2. ATM OCN 100 Summer 2002 1 ATM OCN 100 – Summer 2002 LECTURE 3 PHYSICAL & CHEMICAL COMPOSITION of EARTH’S ATMOSPHERE (con’t.) u A. Practical Questions u B. Present Earth’s Atmosphere u C. Origin & Evolution of Earth’s Atmosphere u D. Atmospheres of other Planets u E. Variation of charged particles with height

3. MADISON’S CURRENT WEATHER Madison Weather at 1000 AM CDT THR JUN 20 2002 Updated twice an hour at :05 and :25 Sky/Weather: CLOUDY Temperature: 78 F (25 C) Dew Point: 66 F (18 C) Relative Humidity: 66% Wind: SW9G17 MPH Barometer: 30.21R (1023.0 mb)

4. ATM OCN 100 Summer 2002 3 QUIZ!!! u Which way does the wind circulate around a high pressure center? u And around a Low? u Why sunny skies? u Answers….

5. ATM OCN 100 Summer 2002 4 Current Surface Weather Map with Isobars (“iso” = equal & “bar” = weight), Fronts and Radar Isobars

6. ATM OCN 100 Summer 2002 5 Current Surface Winds with Streamlines & Isotachs (“iso” = equal & “tach” = speed) Isobars H H L

7. ATM OCN 100 Summer 2002 6 Current Temperatures ( ° F) & Isotherms (“iso” = equal +”therm” = temperature)

8. ATM OCN 100 Summer 2002 7 Tomorrow AM Forecast Map

9. ATM OCN 100 Summer 2002 8 Did You know that – Tomorrow is summer solstice (8:24 AM CDT) See Fig. 2.10 Moran & Morgan (1997)

10. ATM OCN 100 Summer 2002 9 Announcements u Sign-up –Class list –Official registration (NLT Fri. 21 June) –Course Syllabus F NOTE Change Wed. to Fri. 21 Dec. on back u Homework 1: Due next Thurs. 27 June

11. ATM OCN 100 Summer 2002 10 ATM OCN 100 – Summer 2002 LECTURE 2A PHYSICAL & CHEMICAL COMPOSITION of EARTH’S ATMOSPHERE (con’t.) u A. Practical Questions u B. Present Earth’s Atmosphere

12. ATM OCN 100 Summer 2002 11 ATM OCN 100 – Summer 2002 LECTURE 3 PHYSICAL & CHEMICAL COMPOSITION of EARTH’S ATMOSPHERE (con’t.) u A. Practical Questions u B. Present Earth’s Atmosphere – Composition – Vertical variation in composition

13. ATM OCN 100 Summer 2002 12 QUIZ!!! u Which way does the wind circulate around a high pressure center? u And around a Low? u Answers….

14. ATM OCN 100 Summer 2002 13 ERIN CURRENT IR

15. ATM OCN 100 Summer 2002 14 Current Temperatures ( ° F) & Isotherms (“iso” = equal +”therm” = temperature)

16. ATM OCN 100 Summer 2002 15 Current Surface Weather Map with Isobars (“iso” = equal & “bar” = weight), Fronts and Radar Isobars

17. ATM OCN 100 Summer 2002 16 ATM OCN 100 – Summer 2002 LECTURE 2A PHYSICAL & CHEMICAL COMPOSITION of EARTH’S ATMOSPHERE u A. PRACTICAL QUESTIONS – What makes Planet Earth special? – How has the atmosphere evolved?

18. ATM OCN 100 Summer 2002 17 Earth-Rise (Apollo Mission)

19. ATM OCN 100 Summer 2002 18 SUNRISE FROM SPACE From STS-52 (JSC-NASA)

20. ATM OCN 100 Summer 2002 19 B. PRESENT EARTH’S ATMOSPHERE u Background –Early Greek Thought F The 4 Elements: Earth, Air, Water, Fire. –“Modern” Chemistry (since 18 th century) F Element F Compound F Mixture u Chemical Composition –Air is a mixture –With the following gases:

21. ATM OCN 100 Summer 2002 20 B. PRESENT EARTH’S ATMOSPHERE u Background –Early Greek Thought F The 4 Elements: Earth, Air, Water, Fire. –“Modern” Chemistry (since 18 th century) F Element F Compound F Mixture u Chemical Composition –Air is a mixture

22. ATM OCN 100 Summer 2002 21 Atmospheric Gases isolated by 18 th Century Chemists u Nitrogen (N 2 ) –Importance in Food Chain (Nitrogen Fixation) u Oxygen (O 2 ) –Critical Importance for Life (Respiration) u Argon (Ar) –Unknown Importance u Carbon Dioxide (CO 2 ) –Critical Importance for Life (Photosynthesis) (also Asphyxiation)

23. ATM OCN 100 Summer 2002 22 See Table 1.2 Moran & Morgan (1997)

24. ATM OCN 100 Summer 2002 23 B. PRESENT EARTH’S ATMOSPHERE (con’t.) u Vertical Variations of Atmospheric Composition –Criterion F Chemical –Divisions F HOMOSPHERE F HETEROSPHERE – Where...

