1. 17_00CO.JPG Ch. 17 Atmosphere and Air Pollution

2. Rules/Regulations http://streaming.factsonfile.com/PortalPlaylists.as px?aid=17963&xtid=35562&loid=31344

3. New York City – Congestion pricing??

4. The atmosphere’s composition Composition

5. 17_02.JPG Thermosphere Up to 500km (300 mi) High temp – would feel cold Mesosphere 50-80km (31-56mi) Low pressure, temp. drops Stratosphere 11-50 km (7-31 mi) Drier/less dense Temp. increases with altitude due to O3 (17-30kim or 10-19 mi) Troposphere Avg. thickness 11km (7 mi) Weather Temperature/density decline with altitude

7. 17_03.JPG Atmospheric Pressure= force per unit area produced by a column of air Sea Level = 1013 mb (14.7 lb/in 2 ) 29035 ft (Everest top) = 300mb

9. Atmospheric properties Relative humidity = the ratio of water vapor a given volume of air contains to the amount it could contain at a given temperature. Expressed as percent

10. Temperature = average kinetic energy in molecules Thermometer = molecular speedometer

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12. Equator – Angle of incident radiation perpendicular, greatest concentration of energy Poles – Angle of incident radiation obtuse, less concentrated ***The troposphere is warmed primarily by convection

13. 17_05.JPG Seasons

14. Weather: local physical properties of the troposphere over short time periods: temp, pressure, cloud cover, wind, humidity Climate: patter of atmospheric conditions found across large geographic regions over long periods of time

16. 17_06.JPG Convective Circulation

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20. Air Pollutants removed by: –Precipitation –mixing

21. 17_08a.jpg Mixing removes pollutants

22. 17_08b.jpg Pollutants trapped

23. 17_09.JPG Large scale convective cells determine global patterns of humidity and aridity

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26. 17_09b.jpg Coriolis Effect – apparent deflection of air from straight path as globe moves beneath

27. 17_10a.jpg Outdoor Air Pollution (Ambient) Natural Sources: Dust Storms Carry fungal and bacterial spores

28. 17_10b.jpg Volcanoes: Particulates including ash, aerosols of SO 2 can cool atmosphere

29. 17_10c.JPG Fires: Particulates and gases

30. Types of outdoor air pollution Point Sources = specific spots where large quantities of pollutants are discharged (power plants and factories) Nonpoint Sources = more diffuse, consisting of many small sources (automobiles) Primary Pollutants = directly harmful,and can react to form other harmful substances Secondary Pollutants = form when primary pollutants interact with components of the atmosphere Anthropogenic Sources

31. Primary Pollutants Stationary Mobile Sources Natural Most hydrocarbons Most suspended particles SO 2 NO NO 2 CO CO 2 Secondary Pollutants SO 3 HNO 3 H 2 SO 4 H2O2H2O2H2O2H2O2 O3O3O3O3 PANs Most NO 3 – SO 4 2– salts

32. Successful legislation Clean Air Act of 1970 –standards for air quality –limits on emissions –funds for pollution-control research –Allows citizens to sue parties violating the standards The Clean Air Act of 1990 –Strengthens standards for auto emissions, toxic air pollutants, acidic deposition, stratospheric ozone depletion –Introduced emissions trading for SO 2

33. 6 Criteria Pollutants

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37. What is the good news????

38. Air pollution has decreased since 1970

39. 17_14.JPG Remove up to 90% particulates and SO 2

40. Reasons for the decline in U.S. pollution Cleaner-burning vehicles and catalytic converters decrease carbon monoxide Permit-trading programs and clean coal technologies reduce SO 2 emissions Scrubbers = technologies that chemically convert or physically remove pollutants before they leave the smokestacks Phaseout of leaded gasoline Improved technologies and federal policies

41. 17.16 Industrial smogPhotochemical smog

42. 17_16a.jpg Photochemical Smog

43. Photochemical (brown air) smog Produced by a series of reactions –Hot, sunny cities surrounded by mountains –Light-driven reactions of primary pollutants and normal atmospheric compounds –Morning traffic exhaust releases pollutants –Irritant – eyes, throat, nose –decreased due to emissions testing Photochemical Smog

44. 1. 2NO+ O 2  2NO 2 2. NO 2 + UV  NO + O 3. O 2 + O  O 3 Typical Daily Patterns Air Quality Guide for Ozone

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47. 17_SBS01-02.JPG Stratospheric Ozone

48. The hole in the ozone Ozone hole = ozone levels over Antarctica had declined by 40-60% –Depletion also in the Arctic and globally –Causes skin cancer, harms crops and decreases ocean productivity

49. The Montreal Protocol addressed ozone depletion Montreal Protocol = 180 nations agreed to cut CFC production in half –Follow-up agreements deepened cuts –ozone-depleting chemicals has decreased 95% –The ozone layer is beginning to recover –Success story included industry adaptive management strategy –Model for international cooperation

50. Sources of acid deposition Originates from burning fossil fuels that release sulfur dioxide and nitrogen oxides –These compounds react with water to form sulfuric and nitric acids Acid Deposition

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53. Acid deposition has not been greatly reduced Scrubbers have helped SO 2 emissions are lower (cap and trade) But, NO x emissions are higher Acid Deposition not Greatly Reduced

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56. 17_23.JPG Indoor Air Quality

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