1. Get out your notebooks for notes
Bell Work
Get out your notebooks for notes
What do we mean when we talk about our atmosphere?
How high up into the sky does the our atmosphere go?
What is our atmosphere made up of?

2. Atmosphere - 1

3. What is The Atmosphere? Atmo (vapor or air) + sphere (orb)
Layer of gases surrounding Earth
Where weather occurs
Essential for life
Keeps Earth warm

4. Contents of our air:
Argon 0.9%
CO2 0.03%
Other ~0.07%
O2 21%
Nitrogen
78%

5. Oxygen: All living organisms require
Carbon Dioxide: Required for photosynthesis; keeps the Earth warm
photosynthesis

6. Nitrogen: All living organisms need for proteins & DNA; the atmosphere is Earth’s nitrogen reservoir

7. Other components in the air:
1. Water Vapor
Occurs as clouds.
Absorbs solar energy.

8. 2. Ozone Layer: Made up of O3 molecules 10-50 km above Earth
Absorbs harmful UV radiation
Without CO2 and ozone the average temperature on Earth would be -6o C

9. 3. Atmospheric Solids
Salt from sea spray and dust
Condensation nuclei: form when dust & salt attract water vapor; leads to clouds, hail & snow formation

10. Heat on Earth comes from solar radiation that is …
Absorbed by Earth
Scattered back to Earth by CO2, H2O, and other gases in the air

11. Layers of the Atmosphere
Characterized by distance from Earth & temperature
Further from Earth, there are fewer molecules in the air – pressure ↓, the air is “thinner”

12. Troposphere To ~16 km high Temp. ↓ with distance above Earth
Most weather happens here
Most pollution is trapped here

13. Stratosphere From 16 - 50 km Most ozone is here
Temp. ↑ with height because of ozone
Very little water vapor

14. Mesosphere From 50-80km Temp. ↓ as you rise No Ozone
Very thin air (few molecules)

15. Thermosphere Beyond 80 km
Temp. ↑ with height (more solar rays absorbed)
Air very thin – won’t feel hot
Aurora occurs here

16. Aurora Borealis: Particles from the Suns solar winds interact with the magnetic field of the Earth to form the Aurora.