GLOBAL ATMOSPHERIC CIRCULATION

PRERNA FOR IAS

GLOBAL ATMOSPHERIC CIRCULATION

(GEOGRAPHY)

1. Global Atmospheric Circulation

Global atmospheric circulation is the large-scale movement of air around the Earth that helps distribute heat from the Equator to the poles. It is driven by unequal solar heating, Earth's rotation, and pressure differences. This circulation creates major wind belts, pressure zones, and weather patterns across the globe. The system consists of three circulation cells in each hemisphere: the Hadley Cell, Ferrel Cell, and Polar Cell. These cells regulate climate, rainfall, storms, and temperature distribution. Global atmospheric circulation is essential for maintaining Earth's energy balance and plays a key role in shaping regional and global weather systems.

2. Hadley Cell

The Hadley Cell is the tropical atmospheric circulation system located between the Equator and about 30° latitude in both hemispheres. Warm air rises near the Equator due to intense solar heating, creating a low-pressure zone. 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 then flows back toward the Equator as trade winds, completing the circulation cycle. The Hadley Cell is responsible for tropical rainforests near the Equator and desert regions around 30° latitude, including the Sahara Desert.

3. Ferrel Cell

The Ferrel Cell is located between approximately 30° and 60° latitude i