1. Layers of the Atmosphere

2. Our planet is surrounded by layers of atmosphere.
These layers differ in
composition
density
temperature
pressure
The differences within these layers allow life on earth to exist.

3. The atmosphere at the surface of the earth is very different from the atmosphere just a few kilometers up.
How do you think these layers work together to maintain our current living conditions here on earth?

4. The layers of atmosphere act like a blanket to protect and insulate the earth. The layers are clearly visible from outer space.

5. Thickness
The atmosphere is a very thin (relatively) layer of gas over the surface of the Earth
Earth’s radius ~ 6400km
Atmospheric thickness ~ 100km
(If you travel 100km from McKinney you will only be in Ft Worth. If you do it vertically you’d be in space!)

6. As you move away from the earth’s surface, the temperature will initially drop.
The air pressure will continue to decrease the higher you go.

7. We will begin at the surface of the earth and work our way into the outer limits of Earth’s atmosphere.

8. Troposphere

9. The layer closest to the earth is the troposphere.
This layer is approximately 10 km thick.
All life exists within this layer.
Due to rising and falling currents of air, all weather takes place within this layer.

10. Stratosphere

11. The stratosphere reaches 50km above the earth.
Temperatures increase as you enter the stratosphere. This is due to the ozone layer present at the upper edge of the layer.
The stratosphere reaches 50km above the earth.
ozone
10-50 km
Stratosphere
Troposphere
10km

12. It also keeps too much heat from escaping into the outer atmosphere.
The ozone layer is a highly reactive form of oxygen that absorbs ultraviolet light.
This layer acts like an insulator to protect the earth from harmful rays.
It also keeps too much heat from escaping into the outer atmosphere.
ozone
10-50 km
Stratosphere
Troposphere
10km

13. Mesophere

14. Most meteors burn up in this layer.
“Meso” means middle; hence, this is the middle layer of our atmosphere.
The temperature of this layer drops from comfortable 00 C. to a chilling -800 C !
Most meteors burn up in this layer.
50-80 km
Mesosphere
ozone
10-50 km
Stratosphere
Troposphere
10km

15. Thermosphere

16. Temperatures in this layer increase from -80°C to a hot, 800°C.
The space shuttle orbits the earth in this layer.
Thermosphere km
50-80 km
Mesosphere
ozone
10-50 km
Stratosphere
Troposphere
10km

17. Ionosphere

18. The Ionosphere is located in the upper Thermosphere.km
Ionosphere
Thermosphere km
50-80 km
Mesosphere
ozone
10-50 km
Stratosphere
Troposphere
10km

19. Temperatures increase as we enter this layer
Temperatures increase as we enter this layer. The atmosphere is very thin and becomes electrically charged; hence, the name ionosphere. This layer also absorbs photons (light particles) from the sun. km
Ionosphere
Thermosphere km
50-80 km
Mesosphere
ozone
10-50 km
Stratosphere
Troposphere
10km

20. This ionization causes a natural phenomena called the Aurora Borealis.km
Ionosphere
Thermosphere km
50-80 km
Mesosphere
ozone
10-50 km
Stratosphere
Troposphere
10km

21. Exosphere

22. The Exosphere is the outermost layer.km km
Ionosphere
Thermosphere km
50-80 km
Mesosphere
ozone
10-50 km
Stratosphere
Troposphere
10km

23. The temperature ranges from 800° to 2000°C in the Exosphere.km km
Ionosphere
Thermosphere km
50-80 km
Mesosphere
ozone
10-50 km
Stratosphere
Troposphere
10km

24. Molecules of gas are about 2km apart in the Exosphere.
Ionosphere
Thermosphere km
50-80 km
Mesosphere
ozone
10-50 km
Stratosphere
Troposphere
10km

25. Satellites orbiting Earth are found in the Exosphere.km km
Ionosphere
Thermosphere km
50-80 km
Mesosphere
ozone
10-50 km
Stratosphere
Troposphere
10km

26. Composition
of the Atmosphere

27. The atmosphere is composed of a variety of gases:
Nitrogen 78%
Oxygen 20.9%
Argon 0.9%
Carbon Dioxide 0.035%
Trace amounts of Helium, Neon, Methane and Krypton

28. The composition of the atmosphere remains the same throughout, the layers just vary in density.
All of life is dependent on the delicate balance of the gases found in Earth’s atmosphere.
What do you think would happen if there was a sudden increase or decrease in a certain atmospheric gas? Is it happening now? Give examples.

29. Air Density and height

30. Pressure and Density Decrease with Height

31. Low Pressure Low Density
High Pressure High Density