1. Atmosphere Carrie Vollmer Topic 2161

2. Troposphere 10 miles (5-16 km) where we live Contains:  Nitrogen – 78%  Oxygen – 21%  Almost all water vapor Decreasing temperature/pressure  Air expands under less pressure  As air expands it cools Thinnest at the poles - 5 Km

3. Why is the sky blue? Oxygen redirects sunlight High frequency blue light is scattered first Brightest between 10 a.m. and 2 p.m. 45 degrees above the horizon Oxygen redirects sunlight High frequency blue light is scattered first Brightest between 10 a.m. and 2 p.m. 45 degrees above the horizon

4. Why is the sky red at dusk? Light goes through more atmosphere Most short wavelength scattered out Only long wavelength reaches our eyes Red has the longest wavelength

5. Stratosphere 30 miles (50 Km) above the Earth Ozone in the upper regions  Protects from UV light  CFC’s (Chlorofluorocarbons) reduce the amount of atmosphere

6. What causes Ozone depletion? CFC’s (Chlorofluorocarbons) Hazardous Air Pollutants (HAPs) Vehicles Industries Lead Nitrogen Oxide (NO x ) Sulfur Dioxide (SO 2 )

7. Mesosphere Temperature decreases with height 80 Km above the Earth

8. Thermosphere 120 Km above the Earth Absorbs ultraviolet and X-ray radiation from the sun Above 80 km is called the ionosphere  Knocks off electrons, producing ions  Reflects and absorbs radio waves

9. Exosphere 500 km above the Earth Made of oxygen and hydrogen atoms  Rarely collide  Some escape into space

10. Magnetosphere Earth acts like a huge magnet Two bands of electrons (-) and protons (+)  3,000 km and 16,000 km above  Van Allen radiation belts