(Sample Material) IAS Online Coaching : India & World Geography

Sample Material of Our Online Coaching Programme

Our planet is enveloped by a keep blanket of gases extending several kilometers above its surface.
Like the lithosphere and hydrosphere, the atmosphere too is an integral part of a gigantic system i.e. earth.
When compared with the radius of our planet, the atmosphere appears to be only a very thin layer of gases.
However, because of the force of gravity, it is inseparable from the Earth.

Atmosphere contains life-giving gases, like oxygen for man and animal, and carbon dioxide for plants.

It also acts like a greenhouse and thus keeps the Earth warmer than it would otherwise be.
The atmosphere, thus, acts like a blanket.
It regulates the heat balance of the Earth and also protects us from the harmful ultraviolet radiation of the sun.
The atmosphere serves as a storehouse for water vapour, which leads to precipitation and hence facilitates the hydrological cycles.

The atmosphere has a layered structure, because of density stratification as a result of which lighter gases move up and denser ones settle down.
The lowermost part of the atmosphere in which we live, and which is the theatre for which we live, and which is the theatre for almost all the weather phenomena is known as the troposphere.
Troposphere literally means the region of ‘mixing’ and has been derived from the Greek word ‘tropos’, meaning mixing or turbulence.
The height of the troposphere at the poles is about 8 km, while at the equator it is about 16 km. This is because there is greater heating at the equator.
Above troposphere is the stratosphere, which is important primarily because of the presence of zone.
This layer of calm and clear air is preferred for high-speed jet flights because of the absence of air pockets.
Also, the near absence of water vapour in this layer prevents the formation of clouds, thus providing pilots with better visibility.
Above stratosphere is mesosphere, which is more of a transitional layer.