Adelfa Champaca Sampaguita

1. THE EARTH’S ATMOSPHERE

2. The atmosphere is the envelope of gases that surround our planet It is a very thin layer compared to the radius of the Earth We refer to this layer informally as “air”

3. The majority of the energy that drives the atmosphere is from the Sun. The atmosphere receives most of this energy from the surface.

4. Atmospheric Composition Dry air (neglecting water vapor) is composed of the following gases: Nitrogen (N2) = 78% Oxygen (O2) = 21% Argon (Ar) = 1% Trace Gases Dust, bacteria, and other particulates

5. Atmospheric Composition Trace Gases Gases that are only found by examining a million or billion air molecules Examples include: Carbon Dioxide (CO2) = 340 ppmv Neon (Ne) = 18 ppmv Helium (He) = 5 ppmv Methane (CH4) = 2 ppmv Hydrogen (H2) = 0.5 ppmv

6. Atmospheric Molecules Note that the Oxygen, Nitrogen, and Hydrogen that we breathe are not single atoms of that gas, but instead are two atoms of that gas bonded together in what is called a diatomic molecule. Ozone is an example of a triatomic molecule with three oxygen atoms.

7. Atmospheric Composition Water vapor (H2O) is a variable gas. You will see it depends on temperature and the availability of liquid water. A volume of air can have between 0% and 4% water vapor, and this varies both in time and space.

8. THE EARLY ATMOSPHERE

9. Hydrogen and Helium as starting materials Presence of methane and ammonia

10. Water vapor, carbon dioxide, nitrogen

11. OUTGASSING Formation of oceans and other bodies of water Formation of early limestone and rocks Depletion of carbon dioxide and water  abundance of nitrogen gas

12. Abundance of oxygen ? Hydrogen H2O Oxygen

13. LAYERS of the ATMOSPHERE

15. TROPOSPHERE Innermost layer Contains most of the air molecules necessary for life Starts at the surface of the earth – 17 km vertically Weather changes

17. Lowest Part Higher temperature Higher Part Temperature decreases Air pressure is lower

18. Above 11 km Temperature stops decreasing (tropopause) Remains constant with height

20. STRATOSPHERE About 20 km above Earth’s surface Extends from about 17 to 48 km Temperature gradually increases Ranges from -60C to -50 C

21. Calm air Almost same composition as the troposphere but with greater water vapor and ozone “global sunscreen”

22. Presence of OZONE molecules Absorbs UV radiation Formation of OZONE O2 + UV  2O O + O2  O3 O3 + UV  3O2

23. OZONE LAYER Region between 20 km and 30 km

25. The UPPER ATMOSPHERE MESOSPHERE Above 50 km Air is very thin Very few oxygen molecules Average temperature is -90 C

26. THERMOSPHERE Outermost layer Very few molecules of air present High temperature ( 2000 C) auroras Ionosphere

28. EXOSPHERE Very thin layer which merges into the outer space.

30. Global Processes GREENHOUSE EFFECT OZONE SHIELD

31. SHORT QUIZ  Why is the OZONE LAYER very important to human life ? Greenhouse effect and ozone shield are natural processes essential to life that takes place in the atmosphere. What happens to these when we add chemicals to the atmosphere? Be specific.

32. The Air We Breathe N2 CO2 Water vapor

34. Useful application in industry

35. Inert filler gas for light bulbs

37. AIR POLLUTION

38. WHAT is AIR POLLUTION?

39. Stationary and Area Source STATIONARY SOURCE emission source that does not move large emitters who release relatively consistent qualities and quantities of pollutants.

40. Stationary and Area Source AREA SOURCE smaller stationary sources located together whose individual emissions may be low but whose collective emissions can be significant

41. Mobile Sources capable of moving under its own power; imply on-road transportation non-road or off-road category (gas-powered lawn tools and mowers, farm and construction equipment, recreational vehicles, boats, planes, and trains)

42. Agricultural Sources raise animals and grow crops, can generate emissions of gases, particulate matter, and chemical compounds.

43. Agricultural Sources For example, animals confined to a barn or area (rather than field grazing), produce large amounts of manure. Manure emits various gases, particularly ammonia into the air.

44. Agricultural Sources In crop production, the misapplication of fertilizers, herbicides, and pesticides can potentially result in aerial drift of these materials.

45. Natural Sources not caused by people or their activities erupting volcano emits particulate matter and gases forest and prairie fires can emit large quantities of pollutants

46. Natural Sources not caused by people or their activities plants and trees emit hydrocarbons; and dust storms can create large amounts of particulate matter.

