Q12. 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 of 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 visible spectrum of electromagnetic waves of solar radiation.
Question from UPSC Prelims 2023 GS Paper
Explanation : Explanation :
Correct Answer – c
Characteristics of Infrared Waves
Infrared waves are a type of electromagnetic radiation with wavelengths longer than visible light. Unlike the visible spectrum, infrared waves are not visible to the human eye. They represent a significant portion of solar radiation and play a crucial role in various natural processes.
Infrared Radiation and Atmospheric Absorption
One of the key characteristics of infrared waves is their interaction with water vapor in the Earth’s lower atmosphere. These waves are largely absorbed by water vapor, leading to the warming of the Earth’s surface and lower atmosphere. This absorption is a vital component in understanding the Earth’s climate and weather patterns.
Misconceptions About Infrared Radiation and Insolation
Contrary to some beliefs, the total amount of insolation received at the equator is not 10 times that at the poles. However, it is significantly higher due to the angle of sunlight incidence. Additionally, while infrared rays do not constitute two-thirds of insolation, they are a substantial part of the total solar radiation that the Earth receives, influencing the global climate.
