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Chapter 17: Atmospheric Science and Air Pollution.

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Presentation on theme: "Chapter 17: Atmospheric Science and Air Pollution."— Presentation transcript:

1 Chapter 17: Atmospheric Science and Air Pollution

2 Atmosphere surrounds earth consists of N 2, O 2, Ar and others today's altering molecules consist of CH 4, O 3, CO 2 made up of layers ozone layer

3 Other Atmospheric Properties atmospheric pressure – force per unit of area that air exerts on the surface of Earth – declines with altitude atmospheric humidity – ratio of water vapor contained in a given volume of air in relation to it's maximum amount possible – the more humidity the hotter it seems

4 Seasons determined by the positioning in relation to the sun atmosphere absorbs 70% of the energy the shorter the distance, the more intense the sun rays solar radiation intensity is lower at the poles and higher at the equator tilting of the planet causes the seasons to occur

5 Air Circulation known as convective circulation caused by differences in humidity and temperature warm air rises as it is less dense cold air descends becoming denser

6 Weather & Climate Weather specifies atmospheric conditions over short periods of time and related to relatively small areas Climate describes patterns of atmospheric conditions across large regions and over long periods of time

7 Weather depends on the fronts – cold thunderstorms – warm light rain affected by the pressure systems – high fair to dry weather – low results in clouds and precipitation

8 Thermal Inversion cooler air appears under warmer air prevents normal convective circulation to occur pollution is trapped under the inversion layer creating health problems like asthma – killer smog in London – asthma in San Joaquin valley

9 Global Climate Patterns Hadley cells: between equator and 30º – heavy rain at the equator – arid at 30º

10 Global Climate Patterns Ferrer cells and polar cells lift air creating rain at ~60º

11 Wind Patterns caused by the interaction of Hadley and Ferrer cells and Earth's rotation Coriolis effect: winds are curved

12 Outdoor Air Pollution air pollutants – natural sources – human made sources

13 Natural Pollutants we have no control, occur naturally – volcano eruptions Mt. Pinatubo – produces particles – circle the globe and remain in suspension for months – acid rain – affect temperature

14 Natural Pollutants dust storms Texas dust storm 1930's Dallas dust storm 2007

15 Natural Pollutants Fires – soot and gases – fuel buildup – slash-and-burn in tropics – El Niño 2000 Gulf Coast T TX LA

16 Human Created Outdoor Pollution primary pollutants – emitted directly to the troposphere – can be harmful to the environment – can form chemicals harmful to the environment secondary pollutants – react with constituents of the atmosphere

17 Clean Air Act 1970 – set stricter standards for air quality – imposed limits to emissions – funds for pollution control research 1990 – strengthen air quality standards – emission trading program for sulphur dioxide – other emission trading programs developed

18 EPA Standards carbon monoxide (CO) sulphur dioxide (SO 2 ) nitrogen dioxide (NO 2 ) tropospheric ozone (O 3 ) particulate matter lead (Pb)

19 Carbon Monoxide colorless odorless incomplete combustion in the U.S. 78% of it comes from vehicles small concentrations can be lethal to most living organisms

20 Sulphur Dioxide colorless pungent odor power plants of coal once in the atmosphere SO 2 reacts forming SO 3 and later forming H 2 SO 4 H 2 SO 4 forms acid rain

21 Nitrogen Oxides contributes to smog NO 2 is foul smelling, redish brown gas NO x cause acid rain product of combustion engines vehicles produce 50% of the U.S. NO X electricity production and industry the rest

22 Ozone product of sunlight + heat + NO X + carbon chemicals health risk because of its instability O 2 + Oxygen ion oxygen ion can cause tissue damage tissue damage can cause respiratory problems

23 Particulate Matter particles suspended in air – primary pollutants dust and soot – secondary pollutants sulphates and nitrates can damage respiratory tissues wind-blown result of human activities

24 Lead particulate matter enters food chain can cause nervous system malfunction present in gasoline to improve performance – industrialized nations phased out leaded gasoline – industrial metal smelting is the problem now

25 VOCs volatile organic compounds hydrocarbons – methane forms part of natural gas – propane used as portable fuel – butane used in portable lighters – octane component of gasoline

26 Pollutants in the U.S trillion tons EPA data

27 Pollution Decreased since 1970 emissions declined 53% since 1970 – cleaner burning vehicles – catalytic converter – clean coal technology – baghouse filters – electrostatic precipitators – scrubbers – phase-out of lead in gasoline

28 Toxic Pollutants 188 toxic pollutants identified by the Clean Air Act in 1990 effects on people – cancer – reproductive defects – neurological problems – developmental problems – affect the immune system – respiratory diseases

29 Policy: Bush Administration elimination of new source review of 1977 – new pollution targets – retrofitting aging plants with new technologies – industry protested: too costly Bush Administration exempted older plants allowed installing only "the best available" technology IF they ever upgraded the plant Clear Skies (stopped by the Senate in 2005) – from command-and-control to a market-based cap-and- trade

30 Smog fogs polluted by smoke= smog – industrial smog – photochemical smog

31 Industrial smog gray-air smog coal or oil burning CO, CO 2, soot mercury and sulfur in the carbon sample sulfur reacts forming SO 2 – sulphuric acid – ammonium sulphate Problems today: China, India, Eastern Europe London 1952

32 Photochemical smog requires light brown-air smog – ozone – NO x – VOCs irritates eyes, nose, throat car inspections reduction of vehicles driven per day – allow certain cars to drive certain days of the week – promote mass transit Houston 2000

33 Problems at Rural Areas airborne pesticides industrial pollutants from cities, factories and power plants migrate methane from cattle (18%) feedlots – CH 4, dust, NH 4, SO x can cause respiratory problems

34 Industrialization is worsen air quality caused by factories and power plants emissions are released with little effort to control pollution China & India have 58% of premature deaths worldwide (WHO) Asian brown cloud – reduces sunlight – decreases productivity China

35 Synthetic Chemicals CFCs (chlorofluorocarbons) affects the ozone layer creating the ozone hole in Antarctica increases UV radiation leads to more skin cancer ecological effects still unknown hole in the arctic Arctic hole

36 Montreal Protocol of 1987 addressed ozone depletion 180 nations agreed to cut CFCs production in half production and use has dropped by 95% alternative chemicals CFCs take very long to brake down

37 Acid Deposition – forms of precipitation known as acid rain rain, snow, sleet and hail – fog – dry particles originates with the NO x and SO x pollutants react with water, O 2, oxidants produce compounds of low pH (acids) these are suspended in the troposphere before falling as rain can cause political bickering

38 Acid Rain alters soil composition – leaches chemicals from the soil – harming plants and soil organisms – also mobilizes toxic chemicals – converts them to soluble forms – affects agriculture – affect lakes and rivers causing high mortality in fishes and amphibians

39 Acid Rain erosion of buildings corrodes cars erosion of statues and obelisks has not been reduced as expected in 1990 more reduction of sulphur oxides and nitrogen oxides need to occur

40 Indoor Air Pollution higher concentration of pollutants indoor than outdoor workplaces, schools, homes volatile chemicals in the air – insecticides – cleaning fluids – plastics – chemically treated wood

41 Other Sources wood burning – chimneys – cooking tobacco smoking radon

42 Indoor VOC Pollution perfumes paints plastics oils/candles cleaning fluids adhesives (glues) pesticides and insecticides ink (fax, photocopiers, printers) color films

43 Living Organisms also Pollute dust mites animal dander mold bacteria THE END

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