GCSE Geography B Edexcel

Global Atmospheric Circulation

Global Atmospheric Circulation

Global atmospheric circulation describes the movement of the air around the Earth. It's a critical aspect of the Earth's weather and climate, and influences hazardous weather events. Here are key points to remember:

What it is

• Global atmospheric circulation is the large-scale movement of air, fueled by the heat energy from the Sun.
• It is part of what determines the climate in different parts of the world.

How it works

• The equator receives the most sunlight. As the air heats up, it rises, creating a low pressure zone.
• When the warm air rises, it cools and condenses, forming clouds and rain. This creates tropical climates at the equator.
• The cool air moves towards the poles, sinking at around 30 degrees from the equator. This sinking creates areas of high pressure and often results in desert climates.
• The air near the ground then flows back towards the equator, starting the cycle over again.
• Hadley cells, Ferrel cells, and Polar cells are the three convection cells that exist in each hemisphere, named for the regions they cover.

Why it's important for the climate

• The global atmospheric circulation model influences where different types of weather occur.
• It determines periods of rainfall and dry weather over the Earth.

How it affects hazardous Earth events

• It is important for understanding natural hazards such as tropical storms.
• It plays a role in the formation and intensity of monsoons in Asia.
• The pattern changes can lead to extreme weather events like droughts, floods, and heatwaves.

Impact of Global Warming

• Global warming could potentially disrupt atmospheric circulation patterns.
• Changes to the global atmospheric circulation could lead to altered weather patterns, impacting local climates.