1. I. Structure and Characteristics of the Atmosphere

2. A. Early atmosphere 1.Created from gases released from volcanoes – outgassing. a.Mostly water vapor, nitrogen, and carbon dioxide. 2.Oxygen was not part of atmosphere until a long time later a.The presence of newly formed green algae and plants released oxygen into the atmosphere.

3. B. Composition of Atmosphere 1.Mostly made of nitrogen and oxygen a.Nitrogen = 78% b.Oxygen = 21% c.A few other gases are present in small amounts.

4. C. 4 Layers 1.Troposphere 2.Stratosphere 3.Mesosphere 4.Thermosphere

6. D. Troposphere 1.Closest layer and the layer we live in! 2.Clouds, wind, rain, and snow 3.Densest Why? 4.Temperature decreases as altitude increases 5.Temperature stops decreasing – tropopause*

8. E. Stratosphere 1.2 nd layer 2.Oxygen (O 2 )-deficient; no H20 vapor 3.Temperature increases as altitude increases 1.Why does it get hotter? 4.ozone layer –upper stratosphere 1.What does ozone protect us from? 2.What is molecular formula for ozone? 3.Temperature stops increasing at - stratopause

11. Atmospheric layers video

12. F. Mesosphere 1.3 rd layer 2.Temperature decreases as altitude increases 1.No gases that absorb the sun’s radiation. 3.Coldest layer ~ -80°C*

13. G. Thermosphere 1.Temperature increases as altitude increases 1.Oxygen and nitrogen in this layer absorb sun’s radiation 2.Hottest layer ~980°C a.Convert to Farhenheit 1)Tf = 32 + 9/5 Tc Tf = 32 + 9/5 (980) Tf = ? 1796° F 3.Outer portion= exosphere

15. H. Ionosphere 1.Electrically charged ions; solar radiation 1.What is ion? 2.Positively charged ion? 2.Upper mesosphere and lower thermosphere 3.Helpful in radio communication

17. II.Air Pressure 1.Atmospheric pressure – pressure due to weight of atmosphere 2.Sea level- 14.7 pounds per square inch. 3. The more air above you, the greater the air pressure. a. Higher air pressure in Valley, than in the mountains. 1.Mercury barometer

20. Air Pressure video

21. III. Human Influence on Atmosphere 1.Clorofluorocarbons (CFC’s) destroy ozone molecules. 1.Already a hole in ozone near south pole. 2.Ozone is getting thinner. 2.Excess carbon dioxide leads to greenhouse effect 1.Transportation vehicles responsible for ½ of pollutants in air. 3.Sun’s radiation trapped – global warming 1.What effect can global warming have on environment?

23. Ozone video

24. 1.Solar radiation 2.Some radiation is reflected by clouds 3.Pollution from cars and factories release carbon dioxide. 4.Heat is released towards atmosphere. Some escapes, some is trapped by greenhouse gases.

25. Review Video