1. Winds
Energy From the Sun

2. The atmosphere is the mixture of gases that surrounds the Earth
The atmosphere is the mixture of gases that surrounds the Earth. It is divided into 4 layers classified by temperature.

3. Energy in the Atmosphere
energy in Earth’s atmosphere comes from the sun
energy travels as electromagnetic waves
Most of the energy is in the form of visible light and infrared radiation
A small amount of ultraviolet radiation

4. Electromagnetic Energy
Different forms of electromagnetic energy have different wavelengths.
Examples of electromagnetic energy are:
microwaves
infrared light
visible light
ultraviolet light
X-rays
gamma rays.

5. Visible light Mixture of colors (ROYGBIV)
Different colors result of different wavelengths

6. Infrared Radiation Wavelengths LONGER than red light Not visible
Felt as heat

7. Ultraviolet radiation
Wavelengths that are SHORTER than violet light
Not visible
Causes sunburns, eye damage, skin cancer
Ozone in the stratosphere blocks most of the UV radiation

8. Heating of the atmosphere
Some of the energy is reflected/absorbed in the atmosphere
The rest is reflected/absorbed by the surface.
The greenhouse effect is a natural process by which gases hold heat in the air warming our planet.

9. Heat Energy
Thermal energy is the total energy of motion in the molecules of a substance.
“Heat" is used when energy is transferred from one substance to another.

10. Heat Energy Moves
Heat moves from warmer objects to cooler ones until they reach the same temperature.

11. Heat Energy Moves Heat can be transferred through:
Transfer of heat by direct contact (conduction)
Transfer by electromagnetic waves (radiation.)
In a liquid or gas, currents will cause the transfer of heat (convection.)

13. Heat Moves Through the Atmosphere
Convection causes most of the heating of the troposphere.
The upward movement of warm air and the downward movement of cool air form convection currents.
These currents cause wind.

14. What is wind? Warm air expands and rises creating low pressure.
Cold air sinks and creates high pressure.
Winds are caused by differences in air pressure.
Winds move from high to low pressure.

15. Summary
Heating of Earth’s surface and atmosphere by the Sun drives convection within the atmosphere producing winds.

16. Local winds winds that blow over short distances Sea and land breezes
Unequal heating results in differences in pressures causing winds to blow

17. Sea/lake and land breezes

18. Global winds
Winds that blow steadily from specific directions over long distances
Temperature differences between the equator and the poles creates giant convection currents

19. Coriolis Effect Global winds do NOT blow in a straight line
The Earth’s rotation causes the global winds to curve

20. Major Global Wind Belts
Trade winds
Prevailing westerlies
Polar easterlies

21. Horse Latitudes and Doldrums
Areas of little to no wind

22. Animation of global wind belts