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
Explanation
Correct Answer: (a) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
- Statement-I: The thickness of the troposphere at the equator is much greater as compared to the poles.
- This statement is correct. The troposphere is thicker at the equator due to higher temperatures, which cause thermal expansion and stronger convectional currents that push the troposphere to greater heights.
- Statement-II: At the equator, heat is transported to great heights by strong convectional currents.
- This statement is correct. The equator receives more solar radiation, leading to higher temperatures and stronger convectional currents that transport heat to higher altitudes.
- Explanation: Statement-II explains Statement-I because the strong convectional currents at the equator, driven by higher temperatures, result in the expansion of the troposphere, making it thicker at the equator compared to the poles.
Learn more
- Troposphere: The troposphere is the lowest layer of Earth’s atmosphere, extending from the surface to an average height of about 8 km at the poles and 18 km at the equator.
- Thermal Expansion: The equator is warmer, causing the air to expand and rise, leading to a thicker troposphere.
- Convectional Currents: Strong convectional currents at the equator transport heat to great heights, contributing to the increased thickness of the troposphere.
- Centrifugal Force: The Earth’s rotation causes a centrifugal force that is strongest at the equator, pushing the atmosphere to greater heights.
- Seasonal Variation: The thickness of the troposphere varies with the seasons, being thicker in the summer and thinner in the winter.
- Gravitational Pull: The gravitational pull is stronger at the poles, leading to a contraction of the atmosphere and a thinner troposphere.
These factors collectively explain why the troposphere is thicker at the equator than at the poles.
