1. Atmosphere  Catalyst  In what direction does the Earth revolve around the sun? In what direction does the Earth rotate?  Which is warmer: direct sunlight or indirect sunlight?  Why do the Northern Hemisphere and Southern Hemisphere experience different seasons at the same time? Write in complete sentences! Don’t talk during the Catalyst!

2. Objectives By the end of today, all SWBAT…  Describe the relationship between air pressure and altitude  Describe the 5 layers of the atmosphere

3. Quick Recap  What is atmosphere?  What are some gases in the atmosphere?  Where did oxygen come from?  Who uses it?

4. HW Review

5. New vocabulary  Altitude: height above the earth  Pressure: the amount of push “down”

6.  Key Point #1: As altitude increases, pressure decreases  The higher up you go, the less stuff there is above you pushing down Earth

7. Four layers of the atmosphere  Key Point #2: There are four major layers of the atmosphere:  Troposphere  Stratosphere  Mesosphere  Thermosphere

8. Why are there different layers?  The atmosphere is made up of gases  Mostly nitrogen and oxygen  Less oxygen as you go up  There are different amounts of each gas in different places— this forms layers

9.  Location: 0-9 km above earth  Features:  Most mass  Lots of oxygen  Weather, pollution and life happen in the troposphere Troposphere

10.  Location: 10-50 km above Earth  Features:  Where the ozone layer (which protects us from the Sun) is located Stratosphere

11. Mesosphere  Location: 50-80 km above Earth’s surface  Features:  Coldest layer  Shooting stars begin burning in the mesosphere

12.  Location: 80-120 km above earth  Function:  Fewest gas particles  Almost no oxygen  Where Aurora borealis (Northern lights) occurs Thermosphere

13. Compete!  Find a partner at your table  Take turn quizzing each other about the layers of the atmosphere  Don’t let your partner use their notes when answering  First person to 10 points is the winner!

14. Try these on for size  Order the layers of the atmosphere from lowest to highest.  Which layer of the Earth’s atmosphere experiences the least pressure? How do you know?  Which layer of the Earth’s atmosphere has the most oxygen? Why?  What would happen to life on Earth if we switched all the characteristics of the troposphere with all the characteristics of the thermosphere?

16. Trashketball  Teams in tables  2 minutes to solve  Team with the MOST COMPLETE correct answer shoots.  You must be able to DEFEND your answer to shoot for it  Scoring  Dunk = 1 point  Field goal = 2 points  Three-pointer = 3 points

17. Explain how altitude is related to pressure, and why As altitude increases pressure decreases, because there is less stuff in the atmosphere pushing down on you

18. Ms. Stroh doesn’t know anything about environmental science. She thinks that the mesosphere protects us from the Sun. Correct her mistake. The stratosphere protects us from the Sun, because the stratosphere contains the ozone layer, which filters out harmful solar radiation

19. Explain what would happen to life on Earth if we switched the amount of oxygen in the thermosphere with the amount of oxygen in the troposphere All life on Earth would die! There is almost no oxygen in the thermosphere. Without oxygen, all animals (including us!) would die 

20. Which layer of the atmosphere experiences the greatest amount of pressure? Explain why. Troposphere It is the lowest layer of the atmosphere, and therefore has the most stuff above it pushing down

21. Many people believe that the thermosphere is colder than the mesosphere, because it is higher up. Why are they wrong? The mesosphere is colder than the thermosphere. Temperature is determined by how much of each gas there is, not altitude.

22. Dumb ol’ Ms. Stroh loves the stratosphere, because that’s where shooting stars burn. Explain to her why she is wrong. The stratosphere is where the ozone layer is located, not where shooting stars burn. Ms. Stroh is thinking of the mesosphere.

23. If you’re looking into the sky and watching the Aurora Borealis, which layer of the atmosphere are you watching? Thermosphere The Aurora Borealis occurs in the thermosphere

24. Which layer of the atmosphere experiences the least amount of pressure? Explain why. Thermosphere It is the highest layer of the atmosphere, and therefore has the least stuff above it pushing down

25. Explain what would happen to life on Earth if we switched the temperature of the mesosphere with the temperature of the troposphere All life on Earth would die! The mesosphere is super cold. All life would all freeze to death! 

26. Closing  More altitude = more pressure  Can I get one volunteer to…  State the layers of the atmosphere in order  Identify the most important characteristic of each layer of the atmosphere

27. Exit Questions  Which layer of the Earth’s atmosphere experiences the greatest pressure?  Yesterday, you overheard Taylor saying, “The thermosphere has to be the coldest layer of the Earth’s atmosphere, because it is the closest to space.” Now you know he’s wrong. Please correct him!  Using your knowledge of what occurs in the troposphere, please explain what would happen if an evil scientist moved all of its oxygen into the mesosphere.