Atmosphere: Structure, Air pressure and Wind System

 

Chapter:3 

Atmosphere : Structure, Air Pressure and Wind System.

Key points: 

* Introducing atmosphere

* Structure of the atmosphere 

* Spread or extent of atmosphere 

* Atmospheric pressure and it's measurement

* Pressure belts of the earth

* Definition of wind 

* Factors of origin and movement of wind 

* Naming and measurement of wind 

Q. What is atmosphere?

Ans: The gaseous uninterrupted envelope of air surrounding the earth from its surface up to some height is known as the Atmosphere. It extends vertically up to an altitude of around 10,000 km from the earth's surface.

Q. Write about global pressure belts.

Ans: On the basis of relative difference in atmospheric pressure mainly four pressure belts are identified in the world.

They are:

a) Equatorial Low Pressure Belt.

b) Sub - Tropical High Pressure Belt .

c) Sub - Polar Low Pressure Belt 

d) Polar High Pressure Belt.