Q. 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?
(a) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
(b) Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
(c) Statement-I is correct, but Statement-II is incorrect
(d) Statement-I is incorrect, but Statement-II is correct
Correct answer: (a) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
Question from UPSC Prelims 2024 GS Paper
Explanation:
Statement-I: “Thickness of the troposphere at the equator is much greater as compared to poles.”
This statement is correct. The troposphere, which is the lowest layer of Earth’s atmosphere, is indeed thicker at the equator (about 16-18 km) compared to the poles (about 8-10 km).
Statement-II: “At the equator, heat is transported to great heights by strong convectional currents.”
This statement is also correct. The equatorial regions receive more direct sunlight, causing intense heating of the surface. This leads to strong convection currents that carry heat and moisture to higher altitudes in the atmosphere.
Now, let’s consider the relationship between these statements:
Statement-II actually explains why Statement-I is true. The strong convectional currents at the equator transport heat to greater heights, which effectively pushes the boundary of the troposphere higher. This is why the troposphere is thicker at the equator compared to the poles, where such strong convection doesn’t occur.