Global Winds
Global winds- winds that blow
steadily from specific directions
over long distances.
Major global wind belts
1. Trade winds
2. Polar easterlies
3. Prevailing westerlies
Image on p. 51
Global Winds
Doldrums
• Direct sun rays hit equator and strongly heats Earth’s surface
• Warm air will ______ (rise or sink) creating ______ (high or low)
pressure.
• Cool air moves in but is warmed rapidly
• Little horizontal motion so winds near equator are weak
Horse Latitudes
• Latitude- distance from equator measured in degrees
• ~30 N and S latitudes, the air stops moving toward poles and sinks
creating a belt of air
• How did this wind belt get its name “Horse Latitudes”?
 Write a sentence in your own words.
Global Winds
Trade Winds
• Between 30 L and the equator in both hemispheres
• Rotation of Earth causes trade wind to curve west
• Named because sailors relied on them to sail from Europe to
Americas
Westerlies
• Between 30 and 60 L in both hemispheres.
• Rotation of Earth causes wind to curve east
• Can carry moist air over the U.S. producing rain and snow
Global Winds
Polar Easterlies
• Between poles and 60 L in both hemispheres
• Rotation of Earth causes winds to curve west
• Can carry cold Arctic air over most of U.S. producing snow and
freezing weather.