Why is the troposphere higher over the equator?

Correct answer: Because strong heating and convection are greater there

Direct answer: The troposphere is higher over the equator because stronger solar heating produces stronger convection, so option B is correct. The equatorial surface receives more direct sunlight on average. This warms the ground and the air above it. Warm air expands, becomes less dense, and rises. Continuous rising and mixing are called convection. These stronger vertical motions extend the troposphere to a greater height than in colder polar regions. Option A is wrong because the equator is not colder; it receives intense heating. Option C is wrong because the equatorial region has abundant air. Option D is wrong because ozone is not the main reason for the height difference. The important chain is: stronger sunlight → warmer air → expansion and rising → stronger convection → a higher tropopause. Memory cue: “More heat makes air rise higher.”