What can start convectional rainfall?

Correct answer: Strong heating of the ground

Correct answer: A, strong heating of the ground. In convectional rainfall, the surface is heated strongly, usually by the Sun. The air touching the warm ground is warmed, becomes less dense than the surrounding air, and rises. As it rises, it expands and cools. If enough moisture is present, the water vapour condenses into clouds; continued uplift and condensation can produce showers. B is not the starting mechanism because pressing ice into the ground does not heat moist air and create convection. C is not a real atmospheric cause of rainfall. D is incorrect because convection requires air movement; complete absence of air cannot produce rising air currents. A is correct because surface heating starts the upward movement that gives this rainfall its name. Convection means vertical movement caused by differences in heating and density. Memory cue: “hot ground, rising air, cooling clouds, convectional rain.”