1. Composition Earth Science / Mr. Bimber
Earth’s Atmosphere
Composition
Earth Science / Mr. Bimber

2. What’s in the air? The atmosphere is: 78% nitrogen 21% oxygen 1% argon
0.04% carbon dioxide
Varying amounts of:
water vapor
pollutants
dust

3. What are the different layers?
Outer Space
(Exosphere)
Thermosphere
Mesosphere
Stratosphere
Troposphere
Solid earth

4. Troposphere Has most of the air Higher it’s cooler
Most clouds are here
Storms happen here
9-16 kilometers high
Bottom layer

5. Stratosphere Second lowest layer 10-50 kilometers high
Has cool, dry air
Above the clouds
Higher its warmer
Ozone layer heats it
Some planes fly here

6. Mesosphere “meso” means middle 50-90 kilometers high
Higher it’s cooler again
Top is -110 Fahrenheit

7. Thermosphere Above Mesosphere About 100 kilometers
Friction with solar wind causes “northern lights”
Higher it’s warmer again
“thermo” means hot
Top is 1,800 Fahrenheit

8. Exosphere
Top layer
Above 100 kilometers
Fades out to nothing

9. How was our atmosphere formed?
Comets and meteors
Earth melted inside
Volcanoes erupted
Gases
Steam
Rivers, lakes, oceans
Plants
Released oxygen
First animals
Life possible on land

10. Is our atmosphere changing?
Big meteors
Fires, tidal wave
Dust
Block sunlight
Cools the planet
Extinction
Dinosaurs
Us?
Industry (humans)
CFCs
Ozone hole
Acid rain
Smog
Carbon dioxide
climate change

11. Why are there layers? Temperature changes: Outer Space Cooling Heating
Solid Earth

12. How does heat move? Conduction Convection Radiation
Atoms bump each other.
Convection
Hot atoms expand and flow upward
Radiation
Waves travel through space

13. Conduction Heat = energy of atoms vibrating.
When fast moving atoms speed up their slow neighbors, that’s conduction.
Mostly solids, liquids
Metals conduct heat faster than wood.

14. Convection Hot gases and liquids expand and float up.
Cold gases and liquids shrink, and sink.
Heat travel by flowing atoms is called convection.
“Heat rises” - that’s why flames point upward.

15. Radiation Heat can travel in waves, like light.
This is called radiation.
Radiation from the sun is called insolation (short for INcoming SOLar radiATION )
Earth radiates some heat out to space.

16. Heat flows through the atmosphere
Temperature changes differently in each layer.
The air is heated:
At ground level
In the Ozone layer
By friction with solar wind

17. Heat in the Atmosphere
The balance and flow of heat energy in the atmosphere
Causes weather
Protects life on earth