1. Earth’s Atmosphere

2. Take a Walk Through the Book
What looks interesting?
What are you looking forward to learning about?
What is something that you already know about?
Find a picture that looks interesting. Read the caption and write the page # down.

3. 1.1 The Big Concept
Earth’s atmosphere is a blanket of gases that supports and protects life.

4. Little Concepts The atmosphere makes life on Earth possible.
Natural processes modify the atmosphere.

5. Remember our 4 spheres
Atmosphere
Hydrosphere
Biosphere
Geosphere

6. What is the Atmosphere? Atmosphere:
Is a whole layer of air that surrounds Earth.

7. Earth’s Atmosphere Gases keep the Earth warm.
Transport energy to different regions of the planet.
Absorb and deflect radiation from the sun.

8. Density Density The amount of mass in a given space.
Density is a key concept to our atmosphere.

9. Altitude The distance above sea level.
In 1862 two balloonists reached an altitude of 8.8Km (5.5 miles)
One passed out and one barely brought their balloon down.
They found that the air gets thinner as altitude increases.

10. Altitude and Density
The higher up you go, the less air particles there are.
Where jets fly there is 1/10th the air molecules as at sea level.

11. Where Does it End?
There is no real “end” to the atmosphere. (According to our book)
The gases just keep getting less and less dense as you move away from Earth.
At 500Km (300mi) you are considered in outer space.
99% of the atmosphere’s mass is in the lowest 20 miles of the atmosphere.

12. What is the Atmosphere Made up of?
Gas Molecules
Dust
Sea Salt
Water Molecules

13. Gases in the Atmosphere
Put these gases in order from greatest to least and give them a percentage of how much of them are in our atmosphere:
Argon
Water Vapor
Oxygen
Other Elements
Nitrogen
Carbon Dioxide

14. Which Gases? Gas Percent Nitrogen Oxygen Argon Carbon Dioxide
Other Elements
Water Vapor
78.08
20.94
0.93
0.04
0.01
0-4*

15. Natural Changes Every day you breath in about 3,000 gallons of air.
About as much as it takes to fill a school bus.
Cycle:
A process that continues over and over.

16. Three Important Cycles
Water Cycle
Nitrogen Cycle
Carbon Cycle

17. The Water Cycle The water cycle has three main phases.
Evaporation- water is heated and molecules rise up into the atmosphere.
Condensation- those same water molecules cool down and start to cling together.
Precipitation- As the water molecules cling together, they are too heavy for the air to hold and they fall back to Earth.

18. The Water Cycle

19. The Nitrogen Cycle There are three main steps.
Animals remove nitrogen from the air and transform it into waste, that is deposited back to the soil.
Plants die and decay and the nitrogen in their system returns to the earth.
The soil slowly releases nitrogen gas back into the atmosphere.

20. The Nitrogen Cycle

21. The Carbon Cycle
Animals inhale oxygen and exhale carbon dioxide and water vapor.
Plants take in carbon dioxide and release oxygen.

22. The Carbon Cycle

23. Sudden Changes in Our Atmosphere
We can have sudden, natural events that change the composition of our atmosphere.
Volcanoes- The sulfur, carbon dioxide, and ash may cloud the air for long times.

24. Sudden Changes in Our Atmosphere
Forest Fires- When trees burn, the carbon in them moves into the atmosphere.
Other Storms- Wind, water and drought can loosen soil. Wind storms add particles of dirt to the air.

25. Bibliography