Heating & Cooling of the Atmosphere - Notes | Geography for UPSC 2024 (Pre & Mains) PDF Download

 Page 1


 
 
HEATING AND COOLING OF THE ATMOSPHERE 
There are different ways of heating and cooling of the 
atmosphere 
Conduction  
? Conduction takes place when two bodies of unequal 
temperature are in contact with one another, there is 
a flow of energy from the warmer to cooler body.  
? The transfer of heat continues until both the bodies 
attain the same temperature or the contact is broken.  
? Conduction is important in heating the lower layers of 
the atmosphere.  
? The earth after being heated by insolation transmits 
the heat to the atmospheric layers near to the earth in 
long wave form. 
? The air in contact with the land gets heated slowly 
and the upper layers in contact with the lower layers 
also get heated. This process is called conduction.  
Convection  
? The air in contact with the earth Rises vertically on 
heating in form of current and further transmits the 
heat of the atmosphere  
? This process of vertical heating of the atmosphere is 
known as convection . 
? The convective transfer of energy is confined only to 
the troposphere . 
Advection: 
Page 2


 
 
HEATING AND COOLING OF THE ATMOSPHERE 
There are different ways of heating and cooling of the 
atmosphere 
Conduction  
? Conduction takes place when two bodies of unequal 
temperature are in contact with one another, there is 
a flow of energy from the warmer to cooler body.  
? The transfer of heat continues until both the bodies 
attain the same temperature or the contact is broken.  
? Conduction is important in heating the lower layers of 
the atmosphere.  
? The earth after being heated by insolation transmits 
the heat to the atmospheric layers near to the earth in 
long wave form. 
? The air in contact with the land gets heated slowly 
and the upper layers in contact with the lower layers 
also get heated. This process is called conduction.  
Convection  
? The air in contact with the earth Rises vertically on 
heating in form of current and further transmits the 
heat of the atmosphere  
? This process of vertical heating of the atmosphere is 
known as convection . 
? The convective transfer of energy is confined only to 
the troposphere . 
Advection: 
 
 
? The transfer of heat through horizontal movement of 
air is called advection. 
? Horizontal movement of the air is relatively more 
important than the vertical movement 
Radiation  
? The insolation received by the earth heats up its 
surface  
? The earth after being heated becomes a radiating 
body in itself and it radiates back to the atmosphere 
in long wave form  
? This energy heats of the atmosphere from below. This 
process is known as Terrestrial radiation. 
? The long wave radiation is absorbed by the 
atmospheric gases particularly by carbon dioxide and 
the other green house gases.  
? Thus, the atmosphere is indirectly heated by the 
earth’s radiation.  
? The atmosphere in turn radiates and transmits heat 
to the space.  
? Finally the amount of heat received from the sun is 
returned to space, thereby maintaining constant 
temperature at the earth’s surface and in the 
atmosphere 
Why is the outgoing radiation in the long waveform while 
incoming days are shortwave radiation?  
 
Page 3


 
 
HEATING AND COOLING OF THE ATMOSPHERE 
There are different ways of heating and cooling of the 
atmosphere 
Conduction  
? Conduction takes place when two bodies of unequal 
temperature are in contact with one another, there is 
a flow of energy from the warmer to cooler body.  
? The transfer of heat continues until both the bodies 
attain the same temperature or the contact is broken.  
? Conduction is important in heating the lower layers of 
the atmosphere.  
? The earth after being heated by insolation transmits 
the heat to the atmospheric layers near to the earth in 
long wave form. 
? The air in contact with the land gets heated slowly 
and the upper layers in contact with the lower layers 
also get heated. This process is called conduction.  
Convection  
? The air in contact with the earth Rises vertically on 
heating in form of current and further transmits the 
heat of the atmosphere  
? This process of vertical heating of the atmosphere is 
known as convection . 
? The convective transfer of energy is confined only to 
the troposphere . 
Advection: 
 
 
? The transfer of heat through horizontal movement of 
air is called advection. 
? Horizontal movement of the air is relatively more 
important than the vertical movement 
Radiation  
? The insolation received by the earth heats up its 
surface  
? The earth after being heated becomes a radiating 
body in itself and it radiates back to the atmosphere 
in long wave form  
? This energy heats of the atmosphere from below. This 
process is known as Terrestrial radiation. 
? The long wave radiation is absorbed by the 
atmospheric gases particularly by carbon dioxide and 
the other green house gases.  
? Thus, the atmosphere is indirectly heated by the 
earth’s radiation.  
? The atmosphere in turn radiates and transmits heat 
to the space.  
? Finally the amount of heat received from the sun is 
returned to space, thereby maintaining constant 
temperature at the earth’s surface and in the 
atmosphere 
Why is the outgoing radiation in the long waveform while 
incoming days are shortwave radiation?  
 
 
 
? Shortwave radiation (visible light) contains a lot of 
energy; longwave radiation (infrared light) contains 
less energy than shortwave radiation. 
? The sun emits shortwave radiation because it is 
extremely hot and has a lot of energy to give off.  
? Once in the Earth’s atmosphere, clouds and the 
surface absorb the solar energy.  
?  The ground heats up and re-emits energy as 
longwave radiation in the form of infrared rays.  
Earth emits longwave radiation because  
? Earth is cooler than the sun and has less energy 
available to give off. 
 
?