Question

seventy - five percent of the worlds tornadoes occur in the united states during the late spring and early summer months, when warm moist air from the tropics rises to meet cold air descending from canada. as the warm tropical air rises, it condenses quickly into cumulus clouds. cumulus clouds can then evolve into cumulonimbus clouds, which eventually can form super cells (thunderstorms). wind moving in various directions causes the condensing air to spin like a top. if the resulting funnel is able to stretch between the bottom of the cloud and the ground, it becomes a tornado. which of the following would increase the intensity of the tornado? a. increased rate of evaporation b. decrease in condensation c. increase of cold air d. decrease in wind speed

Explanation:

To determine what increases tornado intensity, we analyze each option:

• Option A: Increased evaporation provides more warm, moist air. This air rises, condenses (fueling cloud development and storm energy), so more evaporation would increase tornado intensity.
• Option B: Decreased condensation reduces cloud/storm energy, weakening the tornado.
• Option C: More cold air would stabilize the atmosphere, reducing the upward movement of warm air needed for tornado formation.
• Option D: Decreased wind speed reduces the spinning motion (vorticity) needed for tornado development.

Answer:

A. increased rate of evaporation