The atmosphere

The atmosphere
The surface of the earth is surrounded by layers of gases. The gases above the earth’s crust which cover the earth are called atmosphere. The gases and the composition air that we near the surface of the earth are not uniform. Different gases found in the atmosphere and the temperature gradually change at different heights. So, depending upon the temperature and composition ,atmosphere of the earth is divided into the following.
1.troposphere
This is the layer of atmosphere in which we live. It extends up to 16km high fro the sea level.the temperature with in this layer decreases with the increase of height. Different climatic processes as rain, hailstone, snow, dew,frost,lightening,cloud,etc. occour in this layer.the major components found in this layer are nitrogen, oxygen,co2,inert gases,water vapour and dust particles

2. stratosphere
The layer above the troposphere up to 15km is called stratosphere. The temperature in this layer increases with the increase os height. The upper layer contain a layer of ozone. The ozone layer protect us from the harmful rays of the sun. as stratosphere contain ozone it is also called ozonosphere . ozone is found in the upper boundary of stratosphere,

3.mesosphere
The layer of atmosphere from 50km to 80km is called mesosphere. In this layer temperature decreases with the increase of height. air keeps on glowing in this region .it is very cold layer with a temperature -100 degree Celsius. The lower part is little warmer as it receives heat from the stratosphere just below it.
4.thermosphere
The layer of the atmosphere ranges from 80km to 720km is called thermosphere. The temperature of this layer increases with the increase of height. It is the hottest layer where the temperature reaches 200 degreecelsius . the gaseous materials in this region are in an ionic form. The region is that the gaseous absorbs the UV radiation of sun and get ionized. the mesosphere and thermosphere combinely called ionosphere because the gases present here are in ionic form.

5. exosphere
The layer of atmosphere above the thermosphere is called exosphere. The air density in this layer is the lowest. The temperature of this layer is very high.