1. Wind

2. Wind The Earth is in a constant battle to equalize its temperature
It never succeeds, because our planet is hotter in some places than in others

3. Wind Patterns Earth’s air is always on the move
Cool air sinks
Warm air rises
Forms convection currents

5. Wind Wind is the movement of air as a result of different air pressure
The greater the pressure difference, the stronger the wind
Caused by unequal heating of the Earth

6. Pressure Belts

7. Coriolis effect Global winds do not blow in straight lines
Coriolis Animation
Global winds do not blow in straight lines
The earth rotates as wind blows, making it seem as if the winds are curving
Called the Coriolis effect

8. Coriolis Effect
The wind blows in a curved path due to the rotation of the Earth
Northern Hemisphere - winds curve to the right
Southern Hemisphere - winds curve to the left
Coriolis Effect
Winds and the Coriolis Effect

9. Kinds of Winds
Local winds- generally move short distances and can blow from any direction
Global winds- are part of a pattern of air flow that moves across the Earth

10. Local Winds
Land breezes and sea breezes occur because of the differences in heat of the land and the water
These differences create a convection current

11. Air Cools Down
Cold Air Sinks
Wind Blows Toward Coast
Warm Air Rises
Sea Breeze
During the day, the land heats up more quickly than the sea. Above the land, warm air rises and the wind blows toward the coast.
Warm Air Rises
Cold Air Sinks
Air Cools Down
Wind Blows Away from the Coast
Land Breeze
At night, the land cools down quickly while the sea stays warm. Above the sea, warm air rises and the wind blows away from the coast.

12. During the Day

14. At Night

15. L L H H Local Ocean Effects
Sea Breeze happens during the day when the land heats up more than the ocean
Land Breeze happens during the night when the land cools off more than the ocean

19. Global Wind Patterns Winds carry heat north from Earth’s equator
Winds carry colder air south toward the equator

20. Global Winds
Coriolis and other factors combine to produce a pattern of wind belts around the earth
Major wind belts:
Trade winds
Westerlies
Easterlies

21. Trade Winds
Blow at 30* latitude to the equator. (early sailors used the winds to sail from Europe to America)
When cold air sinks, produces high pressure
High pressure wants to move to an area of low pressure--the equator!!
These winds that are blowing toward the equator are deflected west because of the coriolis effect

22. Westerlies Between 30* and 60* latitude Flows towards the poles
Helped ships return to Europe.
Turned toward the east by Coriolils effect
Blow from west to east-- WESTERLIES

23. Easterlies Between the poles and 60* latitude.
Cold air near poles sinks and flows back toward lower latitudes
Coriolis shifts these winds to west
Wind goes from East to west-- EASTERLIES

24. Columbus and Global Scale Winds
Columbus was an expert sailor with a extraordinary knowledge of the global winds. He did not attempt to sail into the teeth of the westerly winds, but rather turned south and used the Easterly Trade Winds to drive his ships across the Ocean. On the return voyage, he headed north and then used the westerlies to propel his ships back to Europe, stopping at the Azores on the way for much needed repairs.

25. Doldrums Near equator, between 0-30 degrees latitude
Rising air, low pressure
Cool air moves into area, warmed rapidly, and rises
Warms so fast, air doesn’t have an opportunity to move very far before it rises again.
Winds very weak near equator- DOLDRUMS

26. Doldrums
All in a hot and copper sky, The bloody Sun, at noon, Right up above the mast did stand, No bigger than the Moon.
Day after day, day after day, We stuck, nor breath nor motion; As idle as a painted ship Upon a painted ocean.
- The Ancient Mariner

27. Horse Latitudes Between about 30° to 35° north and 30° to 35° south
Latitude and Precipitation
Between about 30° to 35° north and 30° to 35° south
Weak winds
Forms a belt of calm air
Contributes to deserts in this area

28. Prevailing Wind Patterns

29. Global Wind Pattern
Global Wind Patterns

31. Rainforests of the World
Most rainforests are near the equator because this is where the air is rising, creating clouds and rain.

32. Deserts of the World
Most deserts are at 30o
N and S Latitude because the air is sinking, drying it out.

33. MoreDirect Sun Hot 0 o Equator 30 o S 60 o S 90 o S 30 o N 60 o N