47. Natural Sources wild animals in their natural habitat are also considered natural sources of pollution given that there is a certain amount of natural pollution, it is very important to control the "excess" pollution caused by man’s activities.

48. Major Pollutants PRIMARY Enters the air as the direct result of a specific activity SECONDARY Formed by the further reaction of a primary air pollutant

49. Sulfur dioxide 4 FeS2 + 11O2 2Fe2O3 + 8 SO2 oxygen iron oxide sulfur dioxide pyrite or iron pyrite forms as coal and petroleum products burn an irritating gas with a harsh acrid odor Primary or secondary?

50. Sulfur trioxide 2 SO2 + O2 2 SO3 sulfur dioxide oxygen sulfur trioxide Highly irritating gas Choking, irritating sensations

51. Sulfur trioxide 2 SO3 + H2O  H2SO4 sulfur trioxide water sulfuric acid Dissolves in atmospheric water droplets to produce acid rain Primary or secondary? SOx

52. Nitrogen oxides (NOx) N2 + O2 2 NO nitrogen oxygen nitric oxide Nitrogen comes from the air rather than from impurities in fuels High temperature of lightning and combustion chambers of the internal combustion engine Primary or secondary?

53. Nitrogen dioxide 2 NO + O2 2 NO2 nitric oxide oxygen nitrogen dioxide Red-brown toxic gas Irritation to the eyes and the respiratory system Inflammation of the lungs, fatal in a few days Produce HNO3, a component of acid rain Primary or secondary?

54. OUTDOOR Air Pollution

55. Fuel Combustion

56. Carbon monoxide Odorless, tasteless, and invisible Drowsiness, headache, dizziness, and nausea Has greater affinity to hemoglobin Can lead to asphyxiation or even death

57. Soot Soft black allotrope of carbon Contains PAHs

58. Carbon dioxide Primary product of combustion A greenhouse gas

59. Lead (Pb) Burning of leaded gasoline Neurotoxin Other sources of lead ?

60. Airborne Pathogens Disease-causing agents SARS

61. Particulate Matter Very small solid or liquid droplets Soot, pollen, smoke particulates, and dust PM-10 Lead, iron, copper, nickel particulates

62. Photochemical Smog sunlight NO2 NO + O nitrogen dioxide nitric oxide oxygen atom O + O2 O3 oxygen atom oxygen molecule ozone

63. Photochemical Smog a still, sunny day temperature inversion (pollutants accumulate in the lower inversion layer)

65. Organic compounds VOC and VOS Volatile hydrocarbon components of consumer products (paint thinners, roof tar, petroleum distillates) Evaporating solvents and propellants (nail polish, deodorants, after-shave lotions, hair sprays, insecticides) Ethyl acetate and more exotic additives that you exhale (chewing gum and breath fresheners)

66. Acid Deposition

67. Acid Rain

68. Acid Rain

69. Ozone Depletion OZONE a form of oxygen, contains three oxygen atoms unstable and will readily combine with other atoms found in the stratosphere, where it blocks the sun's ultraviolet (UV) waves and prevents them from reaching the earth's surface also found in the troposphere, where it can damage livingtissue and human-produced objects. It is generated both from certain types of pollution and natural sources

70. ozone absorbs the potentially harmful ultraviolet (UV) radiation from the sun

71. Ozone www.epa.gov/ozone/science/sc_fact.html Source: World Meteorological Organization, Scientific Assessment of Ozone Depletion: 1998, WMO Global Ozone Research and Monitoring Project - Report No. 44, Geneva, 1998

72. Ozone

73. Ozone Depletion Chain Initiation Chain Propagation

74. ozone The “ozone hole” forms over Antarctica during the Southern Hemisphere spring. In 2001, the ozone hole extended over about 26 million square kilometers, larger than the area of the continental United States! Southern Hemisphere September 17, 2001

75. INDOOR Air Pollution

76. HW. Notebook What is indoor pollution? What are the sources of indoor pollution? List at least 5 chemical found in your household that can be a source of indoor pollution.

77. INDOOR Air Pollution

78. Environmental Tobacco Smoke ETS Combination of mainstream smoke and sidestream smoke Contains about 4000 chemical compounds Ammonia, hydrogen cyanide, toluene Nicotine

79. Common Household chemicals Insects spray Toilet cleaners Moth repellants Dog sprays Shampoos Air freshener Colognes Perfumes

80. HW. Notebook