Wind
• the movement of air by differences in air
pressure
• Air moves from areas of high pressure to areas
of low pressure
• Air moves in small circular patterns called
convection currents.
The Coriolis Effect
• the apparent curve of the wind due to the
rotation of the Earth
Global Winds
• wind systems that occur at or near the Earth’s
surface
• Three types
– Polar easterlies
– Prevailing Westerlies
– Trade winds
Polar Easterlies
•
•
•
•
Cold winds
From the east
Snow and freezing weather
60° - 90°
Prevailing Westerlies
• From the west
• Our winds
• Moist air – rain/snow
• 30° - 60°
Horse latitudes
• 30° N and S
• Calm winds
Trade Winds
•
•
•
•
From the east
Steady winds
Reliable winds
Sailors used them for trading between Europe
and America
Doldrums
• 0°
• At the equator
• Calm winds
Jet Stream
• narrow belts of high-speed winds that blow
form west to east high in Earth’s atmosphere
• Two types
– Polar
– Subtropical