Question

UPSC Prelims 2023 Question:

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

  1. 1. The total amount of insolation received at the equator is roughly about 10 times of that received at the poles.
  2. 2. Infrared rays constitute roughly two-thirds of insolation.
  3. 3. Infrared waves are largely absorbed by water vapour that is concentrated in the lower atmosphere.
  4. 4. Infrared waves are a part of visible spectrum of electromagnetic waves of solar radiation.

Answer (Detailed Solution Below)

Option 3: Infrared waves are largely absorbed by water vapour that is concentrated in the lower atmosphere.

Detailed Solution

Learn more about the Earth Atmosphere in the given explanation below. 

Explanation:

  • The Earth’s surface receives most of its energy in short wavelengths. The energy received by the earth is known as incoming solar radiation, which in short, is termed insolation.
  • The atmosphere is largely transparent to short wave solar radiation. The incoming solar radiation passes through the atmosphere before striking the earth’s surface. Within the troposphere water vapour, ozone and other gases absorb much of the near infrared radiation.

Significance of Earth Atmosphere

  • Protection from Harmful Radiations: The atmosphere protects life on Earth by shielding it from incoming ultraviolet (UV) radiation, keeping the planet warm through insulation, and preventing extremes between day and night temperatures.
  • Weather and climate: The atmosphere play a crucial role in determining weather and climate patterns, including temperature, precipitation, and wind. These patterns have a significant impact on ecosystems, agriculture, and human activities.
  • Regulates the Earth's Temperature: The atmosphere helps regulate the Earth's temperature by trapping heat from the sun and preventing it from escaping into space. This process, known as the greenhouse effect, helps keep the planet warm enough to support life.
  • A Major Role in the Water Cycle: The atmosphere helps regulate the Earth's water cycle by transporting water vapor from the oceans to the land, where it falls as precipitation.

Therefore, option (3) is the correct answer.

Subject: Geography | Climate Weather and Atmosphere

Latest UPSC Exam 2026 Updates

Last updated on Sep, 2026

→ UPSC 2027 Notification will be released on 13 January 2027 at upsconline.nic.in.

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