Question

Write a short note on water vapours.

Answer 1

Water vapour:

• The amount of water vapour decreases with the altitudes. In warm and wet tropics, it accounts for 4% of the air by volume whereas in dry and cold areas of deserts and polar regions, it may be less then 1% of the air.
• It also decreases from the equator towards the poles.
• It absorbs parts of the insolation received from the sun and preserves the earth’s radiated heat and thus acts as a blanket by allowing the earth neither to become too hot nor too cold.