Explain the main layers of the atmosphere ?Troposphere The troposphere is the lowest l f ayer o the atmos h I above the poles and 17 km b h P ere. t extends up to 7 km a ove t e Equator It co · · carbon dioxide which are life s . . · . ntams nitrogen, oxygen and ustainmg gases It 1s the warm l b closest to the Earth's surface and . h h. eSc ayer ecause it is . h' 1 d . receives t e eat reflected by it. The tern erature in t is ayer ecreases with increase . al . d Cl d 1 . . p h h m tltu e. ou s a so form m this layer and w en t ey condense they bring rainfall or snowfall on the Earth. Stratosphere The layer above the troposphere is stratosphere. In this layer) temperature increases with increase in altitude. There are no weather activities in the stratosphere; that is why aeroplanes can fly in this layer without any obstruction.'The stratosphere contains a thin ozone layer which absorbs the harmful ultraviolet rays of the Sun. In recent years, the thickness of this layer has been decreasing. The depletion of ozone layer is caused by environmental pollution. Chemical compounds like CFCs (chlorofluorocarbons) found in aerosol sprays and refrigerators are actually destroying the zone faster. Mesosphere Above the stratosphere lies the mesosphere which extends _from :o to 85 km ~ove 1 Th t mperature decreases with increase in altitude m the mesosp ere our p anet. e e . d g5°c This leads to the ith the minimum temperature dropping own to -. '; . f 1·ce clouds called noctilucent clouds. 1ormat1on o Thermosphere -h l' directly above the mesosphere l f h Earth's atmosp ere ies . . l The thermosphere ayer o t e Th rature increases with height m t 1e 1 h osphere e tempe 500 ac and directly be ow t e ex . . tures reaching about l, . . h h ax1mum tempera thermosphere wit t e m,. I · inly Exosphere f the Earth's atmosphere. t 1s ma The exosphere is the uppermhosl~ laye~toextends into the limitless space where the f h d en and e ium. composed o Y rog d not operate. ​