Question

Earth has hot, dry regions and cool, wet regions. How does convection contribute to the distribution of heat and moisture across Earth?

A.
Convection allows the transfer of energy directly from the sun to Earth's surface.

B.
Convection causes the water vapor in the atmosphere to absorb the energy from cooler air masses all over Earth.

C.
Convection causes air masses carrying water and energy as heat to rise and fall, all over Earth

D.
Convection distributes energy as heat throughout Earth's solid crust, warming the entire planet.

Answer 1

Answer: C.

Convection is the vertical movement of air: warm, moist air rises (cools and often precipitates), and cool, dry air sinks (warms and dries). Those rising and sinking motions form large-scale circulation cells that redistribute heat and moisture around the planet (e.g., the rainy equatorial ITCZ and the dry subtropical highs).

Why the others are wrong:
- A describes radiation, not convection.
- B is incorrect in mechanism and wording — convection moves air masses; water vapor absorbs radiation and thermal energy but not “from cooler air masses all over Earth.”
- D describes heat in the solid Earth (conduction/geothermal), not atmospheric convection.