In the global three-cell circulation, air tends to rise around the equator and sink at the subtropics.

In the global three-cell circulation, air tends to rise around the equator and sink at the subtropics.

• A. Rise at the equator; Sink at the subtropics
• B. Rise at the subtropics; Sink at the equator
• C. Rise at the poles; Sink at the equator
• D. Sink at the poles; Rise at the equator

Answer: (A)

Air rises where heating is strongest and sinks where it is weaker and cooler. In the global three-cell circulation, this happens most clearly in the Hadley cell near the equator: intense solar heating causes warm air to rise, creating the Intertropical Convergence Zone with frequent rain. As the air rises and moves poleward aloft, it cools and eventually sinks around the subtropics (around 30° latitude), forming the subtropical high-pressure belts. This sinking motion at the subtropics completes the circulation loop and sets up surface trade winds flowing back toward the equator. So the best description is that air rises at the equator and sinks at the subtropics.

Air rises where heating is strongest and sinks where it is weaker and cooler. In the global three-cell circulation, this happens most clearly in the Hadley cell near the equator: intense solar heating causes warm air to rise, creating the Intertropical Convergence Zone with frequent rain. As the air rises and moves poleward aloft, it cools and eventually sinks around the subtropics (around 30° latitude), forming the subtropical high-pressure belts. This sinking motion at the subtropics completes the circulation loop and sets up surface trade winds flowing back toward the equator. So the best description is that air rises at the equator and sinks at the subtropics.