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?

Answer: (a) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I

The troposphere is ~18 km thick at the equator vs ~8 km at the poles, because strong convection carries heat high.

The idea

The tropopause is the upper boundary of the weather-producing troposphere. It is higher where air is warm and convection transports heat to greater heights. Cold polar air has weaker convection and a lower tropopause. Density alone does not tell us how high the weather layer extends.

Tropical surface receives strong heating → Air warms and expands → Convection develops → Heat is carried to greater heights → The tropopause lies higher than over the poles

Why the others are wrong

(b) II is the reason for I.

(c) II is true.

(d) I is true.

Also know

The troposphere contains most atmospheric water vapour. Above it, the stratosphere is more stable and warms upward as ozone absorbs ultraviolet light. A tropopause height is an approximate regional value, not a fixed worldwide ceiling. Tropical thunderstorms can sometimes overshoot the local tropopause.