1. Earth’s Atmosphere! Earth’s Atmosphere!

2. What is an atmosphere? An atmosphere is the layer of gases that surround the planet. Ours is as thin as Earth’s crust!

3. What gases is Earth’s atmosphere made of? Surprisingly, more Nitrogen than Oxygen!

4. Nitrogen The Nitrogen is actually just as important to us as Oxygen! -There is Nitrogen in our bodies (CHON) Nitrogen -Bacteria need Nitrogen to help break down our waste into plant food!

5. Carbon Dioxide Oxygen The plants give off our Oxygen which we need to breathe... Then we exhale Carbon Dioxide that the plants need to make food!

6. We think that in the time of dinosaurs there was not as much Oxygen... Because Oxygen is technically a corrosive gas! It is what turns apples brown and makes metal rust!

7. Some of our Oxygen is Ozone, which in the upper atmosphere protects us from harmful UV rays...

8. But in our lower atmosphere, it is given off by lightning and trees and is a type of air pollution!

9. water vapor There is also particulate pollution in our atmosphere such as smoke, dust, and chemicals... And there is also trace amounts of water vapor (humidity).

10. Our atmosphere has different layers! The lowest layer is the one we live and breathe in: Troposphere This is also the layer where weather occurs! (up to 19 km. above Earth) (It is thicker at the equator and thin at the poles because of Earth’s rotation!)

11. The next layer is the Stratosphere, which goes up to 50 km. above Earth. For every 1 km. higher into the stratosphere, it gets 6.5º C colder! (this is why airplane windows feel cold) This is where airplanes fly!

12. The upper stratosphere is where our ozone layer ozone layer is! The absorbed UV rays from the sun make the upper stratosphere warmer!

13. The middle layer of our atmosphere is the Mesosphere, which has very little gas and is really cold! (-90º Celcius) This layer burns up incoming objects such as meteors (shooting stars)!

14. About 80 km. above Earth is the start of the thermosphere, which has no definite end-- it just blends into space! The thermosphere is HOT (1800º C) because it is directly hit with solar radiation (the heat of the sun)

15. The lower 3/4 of the thermosphere is called the Ionosphere (80 km. - 550 km.) The ionosphere is electrically charged and makes gases glow! (aurora borealis)

16. The upper 1/4 of the thermosphere is the Exosphere (over 550 km. above Earth) This is where all our satellites orbit!

17. Troposphere Stratosphere Mesosphere Thermosphere Ionosphere Exosphere The layers of our atmosphere! Please Remember: Exo = satellites Iono = electric Thermo = hot Meso = protecting Strato = airplanes Tropo = weather