1. The Atmosphere
Ch. 3 sec. 2

2. atmosphere
Mixture of gases surrounding the Earth

3. Atmosphere 78% nitrogen 21% oxygen
1% other (argon, carbon dioxide, methane, and water vapor)

4. Where do gases come from
Animals – cellular respiration
Plants - Photosynthesis

5. Where do gases come from
Volcanic eruptions
Vehicles
industries

6. Particles in the Atmosphere
Atmospheric dust – salt, ash from fires, volcanic ash, skin, hair, pollen, bacteria, viruses

7. Insulation Atmosphere insulates the Earth Slows the loss of heat
Maintains temp.

8. Layers of Atmosphere
Troposphere
Stratosphere
Mesosphere
Thermosphere

9. Troposphere Nearest to the Earth Weather occurs in this layer
Densest layer

10. Stratosphere Extends from 18km to 50km Temp. rises
Ozone layer – O3 (absorbs UV rays)

11. Mesosphere
50Km -80Km
Coldest layer

12. Thermosphere Farthest from Earth
Hottest layer (nitrogen and oxygen absorb solar radiation)

13. Aurora - Northern lights
Nitrogen and Oxygen atoms absorb X rays and gamma rays
Causes them to become charged (ions)

14. Energy in the Atmosphere
Energy from sun is transferred:
Radiation
Conduction
Convection

15. Radiation
Transfer of energy in the atmosphere
Standing by a fire

16. Conduction
Flow of heat from a warmer object to a colder object by direct contact
Pan on a stove

17. Convection Transfer of heat by air currents
Convection oven, heater in house/car

18. Heating of Atmosphere
Half of solar energy that enters the atmosphere passes through and reaches Earth’s surface
Absorbed or reflected by clouds, gases

19. Heating of Atmosphere
Oceans and land radiate energy back into atmosphere

20. Heating of atmosphere
Darker objects absorb more solar radiation than lighter objects

21. Movement of energy Air movements cause our weather
Warm air rises and cold air sinks

22. Convection Currents
The continual process of warm air rising and cool air sinking in a circular motion is called Convection Currents

23. Greenhouse Gases
Gases in the air trap heat that is being reflected back from the Earth
Heat is absorbed which warms the air