Consider the following statements about the heating of the lower layers of the atmosphere: 1. Conduction is the least important process in heating the lower layers of the atmosphere. 2. The air in contact with the land gets heated slowly. 3. The upper layers in contact with the lower layers get heated through conduction. Which of the statements given above is/are correct?

The correct option is 2 and 3 only. Explanation The heating of the atmosphere involves four primary processes: radiation (incoming solar and outgoing terrestrial), conduction, convection, and advection. The lower atmosphere is primarily heated by the earth's surface through longwave terrestrial radiation and direct contact mechanisms like conduction and convection. Statement-wise Analysis - Statement 1 is Incorrect: Conduction is the process where heat flows from a warmer object to a cooler object when they are in contact. For the atmosphere, the air touching the warm earth is heated by conduction. Standard physical geography texts explicitly state that conduction is important in heating the lower layers of the atmosphere. Therefore, labeling it as the "least important" process for the lower layers is factually incorrect. - Statement 2 is Correct: Air is a known poor conductor of heat (an insulator). Consequently, the transfer of heat from the land surface to the air in contact with it occurs relatively slowly compared to other modes of heat transfer like convection or radiation. - Statement 3 is Correct: According to the principles of atmospheric heating, the layer of air immediately in contact with the ground gets heated first. This layer then transfers heat to the adjacent upper layers through contact. This specific layer-to-layer transfer mechanism is defined as conduction, even though convection becomes the dominant force for vertical mixing once the air becomes buoyant. Key Takeaway Conduction is the primary mechanism for heating the thin layer of air directly in contact with the earth's surface. Convection is responsible for the vertical transport of this heat into the upper atmosphere, while Advection handles horizontal heat transfer.

Consider the following statements about the heating of the… - NCERT Class 11 Geography MCQ

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

mcqmedium

Consider the following statements about the heating of the lower layers of the atmosphere:

Conduction is the least important process in heating the lower layers of the atmosphere.
The air in contact with the land gets heated slowly.
The upper layers in contact with the lower layers get heated through conduction.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Fundamentals of Physical Geography · Page 2

Options

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

Did you get this right?

Solution

The correct option is 2 and 3 only.

Explanation

The heating of the atmosphere involves four primary processes: radiation (incoming solar and outgoing terrestrial), conduction, convection, and advection. The lower atmosphere is primarily heated by the earth's surface through longwave terrestrial radiation and direct contact mechanisms like conduction and convection.

Statement-wise Analysis

Statement 1 is Incorrect: Conduction is the process where heat flows from a warmer object to a cooler object when they are in contact. For the atmosphere, the air touching the warm earth is heated by conduction. Standard physical geography texts explicitly state that conduction is important in heating the lower layers of the atmosphere. Therefore, labeling it as the "least important" process for the lower layers is factually incorrect.
Statement 2 is Correct: Air is a known poor conductor of heat (an insulator). Consequently, the transfer of heat from the land surface to the air in contact with it occurs relatively slowly compared to other modes of heat transfer like convection or radiation.
Statement 3 is Correct: According to the principles of atmospheric heating, the layer of air immediately in contact with the ground gets heated first. This layer then transfers heat to the adjacent upper layers through contact. This specific layer-to-layer transfer mechanism is defined as conduction, even though convection becomes the dominant force for vertical mixing once the air becomes buoyant.

Key Takeaway

Conduction is the primary mechanism for heating the thin layer of air directly in contact with the earth's surface. Convection is responsible for the vertical transport of this heat into the upper atmosphere, while Advection handles horizontal heat transfer.

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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Which of the following is a characteristic of the isotherms in the Southern Hemisphere?

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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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Which of the following is defined as "the energy needed to raise the temperature of one gram of substance by one Celsius"?

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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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