Winds 1. Why does air move? •  Air pressure differences causes air to move •  Air moves from high pressure to low pressure. 2. What does this mean globally? Cool air from the poles moves in the direc=on of the Equator, but not in a giant circle. 3. What are pressure belts? •  Warm air cools as it rises and starts sinking. •  This causes pressure belts: –  Cycles of high and low pressure between Equator and poles. Local Winds •  Local Winds: Winds that directly affect a specific area –  Local winds are different from global winds. •  They are influenced by the geography of an area, such as shorelines and mountains. •  Examples: –  Sea and land breezes
–  Mountain and valley breezes Five Types of Global Winds •  5 types of Global Winds –  Trade Winds –  The Doldrums and Horse La=tudes –  Westerlies –  Polar Easterlies –  Jet Stream 4. What are the trade winds? •  Trade Winds: Winds that blow from 30° la=tude to the Equator. ←
Trade Winds
←
Trade Winds
5. What are the Doldrums? •  Doldrums: low pressure at Equator where trade winds meet. LiXle winds here. ← Trade Winds
← Doldrums
← Trade Winds
6. What are horse La=tudes? •  The Horse La8tudes: areas of high pressure at 30°N and 30°S where cool air is sinking. Weak winds! Horse Latitudes →
Trade Winds →
Trade Winds →
Horse Latitudes →
7. What are the westerlies? •  Westerlies: Wind belts between 30° and 60° la=tudes that flow towards the poles ← Westerlies
← Westerlies
8. What are the Polar Easterlies? •  Polar Easterlies: Cold, sinking air from the poles that moves towards the 60° la=tudes ← Polar
Easterlies
← Polar
Easterlies
Jet Stream •  Jet Stream: Narrow belts of high-­‐speed winds that blow from the upper part of our sky ← Jet Streams
← Jet Streams