Geography – Topic 1 Hazardous Earth
Ayla Maydanchi
GCSE Revision
, The Global Atmospheric Circulation
The Earth’s atmosphere is constantly moving, forming global circulation
patterns over time, involving three cells in each hemisphere.
Geography – Topic 1 – Hazardous Earth
Thicker atmosphere
for air to get through
Hadley Cell : Warm air, at equator, rises into upper atmosphere, cools as it
moves away, meaning it descends at tropics.
Ferrell Cell : Cold air from poles meets warm air from tropics in mid
latitudes.
Polar Cell : Cold air descends at poles, then moves away to mid latitudes 1
, Atmospheric Pressure
Atmospheric Pressure : This is the ‘weight’ of air and the force this puts on
the ground.
Geography – Topic 1 – Hazardous Earth
Warmth of Earth’s surface heats
Air Sinking ‘Weight’ of sinking air
the air above, providing it with
puts more pressure on
enough energy to rise. Less Air rises, moving away from
the ground = area of
pressure on the ground as air Earth’s surface, so air begins
high pressure
rises = area of low pressure to cool. Cooler air has less
Low Pressure energy so it sinks back down. High Pressure 2
Ayla Maydanchi
GCSE Revision
, The Global Atmospheric Circulation
The Earth’s atmosphere is constantly moving, forming global circulation
patterns over time, involving three cells in each hemisphere.
Geography – Topic 1 – Hazardous Earth
Thicker atmosphere
for air to get through
Hadley Cell : Warm air, at equator, rises into upper atmosphere, cools as it
moves away, meaning it descends at tropics.
Ferrell Cell : Cold air from poles meets warm air from tropics in mid
latitudes.
Polar Cell : Cold air descends at poles, then moves away to mid latitudes 1
, Atmospheric Pressure
Atmospheric Pressure : This is the ‘weight’ of air and the force this puts on
the ground.
Geography – Topic 1 – Hazardous Earth
Warmth of Earth’s surface heats
Air Sinking ‘Weight’ of sinking air
the air above, providing it with
puts more pressure on
enough energy to rise. Less Air rises, moving away from
the ground = area of
pressure on the ground as air Earth’s surface, so air begins
high pressure
rises = area of low pressure to cool. Cooler air has less
Low Pressure energy so it sinks back down. High Pressure 2