25. ATM OCN 100 Summer 2002 24 VERTICAL COMPOSITION VARIATIONS (con’t.) u HOMOSPHERE – “Homo” = same (percentage composition) ; – Turbulent mixing; – Below 80 km altitude. u HETEROSPHERE – “Hetero” = different (composition); – Fractional diffusion (by molecular weight); – Above 80 km altitude.

26. ATM OCN 100 Summer 2002 25 CONSTITUENTS OF AIR in the HOMOSPHERE (Below 80 km) u Principal Permanent Gases of “Dry Air” u Principal Variable gases u Anthropogenic Gases u Aerosols – Liquids or solids suspended in Atmosphere u Clouds – Liquid droplets or ice crystals in Atmosphere

27. ATM OCN 100 Summer 2002 26 CONSTITUENTS OF AIR in the HOMOSPHERE (Below 80 km) u Principal Permanent Gases of “Dry Air” u Principal Variable gases u Anthropogenic Gases u Aerosols – Liquids or solids suspended in Atmosphere u Clouds – Liquid droplets or ice crystals in Atmosphere

28. ATM OCN 100 Summer 2002 27 PRINCIPAL FIXED GASES in the “Dry” Homosphere u Nitrogen (N 2 ) –Importance in Food Chain (Nitrogen Fixation) u Oxygen (O 2 ) –Critical Importance for Life (Respiration) u Argon (Ar) –Unknown Importance u Carbon Dioxide (CO 2 ) –Critical Importance for Life (Photosynthesis) (also Asphyxiation)

29. ATM OCN 100 Summer 2002 28 See Table 1.2 Moran & Morgan (1997)

30. ATM OCN 100 Summer 2002 29 PRINCIPAL VARIABLE GASES in the Homosphere u Water Vapor (H 2 O) < 4% by volume u Carbon Dioxide (CO 2 ) 360 ppm = 0.036% u Methane (CH 4 ) < 1700 ppb = 0.00017% u Ozone (O 3 ) < 8 ppm = 0.0008%

31. ATM OCN 100 Summer 2002 30 Recent Atmospheric CO 2 Concentrations See Fig. 2.25 Moran & Morgan (1997)

32. ATM OCN 100 Summer 2002 31 Mauna Loa Observatory, HI

33. ATM OCN 100 Summer 2002 32

34. 33 Ozone u A paradox – Good and Bad u Natural production & destruction where…

35. ATM OCN 100 Summer 2002 34 Ozone Formation Figure 2.18 Moran & Morgan (1997)

36. ATM OCN 100 Summer 2002 35 Ozone Destruction (Natural) Figure 2.18 Moran & Morgan (1997)

37. ATM OCN 100 Summer 2002 36 Ozone u A paradox u Natural production & destruction u Location in Atmosphere

38. ATM OCN 100 Summer 2002 37 8 ppmv = 0.0008%

39. ATM OCN 100 Summer 2002 38 ANTHROPOGENIC SUBSTANCES u Chlorofluorocarbons (CFCs) u Volatile Organic Compounds – (Hydrocarbons) u Oxides of nitrogen (NO, NO 2 ) u Oxides of carbon (CO, CO 2 ) u Sulfur compounds ( H 2 S, SO 2, SO 3 ) u Suspended particulates

40. ATM OCN 100 Summer 2002 39 AEROSOLS u What they are – Suspended solid particles or liquid droplets in atmosphere. u Sources – Natural – Human activity F Where….

41. ATM OCN 100 Summer 2002 40 Aerosols from Wildfires 11 May 2000 ( NOAA-15)

42. ATM OCN 100 Summer 2002 41 Aerosols from Colorado Wildfires 10 June 2002 ( SSEC - MODIS)

43. ATM OCN 100 Summer 2002 42 Aerosols from Volcanoes Mt. St. Helens, WA May 1980

44. ATM OCN 100 Summer 2002 43 Volcanic Plume from Mt. Etna 23 July 2001 ( NOAA-14)

45. ATM OCN 100 Summer 2002 44 Aerosols-Dust from Mongolia 10 Apr 2001

46. ATM OCN 100 Summer 2002 45 Aerosols from Blowing Dust

47. ATM OCN 100 Summer 2002 46 Aerosols from Sea Spray (Calif. Coast)

48. ATM OCN 100 Summer 2002 47 Aerosols from Natural Vegetation in Great Smoky Mtn. Natl Park, NC-TN

49. ATM OCN 100 Summer 2002 48 Aerosols from Urban Pollution Madison (from Space Science & Eng. Center)

50. ATM OCN 100 Summer 2002 49 PRINCIPAL VARIABLE GASES in the Heterosphere (above 80 km) u Diatomic nitrogen (N 2 ) 85 to 200 km u Monatomic oxygen (O) 200 to 1100 km u Helium (He) 1100 to 3500 km u Atomic hydrogen (H) 3500 to 11,000 km

