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?

The correct option is: Both Statement-I and Statement-II are correct and Statement-II explains Statement-I.

To understand why this is correct, let us analyze each statement individually and examine the connection between them:

Analysis of Statement-I:
The troposphere is the lowest layer of Earth's atmosphere where almost all weather phenomena occur. The thickness (or height) of the troposphere is not uniform across the globe. It is deepest at the equator, reaching heights of up to 18 km, whereas at the poles, it extends only to about 8 km. Therefore, Statement-I is correct.

Analysis of Statement-II:
The equator receives intense, direct solar radiation throughout the year, leading to high surface temperatures. This heating causes the air near the surface to expand, become less dense, and rise rapidly. This upward movement of air creates strong vertical convection currents that transport heat and moisture to great heights in the atmosphere. Therefore, Statement-II is correct.

Relation between Statement-I and Statement-II:
The primary reason the troposphere is pushed much higher at the equator compared to the poles is precisely due to this intense convective heating. The strong convection currents at the equator actively loft the warm air upward, stretching the troposphere vertically. Conversely, at the poles, cold temperatures and sinking air compress the troposphere. Since Statement-II provides the direct physical mechanism behind the observation in Statement-I, Statement-II is the correct explanation for Statement-I.