Discuss the structure of the Earth …

Structure of atmosphere

1 Troposphere- this is the lowermost layer of the atmosphere . It's average height is 16 km , although it is only 10 km at the poles than at the equator . Temperature decreases with height in This layer , roughly at the rate of 1 degree Celsius for 165 metres ( or consequently 0. 65 degree Celsius per 100 meters ) of ascent . This is known as normal lapse rate . 2. Stratosphere- it extends uoto height of 50 km . It is thicker at the poles than at the equator the Temperature remains almost constant in its lower portion uoto a height of 20 km consequently , it is known as stratosphere. 3 Mesosphere - it lies above stratosphere and extends from 50to 90 km . 4. Heterosphere ( thermosphere ) - heterosphere extends above the homosphere i.e . Above the level of Mesosphere . It has hetrogeneous chemical composition with alter structure of nitrogen, oxygen , helium and hydrogen. 5 . Ionosphere - it extends from 100 to 400 km and lies above Mesosphere . It contains electrically charged particles which are known as ions, hence Thus layer is called ionosphere 6. Exosphere - the upper most layer of the atmosphere beyond the ionosphere above a height of about 400 km is known as exosphere