gs1medium
With reference to the Earth’s atmosphere, which one of the following statements is correct?
- A.The total amount of insolation received at the equator is roughly about 10 times that received at the poles.
- B.Infrared rays constitute roughly two-thirds of insolation.
- C.Infrared waves are largely absorbed by water vapour that is concentrated in the lower atmosphere.
- D.Infrared waves are a part of the visible spectrum of electromagnetic waves of solar radiation.
▶ Answer & Explanation
Correct answer: C. Infrared waves are largely absorbed by water vapour that is concentrated in the lower atmosphere.
Water vapor is a potent absorber of long-wave infrared radiation. Since water vapor concentration is highest in the lower atmosphere (troposphere) due to evaporation and temperature, it effectively traps this outgoing heat, contributing significantly to the greenhouse effect. The other options are incorrect because insolation difference between equator and poles is not that extreme, infrared rays are a minor component of insolation, and infrared is invisible to the human eye, distinct from the visible spectrum.
Source: UPSC gs1 2023