Question

Pick the incorrect statement in the context of the presence of water vapour in the atmosphere.

Options

• Water vapour is a variable gas.

• Its amount increases with altitude.

• Its amount decreases with increasing latitude.

• It acts as a blanket.

Answer 1

Its amount increases with altitude.

Explanation:

Water vapour is a variable gas because its concentration changes with time and place in the atmosphere. Its amount actually decreases with altitude since colder temperatures at higher altitudes reduce evaporation and the water-holding capacity of air. Also, water vapour decreases as we move from the equator towards the poles (increasing latitude) because warmer regions near the equator have more evaporation. Water vapour acts like a blanket by absorbing heat, thus preventing extreme temperature fluctuations on Earth. Therefore, the statement that water vapour increases with altitude is incorrect.