Consider the following statements :

Statement-I: Thickness of the troposphere at the equator is much greater as compared to poles.

Statement II: At the equator, heat is transported to great heights by strong convectional currents.

Which one of the following is correct in respect of the above statements?

Question

Question

This question was previously asked in

UPSC CSE Prelims 2024: General Studies Official Paper

Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
Statement-I is correct, but Statement-II is incorrect
Statement-I is incorrect, but Statement-II is correct

Answer 1

The correct answer is Option 1.

Key Points

Statement-I: Thickness of the troposphere at the equator is much greater as compared to poles.

Troposphere Thickness: The troposphere is the lowest layer of Earth's atmosphere, where most weather phenomena occur. Its thickness varies from about 8 km at the poles to about 18 km at the equator. Hence, statement 1 is correct.
Reasons for Variation:
- Temperature: The equator receives more direct solar radiation, leading to higher surface temperatures. This causes the air to warm up, expand, and rise to greater heights.
- Convection: Strong convection currents at the equator push the warm air higher, increasing the troposphere's thickness.

Statement II: At the equator, heat is transported to great heights by strong convectional currents.

Strong convectional currents at the equator transport heat to great heights, explaining the greater thickness of the troposphere in this region. Hence statement 2 is correct.
- Convectional Currents: Convection is the process by which warm air rises and cool air sinks, creating a circulation pattern. At the equator, the intense solar heating causes strong convectional currents.
- Heat Transport: These strong convection currents transport heat from the surface to higher altitudes, contributing to the greater thickness of the troposphere in equatorial regions.
Statement-II is the correct explanation for Statement-I: The strong convectional currents that transport heat to great heights at the equator are the reason for the greater thickness of the troposphere in this region.
Therefore, the correct option is that both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I.