Question

Discuss the processes through which the earth-atmosphere system maintains heat balance.

Answer 1

1. Conduction:

• The earth after being heated by insolation transmits the heat to the atmospheric layers near to the earth in the long waveform. The air in contact with the land gets heated slowly and the upper layers in contact with the lower layers also get heated.
• It takes place when two bodies of unequal temperature are in contact with one another, there is a flow of energy from the warmer to a 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.

2. Convection:

• The air in contact with the earth rises vertically on heating in the form of currents and further transmits the heat
  of the atmosphere. This vertical heating of the atmosphere is known as convection.
• The convection transfer of energy is confined only to the troposphere.

3. Advection:

• The transfer of heat through the horizontal movement of air is called advection. The horizontal movement of the air is relatively more important than the vertical movement.
• In tropical regions particularly in northern India during the summer season, local winds called ‘loo’ are the outcome of the advection process.