1. Today’s Agenda…11-14  Bellringer: What causes winds?
Wrap up Air Movement Notes and Discussion
Notes on Earth’s Atmosphere
Test on Wednesday

2. Earth’s Atmosphere
Study Pack #11

3. Today’s Goals…
I can describe the layers of the Earth’s atmosphere.

4. Atmosphere
Thin layer of air that forms a protective covering around the planet
What would happen if Earth did not have an atmosphere?
Maintains a balance of heat on Earth
Protects life forms from the sun’s harmful rays

5. Atmosphere Mixture of gases, solids, liquids
Nitrogen is the most abundant gas
Oxygen, argon, carbon dioxide
Page 91

6. Atmosphere Layers: Troposphere Stratosphere Mesosphere Thermosphere
Exosphere

7. Troposphere Lowest of Earth’s atmospheric layers The layer you live in
Extends up 10 km
Rain, snow, and clouds occur here

8. Stratosphere 10 – 50 km up Contains the ozone layer
Shields your from harmful UV rays

9. Mesosphere
50 – 85 km
You may see shooting stars in the mesosphere

10. Thermosphere 85 – 500 km Very high temperatures
In the mesosphere and thermosphere is the ionosphere
A layer of electrically charged particles
Allows AM radio waves to travel across the country

11. Exosphere
Space shuttles orbit in the exosphere

12. Atmospheric Pressure
Atmospheric gases extend hundreds of kilometers above Earth’s surface
The force of gravity pulls these gases downward which causes them to press down on the gases below
Air pressure is greater near Earth’s surfaces and decreases higher in the atmosphere

13. Atmospheric Pressure
Why is it difficult to breath as you go higher into the atmosphere?
The air is less dense (less pressure)
There are fewer molecules of air (page 94)
Applying Science

14. Temperature in the Atmosphere
Figure 8, page 95
The layers of the atmosphere are based mainly on differences in temperature

15. Temperature in the Atmosphere