require both the knowledge and the comprehension of its various processes.

Only the atmosphere will be discussed in this particular chapter. The study of the elements that make up the atmosphere offers the understanding we have of the relevance of the gases that are present in the atmosphere. The atmosphere is divided into the following four regions: Every region possesses unique natural qualities.

However, the activities of humans are causing disruptions in the natural system. The atmosphere around us is gradually transforming as a result of these actions. In the following chapter, we will talk about the effects that these modifications have had. A significant amount of work is being done on a global scale to mitigate the destructive effects of pollution.

COMPOSITION OF ATMOSPHERE

The term “atmosphere” refers to the layer of a variety of gases that surrounds the planet Earth. It extends in a continuous manner from the surface of the Earth outwards and does not have any boundaries. Approximately 99% of the mass of the atmosphere is located within 30 kilometres of the Earth’s surface, and 75% of this mass is located within the lowest 11 kilometres.

Do you aware that sunlight consists of radiations of short wavelengths?

• On average, there is a total reflection of light of 32%, with 6% of it being reflected from the Earth’s surface and 26% being reflected back into space because of clouds, gases, and dust particles in the atmosphere. • Solar energy that is absorbed by the Earth’s surface is converted into heat energy, which has a longer wavelength. Atmospheric gases are responsible for the absorption of 18% of the sun’s rays. The remaining fifty percent travels down to the surface of the Earth and gets absorbed by it. This energy is radiated into the surrounding space as heat energy with a longer wavelength, which is then absorbed by the water vapour and carbon dioxide in the atmosphere.

LAYERS OF ATMOSPHERE

From the surface of the Earth and moving upward, the atmosphere can be broken down into four distinct spheres, or layers. Because the concentration of the component gases falls gradually as the volume increases, the pressure also decreases gradually as the volume increases. The temperature of the atmosphere, on the other hand, does not vary in a way that is gradual. It differs in a myriad of different ways.

The atmosphere can be broken up into four distinct areas, and each one is characterised by a distinct temperature gradient.

In the lowest layer, which extends up to 12 kilometres, the temperature regularly drops from 17 degrees Celsius to -58 degrees Celsius. The troposphere is the name given to this layer of the atmosphere. The stratosphere begins at this level and can reach a height of up to fifty kilometres. The temperature might reach up to 2 degrees Celsius higher in this layer. The mesosphere begins just below the stratosphere and extends as high as 85 kilometres. Again, temperatures can drop to as low as -93 degrees Celsius in this region. After an altitude of 85 kilometres, one enters the thermosphere, which is characterised by steadily rising temperatures.

The following table provides information regarding the characteristics of the atmosphere’s four different regions:

In this lesson, we will go over the factors that contribute to temperature shifts and other phenomena that occur in the troposphere and the stratosphere.

Troposphere

Nitrogen and oxygen are the two gases that make up the vast majority of the troposphere. These two gases account for 99 percent of the total volume of the atmosphere surrounding the Earth. Despite the fact that the concentration of carbon dioxide and water vapours in the atmosphere is practically nonexistent, both play an important part in the process of keeping the temperature of the atmosphere stable. Both of these gases are transparent to visible light, but they are effective at absorbing infrared radiation that is released from the surface of the earth. As a result, these gases absorb a significant portion of the energy that is emitted, which causes the atmosphere to get warmer. Temperature falls at a rate of 6 degrees Celsius per kilometre when height is increased; this is because the concentration of gases steadily reduces as altitude is increased. This is the part of the world where any kind of weather can be expected. Almost all aircraft fly in this region.

Stratosphere

This area begins just above the troposphere and extends up to a distance of fifty kilometres. The temperature climbs slowly up to 2 degrees Celsius in this part of the world. The increase in temperature that may be observed in the stratosphere can be attributed to the presence of ozone, which, as a result of its ability to absorb radiation, can be found in this area. Within this region, the temperature rises with increasing height, such that the lower layer temperature is around -58 degrees Celsius and the upper layer temperature is approximately 2 degrees Celsius. Figure 14.2 illustrates how the stratosphere can be broken down into distinct temperature zones. Due to the fact that ozone in the top layer of the atmosphere is able to absorb high-energy UV light from the sun, it eventually decomposes into monoatomic oxygen (O) and diatomic oxygen (O2 ).

The mid stratosphere has less UV light passing through it. In this exothermic reaction, the elements oxygen and oxygen dioxide mix to generate ozone. The ozone layer is produced as a direct consequence of the creation of ozone in this region.

As a result, an ozone layer can be found in the middle of the stratosphere.

Due to the extremely low levels of ultraviolet radiation that are received by the lower stratosphere, monoatomic oxygen does not exist here, nor does ozone formation occur.

How Is Atmosphere Useful To Us?

In keeping Earth’s temperature stable, the atmosphere performs a crucial service. Due to the lack of a protective atmosphere, the temperature on the Moon can swing from a scorching 121 degrees Celsius (250 degrees Fahrenheit) in direct sunlight to a frigid minus 157 degrees Celsius (-269 degrees Fahrenheit) (negative 250 degrees Fahrenheit). The atmosphere acts as a shelter against harmful cosmic rays and radiation. In addition to its other functions, the atmosphere is crucial because it facilitates the transport of water. When water vapour rises to the atmosphere from the oceans, it cools and condenses to form rain, which nourishes land areas that would otherwise be parched.

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