GLOBAL ATMOSPHERIC CIRCULATION

PRERNA FOR IAS

GLOBAL ATMOSPHERIC CIRCULATION

1. Hadley Cell

The Hadley Cell is a major atmospheric circulation cell located between the Equator and 30° latitude in both hemispheres. Intense solar heating at the Equator causes warm, moist air to rise, creating a low-pressure zone known as the Intertropical Convergence Zone (ITCZ). As the air rises, it cools and moves poleward at high altitudes. Around 30° latitude, the air descends, forming subtropical high-pressure belts. The descending air returns toward the Equator as trade winds, completing the circulation cycle. The Hadley Cell influences tropical rainfall, monsoon systems, and the formation of major desert regions around the world.

2. Ferrel Cell

The Ferrel Cell is the middle atmospheric circulation cell found between 30° and 60° latitudes in both hemispheres. It acts as a transition zone between the Hadley Cell and the Polar Cell. Surface winds in this region move toward the poles and are deflected by Earth’s rotation, forming the westerlies. Warm air from lower latitudes meets cold polar air near 60°, causing uplift and low-pressure conditions. The Ferrel Cell plays a significant role in generating temperate weather systems, cyclones, and rainfall. It is responsible for much of the changing weather experienced in mid-latitude regions worldwide.

3. Polar Cell