There are different ways of heating and cooling of the atmosphere.
TERRESTRIAL RADIATION
The insolation received by the earth is in short waves forms and heats up its surface.
The earth after being heated itself becomes a radiating body and it radiates energy to the atmosphere in long wave form.
This energy heats up 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. Heat Budget of the Planet Earth
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 the form of currents and further transmits the heat of the atmsphere. 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.
In middle latitudes, most of dirunal (day and night) variation in daily weather are caused by advection alone.
In tropical regions particularly in northern India during summer season local winds called ‘loo’ is the outcome of advection process.
External link: https://ncert.nic.in/ncerts/l/kegy209.pdf
PRACTICE QUESTIONS
QUES . Consider the following statements: UPSC 2024
Statement-I:
The atmosphere is heated more by incoming solar radiation then by terrestrial radiation.
Statement-II:
Carbon dioxide and other greenhouse gases in the atmosphere are good absorbers of long wave radiation.
Which one of the following is correct in respect of the above statements?
(a) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I.
(b) Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I.
(c) Statement-I is correct, but Statement-II is incorrect.
(d) Statement-I is incorrect, but Statement-II is correct.
Ans (d) EXPLANATION: The insolation received by the earth is in short waves forms and heats up its surface. The earth after being heated itself becomes a radiating body and it radiates energy to the atmosphere in long wave form. This energy heats up 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.
