The Earth’s Atmosphere

1. The Earth’s Atmosphere Tina R. Walters 2011

2. Atmosphere Thin layer of air that forms a protective covering around the Earth.

3. Earth’s Atmosphere Made of : 1. Gases 78% nitrogen 21% oxygen 1% other gases • Solids dust, salts, pollen • Liquids

4. Five Layers of Atmosphere Lower Levels: • Troposphere A. Closest to Earth, 0-10 Km above earth. B. 99% of water vapor is found here C. 75% of atmospheric gases D. Clouds and weather

5. Five Layers of Atmosphere Lower Levels: • Stratosphere A. 10 Km- 50 Km above the Earth B. Ozone 3 oxygen molecules bonded together. C. Protects the Earth from the Sun’s rays.

6. Five Layers of Atmosphere Upper Level 3. Mesosphere 50-85 Km above the Earth 4. Thermosphere 85-500 Km above the Earth high temperatures. ****Ionosphere ******* A. Part of the Mesosphere and the Thermosphere B. Layer of electrically charged particles and radio waves.

7. Five Layers of Atmosphere 5. Exosphere few molecules space shuttle

8. Atmospheric Pressure Greater near the Earth’s surface. • Temperature Varies within layers

9. Ozone • Within Stratosphere • 18-48 Km • Shields you from the sun’s harmful rays—Ultraviolet Radiation • CFC’s Chlorofluorocarbons Found in aerosol sprays, refrigerator & air conditioner coolants. Destroys ozone.

10. Transfer of Energy Energy can be: • Reflected back into space by clouds, particles or the Earth’s surface. • Absorbed by the atmosphere • Absorbed by land or water on the Earth’s surface.

11. Heat Energy that flows from on object with higher temperature to an object with lower temperature.

12. Three Ways Energy Flows • Radiation energy that is transferred in the form of rays or waves. Examples: sun on you or the Earth • Conduction Molecules bumping into each other. Moves from warmer objects to cooler objects. Feet on the sand.

13. Three Ways Energy Flows • Convection transfer of heat by the flow of materials. Heat thru the atmosphere. Warm air is less dense and rises. Cold air is more dense and sinks. This forms a current.

14. Water Cycle Cycling of water between the atmosphere and the hydrosphere (all the water on Earth’s surface.) Figure on page 453 • Evaporation Heat changes liquid to gas (water vapor). • Condensation water vapor changes to precipitation (water). Atmosphere cools.

16. Air Movement Wind movement of air from area of high pressure to area of lower pressure. Air from Poles – cold, more dense Air from Equator – warm, less dense

17. Air Movement • Coriolis Effect Rotation of the Earth causes air & water to appear to turn to the right (North of the Equator) and turn to the left (South of the Equator). Creates wind patterns Figure 16 pg. 456

18. Global Winds • Doldrums little or no wind or rain near the equator. • Trade Winds near 30 degrees North & South latitudes. Tropical region steady winds. • Prevailing Westerlies between 30 & 60 degrees latitude Opposite direction of Trade Winds.

19. Global Winds • Polar Easterlies– near the poles North Pole flows from the northeast to the southwest. South Pole flows from the southeast to the northwest • Jet Stream Blows across the troposphere moves faster in the winter Helps moves weather across the US. Helps planes going east.

21. Sea and Land Breezes • Sea Breeze during the day land warms faster than water. Wind blows from water to land. • Land Breeze at night land cools faster than water wind blows from land to water.