Global Atmospheric Circulation | AQA GCSE Geography | Weather Hazards 1

This revision video explains what global atmospheric circulation is, looking at the Hadley, Ferrel and Polar cells and how they influence our weather.

It is part of the AQA GCSE Geography course - Paper 1: Unit A - The Challenge of Natural Hazards.

Hadley, Ferrel, and Polar cells refer to the three primary circulation cells in Earth's atmosphere, which transport heat and moisture around the planet and influence global weather patterns. Here are some details:

Hadley cell

• Named after George Hadley, who first described it in the 18th century
• Extends from the equator to about 30 degrees latitude
• Characterized by rising air at the equator, which cools and condenses to form clouds and precipitation
• Air then diverges, moves poleward at high altitudes, descends and warms in the subtropics, creating a band of dry, sinking air called the subtropical high
• The Hadley cell influences weather patterns such as monsoons, deserts, and tropical storms.

Ferrel cell

• Named after William Ferrel, who described it in the 19th century
• Extends from 30 to 60 degrees latitude
• Characterized by cool, dry air descending from the polar cell, colliding with warm, moist air from the Hadley cell
• Creates mid-latitude weather patterns such as cyclones, anticyclones, and frontal systems
• Influences weather in regions like North America, Europe, and East Asia.

Polar cell

• Located at high latitudes, above 60 degrees
• Driven by cold, dense air that sinks from the stratosphere and flows towards the poles
• Creates a circulation of frigid, dry air that influences polar climates and weather
• Interacts with the Ferrel cell to produce weather systems such as blizzards, polar lows, and polar fronts.

These cells interact and overlap, with their strengths varying based on season, location, and other factors. They are part of the large-scale atmospheric circulation, which drives weather patterns, heat, and moisture transport across the globe.