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HEATING AND COOLING OF THE ATMOSPHERE□
Terrestrial Radiation◇ Earth's surface after receiving insolation from the sun through
shortwave electromagnetic radiation gets heated and radiates heat to the atmosphere in the form of
longwave or infrared radiation throughout
24 hours.◇ It may be remembered that the atmosphere is more or less transparent for incoming shortwave solar radiation but it absorbs more than
90 per cent of outgoing longwave terrestrial radiation through water vapour, carbon dioxide, ozone etc. Thus, the terrestrial radiation is the most important source of heating of the atmosphere. The process of radiation of heat from the earth's surface is called
ground radiation.
◇ The part of this ground radiation after being absorbed by the atmosphere is radiated back to the earth's surface. This process of radiation of terrestrial heat energy from the atmosphere back to the earth's surface is called
counter-radiation which is effected mainly by water vapour and atmospheric carbon dioxide.
