Layers of atmosphere

Our atmosphere is divided into five layers which are: troposphere, stratosphere, mesosphere, thermosphere and exosphere.

Troposphere: It is the most important layer of the atmosphere. The air we breathe exists here. It has the following features:

• Its average height is 13 km.
• Almost all the weather phenomena occur in this layer. The weather phenomena include: Rainfall, Fog, Hailstorm etc.

  Stratosphere: This layer is just above the troposphere and has the following features:

• It extends to a height of 50 km.
• It is almost free from clouds and associated weather phenomena that occur in the troposphere.
• It is most ideal for flying aeroplanes since it is free from weather phenomena.

  Mesosphere: It is the third layer of the atmosphere and it lies above the stratosphere. It extends upto a height of 80 km. The burning of meteorites on entering from space occurs in this layer.

  Thermosphere: It is the fourth layer and the layer above the mesosphere. In this layer, temperature rises very rapidly with increase in height. Ionosphere is a part of this layer. Thermosphere has the following features:

• It extends between 80 to 400 km.
• It helps in radio transmission. This layer is responsible for reflecting back of the radio waves that are transmitted from the earth.

• Exoosphere: It is the uppermost layer of the atmosphere. It has very thin air. Light gases like helium and hydrogen float into the space from here.