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

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.

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.

11. 10km ozone 10-50 km 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. 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. Troposphere Stratosphere

12. Troposphere 10km Stratosphere ozone 10-50 km 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. 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.

14. “Meso” means middle; hence, this is the middle layer of our atmosphere. The temperature of this layer drops from comfortable 0 0 C. to a chilling -80 0 C ! 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 0 0 C. to a chilling -80 0 C ! Most meteors burn up in this layer. 10km ozone 10-50 km Troposphere Stratosphere Mesosphere 50-80 km

16. 10km ozone 10-50 km Troposphere Stratosphere Mesosphere 50-80 km Thermosphere 80-500 km Temperatures in this layer increase from - 80°C to a hot, 800°C. The space shuttle orbits the earth in this layer.

18. 10km ozone 10-50 km Troposphere Stratosphere Mesosphere 50-80 km Thermosphere 80-500 km The Ionosphere is located in the upper Thermosphere. Ionosphere 150- 500 km

19. 10km ozone 10-50 km Troposphere Stratosphere Mesosphere 50-80 km Thermosphere 80-500 km 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. Ionosphere 150- 500 km

20. 10km ozone 10-50 km Troposphere Stratosphere Mesosphere 50-80 km Thermosphere Ionosphere 150- 500 km 80-500 km This ionization causes a natural phenomena called the Aurora Borealis.

22. 10km ozone 10-50 km Troposphere Stratosphere Mesosphere 50-80 km Thermosphere 80-500 km Ionosphere 150- 500 km Exosphere 500- 800 km The Exosphere is the outermost layer.

23. 10km ozone 10-50 km Troposphere Stratosphere Mesosphere 50-80 km Thermosphere 80-500 km Ionosphere 150- 500 km Exosphere 500- 800 km The temperature ranges from 800° to 2000°C in the Exosphere.

24. 10km ozone 10-50 km Troposphere Stratosphere Mesosphere 50-80 km Thermosphere 80-500 km Ionosphere 150- 500 km Exosphere 500- 800 km Molecules of gas are about 2km apart in the Exosphere.

25. 10km ozone 10-50 km Troposphere Stratosphere Mesosphere 50-80 km Thermosphere 80-500 km Ionosphere 150- 500 km Exosphere 500- 800 km Satellites orbiting Earth are found in the Exosphere.

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 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. 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