Call
WhatsApp
Atmosphere is a thin layer that shields us from the dangerous radiations from space. The atmosphere is a mixture of gases which surrounds the earth. Atmosphere is responsible for the climate that we experience in the earth. Atmosphere maintains the warm condition in earth. It also balance the temperature difference in day and night. It also shields us from the harmful ultraviolet (UV) radiation coming from the Sun.
The atmosphere of earth is the combination of 5 layers or we can say that the atmosphere is divided into 5 layers. Lets see the Importance of each layer. The 5 layers of earth atmosphere are
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
- Exosphere
These layers are depicted In the figure below.
- Troposphere
Troposphere is the lowest layer of the earth’s atmosphere.
It extends up to 8 to 12 Km above the surface.
Troposphere is thin in North and south pole, which means the thickness of troposphere is not same in every part of the Earth.
The name “Tropos” means change.
We can find most of the clouds, water vapor and dust can be found in this layer.
All weather changes happen here in Troposphere.
Troposphere consists of air that we breathe. It consists of 78% nitrogen, 21% oxygen and 1% of argon, water vapor, and carbon dioxide.
As we move up in the layer the amount of oxygen decreases, that is why the mountaineers feel problems in breathing.
Temperature decreases (becomes colder) as we move up in the layer. That’s why top portion of mountains covers with snow.
You can find the commercial planes in troposphere.
We can find the presence of storm and turbulence in this layer.
The boundary between the troposphere and the stratosphere is called the “tropopause”.
- Stratosphere
The stratosphere layer lies just above the troposphere.
The thickness of this layer is 35 KM.
Stratosphere is the layer that consists of ozone layer. This layer consists of Ozone a molecule composed of three atoms of oxygen.
The main work of ozone layer is to block harmful UV rays from the Sun.
The temperature in the stratosphere increases as we move up. It is because of the absorption of ultraviolet (UV) radiation from the sun by this ozone.
So, the air is colder in the bottom of stratosphere and warmer in the top.
The presence of water vapor is less in stratosphere. Because of this we can find some clouds here.
We can find jet aircraft and weather balloons in stratosphere.
The boundary between stratosphere and mesosphere is called the stratopause.
- Mesosphere
The mesosphere is located above the stratosphere and below the thermosphere.
The thickness of mesosphere is 35 KM.
As we move up through mesosphere the temperature decreases.
The temperature is about -90 degree Celsius near the top portion of mesosphere, which is the coldest temperature in the earth’s atmosphere.
Most meteors burn in the mesosphere creating “shooting stars”.
When the meteor enters the Mesosphere, air present in this layer creates a friction, which in turn heat up the meteor. Therefore, most meteors burns in the mesosphere.
The boundary between the mesosphere and the thermosphere is called the mesopause.
- Thermosphere
The thermosphere is directly above the mesosphere and below the exosphere.
It extends up to 600 Km.
The temperature in this layer can reach up to 4,500 degrees Fahrenheit so it is the hottest layer of our Earth’s atmosphere.
The thermosphere absorbs Ultraviolet radiation, visible light, and high-energy gamma radiation which makes this layer too hot.
Since the air density is less, we can’t experience the high temperature at this layer.
Most of the part of thermosphere is considered as the outer space region.
Karman line is the internationally recognized boundary of space which lies in this layer. This imaginary line lies 100 KM above the sea level.
We can find International Space Station and low earth satellites in this layer.
- Exosphere
The exosphere is the outermost layer of Earth’s atmosphere.
The thickness of exosphere is about 10,000 Km.
There is no upper boundary for exosphere as it gradually fades with the outer space.
The influence of Earth’s gravity is so small here that molecules of gas escape into outer space.
We can find many satellites in this region. This region of Earth’s atmosphere consists of only a small amount of air, such that satellite can orbit around the earth without much friction.