Earth’s Atmosphere

1. Earth’s Atmosphere

2. What newsworthy weather events have you noticed in the media?

3. Weatherbug • http://achieve.weatherbug.com/Home.aspx#target1 • http://www.wnep.com/weather/regionaldoppleriiradar/

4. Can you describe what you see in this picture? In this chapter you will learn about Earth’s atmosphere, and the gases that support life.

5. Size of the Earth • 1. Diameter = from the north pole to the south pole it’s ~ 7916 miles • 2. Circumference ~ 24,901 miles • Equator- imaginary line that divides the earth into hemisphere’s (north and south)

7. Tell the person next to you what the 3 most important features of earth • 1. land lithosphere • 2. air atmosphere • 3. water hydrosphere

8. Viking---astronomy connection

9. 5-2 Development of Earths atmosphere Past Atmosphere 4 billion yrs ago Methane Ammonia Water

10. Atmosphere at 3.8 billion yrs. old New gases Ammonia water hydrogen nitrogen Methane water Methane Carbon dioxide Methane Ammonia water

11. water Ozone= 3 oxygen atoms combined together to form a protective layer water water water Water H20 H 0 0 H 0 H 0

12. Due to the ozone • Blue-green bacteria started to become more abundant • used sunlight, carbon dioxide (co2) and water to make food, their byproduct was oxygen

13. Present Atmosphere

14. 5-3 Layers of the Atmosphere What do mountain climbs have to carry as they climb higher into the atmosphere?

15. La Rinconada, Peru

17. Layers of the atmosphere depends on temperature changes

18. Troposphere • Almost all weather occurs here • 2. Extends 11miles high • 3. Jet stream 56 mi. 31mi. 11 mi.

19. Convection currents Currents of air are produced as warm air rises and cool air replaces it.

20. Convection currents • Movement of air caused by a difference in temperature • What’s really happening • Cool dense air is sinking and warm, less dense air is rising, causing a movement of air

21. Stratosphere • Lower stratosphere temp. = extremely cold

22. Stratosphere • Jet stream winds- strong eastward wind that blows horizontally around the earth

23. Stratosphere • Ozone layer • Ozone ( a form of oxygen, O3) reacts with the uv light to warm the air • Protects earth from harmful uv radiation Warm = 64° f Cold = -76°f

24. Stratosphere • Temperatures increase as you ascend. Why? • The Ozone Layer absorbs ultraviolet rays, giving off heat. • The Jet Stream

25. Video-15 min • http://www.youtube.com/watch?v=L4CX7GL_DPo

26. Mesosphere • coldest area of the atmosphere • Shooting Stars- what are they? • Protect us from falling meteoroids

27. Meteoroids, meteors and meteorites • Meteoroid: An object in space no smaller than a speck of dust and no larger than an asteroid. Most are thought by scientists to be pieces of asteroids or comets. • Meteor: The streak of light that forms when a meteoroid burns while traveling at high speed through Earth's atmosphere (a "shooting star" or "falling star"). • Meteorite: The remnants of a meteoroid that has passed through the atmosphere and struck the Earth.

28. Thermosphere • No definite Limit • Very Hot? Why • Nitrogen and Oxygen absorb a lot of UV radiation and convert it to heat • Thin air makes seeing objects in space more easily.

29. Ionosphere • Lower layer of the thermosphere • Gas molecules are electrically charged • Radio waves bounce back • Brilliant light displays of aurora borealis occur here

30. Exosphere Thermosphere • Outer layer of thermosphere • Satellites orbit Earth here • Communicate long-distance telephone and television signals • Watch weather and weather patterns • No definite upper limit

31. Magnetosphere • Extends above Earth • Magnetic field that traps charged particles from the sun • Particles follow the lines of magnetic force and bounce back and forth from one pole to the other • Sometimes breaking through into the ionosphere to produce auroras

32. Aurora Borealis, Northern Lights