51. ATM OCN 100 Summer 2002 50 C. ORIGIN & EVOLUTION of Earth’s Atmosphere u General History of the Atmosphere – 4.5 billion yr ago - Solar System formed Early Atmosphere – 3 billion yr ago - Primitive life forms – 2 billion yr ago - First free oxygen in air – 1 billion yr ago - Increased oxygen – 400 million yr ago - First terrestrial plants – 200 million yr ago - High oxygen levels

52. ATM OCN 100 Summer 2002 51 C. ORIGIN & EVOLUTION of Earth’s Atmosphere u How did our current atmosphere evolve? u General History of the Atmosphere – 4.5 billion yr ago - Solar System formed – And then…

53. ATM OCN 100 Summer 2002 52 C. ORIGIN & EVOLUTION of Earth’s Atmosphere

54. ATM OCN 100 Summer 2002 53Evolution

55. 54 Nitrogen cycle

56. ATM OCN 100 Summer 2002 55 Nitrogen cycle

57. ATM OCN 100 Summer 2002 56

58. 57 ATMOSPHERIC ORIGIN & EVOLUTION (con’t) u Rationale – Planet Earth is special because of large amounts of O 2 ; – Atmosphere & Life Co-evolved. u Human Intervention – Humans could possibly affect concentrations of some gases, with following…

59. ATM OCN 100 Summer 2002 58 Enhanced “Greenhouse Effect” u Background

60. ATM OCN 100 Summer 2002 59 Enhanced “Greenhouse Effect” u Increases in “Greenhouse Gases” –CO 2 and CH 4 u Why more CO 2 ? –Burning of fossil fuels –Deforestation –Changes in Sea Surface Temperature

61. ATM OCN 100 Summer 2002 60 Global CO 2 Emissions Marland, et.al. 2001 Carbon Dioxide Information Analysis Center

62. ATM OCN 100 Summer 2002 61

63. 62 CO 2 measurements at Mauna Loa, HI See Fig. 2.25 Moran & Morgan (1997)

64. ATM OCN 100 Summer 2002 63 CO 2 measurements at South Pole

65. ATM OCN 100 Summer 2002 64 Enhanced “Greenhouse Effect” (con’t.) u Increases in “Greenhouse Gases” –CO 2 and CH 4 u Why more CO 2 ? –Burning of fossil fuels –Deforestation –Changes in Sea Surface Temperature u Potential Implications –Ice cap melting & coastal flooding –Changes in agricultural areas –Increases in diseases and pests

66. ATM OCN 100 Summer 2002 65 See Fig. 19.9 Moran & Morgan (1997)

67. ATM OCN 100 Summer 2002 66 “Ozone Hole” u Background u Destruction of Stratospheric Ozone –From CFCs

68. ATM OCN 100 Summer 2002 67 Destruction of ozone by CFCs. See Fig. 2.19, Moran & Morgan (1997)

69. ATM OCN 100 Summer 2002 68 CFC & other Solvent Concentrations in Atmosphere (Source: NOAA/CMDL)

70. ATM OCN 100 Summer 2002 69 Evolution of the “Ozone Hole” NASA TOMS Project

71. ATM OCN 100 Summer 2002 70 Recent “Ozone Hole” Status NASA TOMS Project

72. ATM OCN 100 Summer 2002 71 “Ozone Hole” (con’t.) u Background u Destruction of Stratospheric Ozone –From CFCs u Potential Implications –Increased skin cancer –Increased cataracts –Unknown changes to food chain

73. ATM OCN 100 Summer 2002 72 D. ATMOSPHERES of OTHER PLANETS u General Composition Considerations: – Planetary Size (influences planetary gravity) – Closeness to Sun (influences temperature) u Atmospheric Composition of Planets – Inner Planets – Outer Planets

74. ATM OCN 100 Summer 2002 73 PLANETARY COMPOSITION [Source: Densities from “Astronomical Almanac”]

75. ATM OCN 100 Summer 2002 74 E. VARIATION OF CHARGED PARTICLES WITH HEIGHT u Composition – Ions: Charged Particles u Location – Ionosphere – Magnetosphere u Implications – Radio Communications – Aurora Borealis (Australis) u The Reason - Active Sun

76. ATM OCN 100 Summer 2002 75 Ionosphere Figure 1.11 Moran & Morgan (1997)

77. ATM OCN 100 Summer 2002 76 Magnetosphere See Fig. 1.13 Moran & Morgan (1997) Northern Lights Planetarium

78. ATM OCN 100 Summer 2002 77 MAGNETOSPHERE

79. 78 AURORA BOREALIS (from Univ. of Alaska)

80. ATM OCN 100 Summer 2002 79 The Northern Lights Planetarium

81. ATM OCN 100 Summer 2002 80

82. 81 Aurora from Space Shuttle

83. ATM OCN 100 Summer 2002 82 The Northern Lights Planetarium

84. ATM OCN 100 Summer 2002 83 Did You know that – Tomorrow is summer solstice (2:38 AM CDT) See Fig. 2.10 Moran & Morgan (1997)

85. ATM OCN 100 Summer 2002 84