2. Earth’s Unique Atmosphere 1. Magnetic Field: a layer of electrical charges that protects Earth from solar winds and cosmic rays Caused by: the liquid metal in Earth’s outer core

3. Earth’s Unique Atmosphere 2. Ozone Layer: A layer of O 3 molecules that reflects UV radiation

4. Ozone  Good Ozone: Found in the stratosphere Keeps out harmful UV radiation  Bad Ozone: Found in the troposphere Causes pollution and harms lung tissue

5. Ozone Depletion  Humans are releasing CFC gases into the atmosphere that destroy ozone molecules

6. CFC’s  Chlorofluorocarbons: gases that break up ozone molecules  New Regulations: Montreal Protocol (1987): Now products are made with little or no CFC gases to protect our ozone layer

7. Earth’s Unique Atmosphere 3. Greenhouse Effect: Certain gases trap heat inside Earth’s atmosphere and reflect heat back to Earth’s surface

8. Greenhouse Gases  Any gas that traps heat inside Earth’s atmosphere  Carbon dioxide: CO ₂  Methane: CH ₄  Water Vapor: H₂O  Nitrous oxide: N₂O  Sulfur Dioxide: SO₂

9. Exosphere  300-6000 miles above Earth’s surface  Extremely hot 200-2000 ºF  Mostly Hydrogen and Helium molecules  Beginning of outer Space

10. Thermosphere  50-300 miles above Earth’s surface  Temperature increases with altitude -80 to 200° F  Space shuttle, space station and satellites orbit here  Aurora: A natural light display caused by energetic particles interacting with Earth’s magnetic field

11. Mesosphere  30-50 miles above Earth’s surface  Temperature decreases with altitude Coldest layer: -130 to 0 °F  Meteors burn up in this layer  Noctilucent clouds: high clouds made of ice crystals

12. Stratosphere  6-30 miles above Earth’s surface  Temperature increases with altitude -100 to 30 °F  Good ozone layer Reflects harmful UV radiation  Military air space  Jet stream: A current of rapidly moving air  Radiosonde: Weather balloon

13. Troposphere  0-6 miles above Earth’s surface  Temperature decreases with altitude: -100 to 60 ºF  Highest air pressure = Contains most air molecules  Bad ozone: causes air pollution  Weather and cloud formation  Commercial airplanes fly here  Highest mountain: Mt. Everest 5.5 miles

14. Atmospheric Temperature Graph

15. 90 miles Thermosphere 50 miles Mesosphere 30 miles Stratosphere 6 miles Troposphere -120 ⁰F -60 ⁰F 0 ⁰F 60 ⁰F 120 ⁰F