Consider the following data regarding the Heat Budget of the Earth: 1. 35 units are reflected back from the top of the clouds. 2. 14 units are absorbed within the atmosphere. 3. 51 units are absorbed by the earth’s surface. Which of the statements given above is/are correct?

The correct option is 2 and 3 only. Explanation The Heat Budget of the Earth refers to the balance between the amount of incoming solar radiation (insolation) received by the Earth and the amount of terrestrial radiation reflected or emitted back into space. This balance maintains the Earth's average temperature. Standard calculations assume 100 units of incoming solar radiation. Statement-wise Analysis - Statement 1 is Incorrect. While roughly 35 units of the total 100 units are reflected back to space before reaching the Earth's surface (collectively known as the Earth's albedo), they are not entirely reflected by clouds. The breakdown is approximately: - 27 units are reflected from the top of the clouds. - 2 units are reflected from snow and ice-covered areas. - 6 units are scattered to space by the atmosphere. Therefore, attributing all 35 units to reflection from clouds is factually wrong. - Statement 2 is Correct. Out of the remaining 65 units that enter the atmosphere, 14 units are absorbed within the atmosphere by water vapor, dust particles, and gases (such as ozone). - Statement 3 is Correct. The remaining 51 units reach and are absorbed by the Earth's surface. This comprises: - 34 units received as direct solar radiation. - 17 units received as diffuse daylight (scattered radiation). Key Takeaway: The Earth's Albedo (35 units) consists of reflection from clouds (27), the surface (2), and scattering (6). The remaining 65 units are absorbed: 14 by the atmosphere and 51 by the Earth's surface.

Consider the following data regarding… - NCERT Class 11 Geography MCQ

NCERT Class 11 Geography — Chapter 2: Solar radiation, heat balance and temperature

mcqhard

Consider the following data regarding the Heat Budget of the Earth:

35 units are reflected back from the top of the clouds.
14 units are absorbed within the atmosphere.
51 units are absorbed by the earth’s surface.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Fundamentals of Physical Geography · Page 3

Options

A1 and 2 only
B2 and 3 only
C2 only
D1, 2 and 3

Did you get this right?

Solution

The correct option is 2 and 3 only.

Explanation

The Heat Budget of the Earth refers to the balance between the amount of incoming solar radiation (insolation) received by the Earth and the amount of terrestrial radiation reflected or emitted back into space. This balance maintains the Earth's average temperature. Standard calculations assume 100 units of incoming solar radiation.

Statement-wise Analysis

Statement 1 is Incorrect.
While roughly 35 units of the total 100 units are reflected back to space before reaching the Earth's surface (collectively known as the Earth's albedo), they are not entirely reflected by clouds. The breakdown is approximately:
- 27 units are reflected from the top of the clouds.
- 2 units are reflected from snow and ice-covered areas.
- 6 units are scattered to space by the atmosphere.
Therefore, attributing all 35 units to reflection from clouds is factually wrong.
Statement 2 is Correct.
Out of the remaining 65 units that enter the atmosphere, 14 units are absorbed within the atmosphere by water vapor, dust particles, and gases (such as ozone).
Statement 3 is Correct.
The remaining 51 units reach and are absorbed by the Earth's surface. This comprises:
- 34 units received as direct solar radiation.
- 17 units received as diffuse daylight (scattered radiation).

Key Takeaway:
The Earth's Albedo (35 units) consists of reflection from clouds (27), the surface (2), and scattering (6). The remaining 65 units are absorbed: 14 by the atmosphere and 51 by the Earth's surface.

Your note

More from Chapter 2: Solar radiation, heat balance and temperature

Consider the following statements regarding the insolation received at the Earth's surface: 1. Generally, at the same latitude, insolation is more over the continent than over the oceans. 2. In winter, the middle and higher latitudes receive more radiation than in summer. 3. The subtropical deserts receive more insolation than the equator. Which of the statements given above is/are correct?

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With reference to the specific heat of land and water, consider the following statements: 1. The variation in temperature over the sea is much greater compared to land. 2. Land heats up and cools down more quickly than the sea. 3. Places near the sea experience extreme temperature variations. Which of the statements given above is/are correct?

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In the context of the heat budget, what percentage of incoming solar radiation is reflected back to space before reaching the earth's surface?

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