1. Global Winds

2. What is wind?
Wind is the movement of air caused by an uneven heating of the Earth’s surface.

3. What HEATS EARTH’S SURFACE?
Heat from the sun heats the surface of the Earth.
This heat arrives to Earth in the form of radiation.
Radiation is the transfer of energy by electromagnetic waves.
Radiation can transfer heat without direct contact between objects.
Solar radiation originates from the sun.

4. Convection cells
Winds do not travel straight from the equator to poles.
Due to the cycling of hot, low pressure and less dense air with cold, high pressure, more dense air, wind travels via convection cells.
Convection cells are:
Pockets of cycling warm, less dense, low pressure air with cool, denser high-pressure air.
Pressure difference results in global movement of air.

5. What are global winds?
Global winds are winds that are produced by the movement of air between the equator and the poles.

6. Westerlies (prevailing) Trade winds Doldrums Horse Latitudes
Major global winds
Polar Easterlies
Westerlies (prevailing)
Trade winds
Doldrums
Horse Latitudes

7. Doldrums
Little or low wind area near the equator where warm air rises.
In addition to reading what doldrums are, the teacher can point to the pink arrows that show the location of doldrums. Teacher can also locate supplemental information on doldrums to share with students if desired.

8. Trade winds
Winds that blow from the horse latitudes toward the equator.
In addition to reading what trade winds are, the teacher can point to the pink arrows that show the location of trade winds. Teacher can also locate supplemental information on trade winds to share with students if desired (such as how these winds affected trading by sea).

9. Horse latitudes Little or low wind area where air is falling.
Found at 30 degrees latitude.
In addition to reading what horse latitudes are, the teacher can point to the pink arrows that show the location of horse latitudes. Teacher can also locate supplemental information on horse latitudes to share with students if desired (such as the fact that these latitudes were named because this is where horses were thrown into the sea).

10. Westerlies (prevailing)
Winds that blow from the west to the east.
Found between 30 and 60 degree latitudes.
In addition to reading what prevailing westerlies are, the teacher can point to the pink arrows that show the location of prevailing westerlies. Teacher can also locate supplemental information on prevailing westerlies to share with students if desired (such as the effect these winds have on weather).

11. Polar Easterlies Winds that blow away from the poles.
Blows from east to west.
Found between the poles and 60 degrees latitude.
In addition to reading what polar easterlies are, the teacher can point to the pink arrows that show the location of polar easterlies. Teacher can also locate supplemental information on polar easterlies to share with students if desired (such as the effect these winds have on weather).