Structure of the atmosphere

• We have learned the factors which influencing the temperature• From the earth surface upward

there is a change in temperature, based on this change atmosphere has been divided into different layers

•Troposphere

•Stratosphere

•Mesosphere and

•thermosphere

Troposphere

• The atmospheric layer close to the earths surface is called Troposphere

• The word Troposphere is derived from the Greek word tropos which means turn, air is very turbulent in this region

• Based on the laltiude and season , its heights varies

• At the poles it is 8 km and 17 km over equator. It is based on the temperature

• In the tropics convection current of air extends greater height , but in cold region it is very less

• Temperature in Troposphere decreases steadily with increase in height, called normal lapse rate

• Extension of convectional current determine the height of troposphere

• Temperature in Troposphere decreases steadily with increase in height at the rate of 1 degree per 165 mtr

• All the weather like cloud, rain, thunder are taking place in Troposphere water vapour and dust particles are found only here.

• above the Troposphere s the Tropopause, where temperature is steady

•Tropopause is the transitional zone between troposphere and stratosphere

stratosphere• It situates just above troposphere• In the lower part, temperature is constant• this means when height increases temperature will

not increases . It is for about 30 km from the surface

• Then up to 50 km temperature increases with increasing height

• Ultraviolet rays of the sun absorb by oxygen molecules and split into oxygen atoms and forms ozone layers

• Here temperature increases due to release of latent heat

• Jet planes that fly very height create a white line in the sky this because when planes fly in stratosphere. Steam they release condense and form it . since there is a less movement of air here , thus it visible for a long time• The transitional zone above

stratosphere is called stratopause