Paragraph Questions:

Write a paragraph about the structure of the atmosphere.

The blanket of air that surrounds the earth’s surface is called atmosphere which is being held close to the earth by gravitational force. The atmosphere is a mixture of gases, water vapour and dust particles in different proportions. Nitrogen and Oxygen are permanent gases of the atmosphere. The other solid particles that are present in the atmosphere include dust particles, salt particles, pollen grains, smoke, soot, volcanic ashes etc. The following diagram shows the layers in the atmosphere:

The structure of the atmosphere consists of five layers:

1. Troposphere:

This is the lowest layer of the atmosphere. It extends up to 8 kilometres at the poles and up to 18 kilometres at the Equator. It is called weather making layer because almost all the weather phenomena take place in his layer.

2. Stratosphere:

The layer lies above the troposphere. It extends to a height of about 50 kilometres above the surface of the earth. This layer is also called “ozonosphere” since this layer has a concentration of ozone molecules. Large jet planes normally fly here.

3. Mesosphere:

This layer lies above the stratosphere and extends between 50 kilometres and 80 kilometres. In the mesosphere, temperature increases as the altitude increases. Most of the meteors nearing the earth get burned here.

4. Thermosphere:

This layer exists above the mesosphere and extends up to 600 kilometres. Thermosphere also contains another layer called “Ionosphere” that contains Ions and free electrons. The "Aurora" mostly occurs in this layer.

5. Exosphere:

This is the uppermost layer of the atmosphere. It is a thin layer where molecules are gravitationally bound to that body. It is same as the airless void of outer space.