Dream Upsc Team has been receiving a lot of support and encouragement from our loving readers for our easy-to-understand articles on Geography. (See Major Ocean Currents: How to learn faster?) Having covered most of the important concepts in Lithosphere and Hydrosphere, in this article, we are going to discuss the composition and structure of the Earth’s Atmosphere in detail.
What is atmosphere?
- We all know that earth is a unique planet due to the presence of life. The air is one among the necessary conditions for the existence of life on this planet. The air is a mixture of several gases and it encompasses the earth from all sides. The air surrounding the earth is called the atmosphere.
- Atmosphere is the air surrounding the earth.
- The atmosphere is a mixture of different gases. It contains life-giving gases like Oxygen for humans and animals and carbon dioxide for plants.
- It envelops the earth all round and is held in place by the gravity of the earth.
- It helps in stopping the ultraviolet rays harmful to the life and maintains the suitable temperature necessary for life.
- Generally, atmosphere extends up to about 1600 km from the earth’s surface. However, 99 % of the total mass of the atmosphere is confined to the height of 32 km from the earth’s surface.
Composition of the atmosphetrong>
- The atmosphere is made up of different gases, water vapour and dust particles.
- The composition of the atmosphere is not static and it changes according to the time and place.
- The atmosphere is a mixture of different types of gases.
- Nitrogen and oxygen are the two main gases in the atmosphere and 99 percentage of the atmosphere is made up of these two gases.
- Other gases like argon, carbon dioxide, neon, helium, hydrogen, etc. form the remaining part of the atmosphere.
- The portion of the gases changes in the higher layers of the atmosphere in such a way that oxygen will be almost negligible quantity at the heights of 120 km.
- Similarly, carbon dioxide (and water vapour) is found only up to 90 km from the surface of the earth.