With reference to the Earth’s atmosphere, which one of the following s

With reference to the Earth’s atmosphere, which one of the following statements is correct?

The total amount of insolation received at the equator is roughly about 10 times of that received at the poles.
Infrared rays constitute roughly two-thirds of insolation.
Infrared waves are largely absorbed by water vapour that is concentrated in the lower atmosphere.
Infrared waves are a part of visible spectrum of electromagnetic waves of solar radiation.
This question was previously asked in
UPSC IAS – 2023
The correct answer is C) Infrared waves are largely absorbed by water vapour that is concentrated in the lower atmosphere.
Statement C is correct. Water vapour is a potent greenhouse gas and strongly absorbs infrared radiation, particularly the outgoing longwave radiation emitted by the Earth’s surface. Water vapour is indeed concentrated in the lower atmosphere (troposphere). This absorption is a key mechanism of the greenhouse effect.
Statement A is incorrect; the total amount of insolation at the equator is roughly double (not 10 times) the average received at the poles over a year, due to the lower angle of incidence at the poles and longer atmospheric path. Statement B is incorrect; while infrared is part of insolation, it constitutes roughly half (around 49-50%) of the total solar radiation received at the top of the atmosphere, not two-thirds. Visible light constitutes about 43%. Statement D is incorrect; infrared waves have longer wavelengths than visible light and are not part of the visible spectrum. The visible spectrum ranges from approximately 400 nm (violet) to 700 nm (red), while infrared radiation has wavelengths from about 700 nm up to 1 mm.
Exit mobile version