Presentation on theme: "Presentation Slides for Air Pollution and Global Warming: History, Science, and Solutions Chapter 3: Structure and Composition of the Present- Day Atmosphere."— Presentation transcript:
Presentation Slides for Air Pollution and Global Warming: History, Science, and Solutions Chapter 3: Structure and Composition of the Present- Day Atmosphere By Mark Z. Jacobson Cambridge University Press (2012) Last update: January 20, 2012 The photographs shown here either appear in the textbook or were obtained from the internet and are provided to facilitate their display during course instruction. Permissions for publication of photographs must be requested from individual copyright holders. The source of each photograph is given below the figure and/or in the back of the textbook.
Toricelli's 1643 Experiment With Mercury Barometer Edgar Fahs Smith Collection, U. Penn. Library Le Puy de D ô me, France www.wired.cz
Toricelli's Experiment With Mercury Barometer Example 3.1. How much mercury balances 1000 hPa of pressure?
Processes Affecting Temperature Conduction Transfer of energy from molecule to molecule Convection Transfer of energy by vertical mass movement of a fluid Advection Transfer of energy by horizontal movement of a fluid Radiation Energy transferred in the form of electromagnetic waves Temperature Proportional to kinetic energy of an air molecule traveling at its average speed
Atmosphere Up to Thermosphere www.ucar.edu lasp.colorado.edu Aurora in Thermosphere
Jan/July Temperature vs. Altitude/Latitude Altitude (km) Figure 3.5 Altitude (km) Latitude (degrees)
Equation of State Boyle’s Law(3.3) p~1/V Charles’ Law(3.4) V ~T Avogadro’s Law(3.5) V~n Ideal gas law (3.6) (simplified equation of state) p= nR*T/V = Nk B T Number concentration N = nA/V Boltzmann’s constant k B = R*/A Lifting of a parcel of air
Charles Law and Hot Air Balloon Montgolfier Hot Air Balloon June 4, 1783 www.aps.org Charles’s Hydrogen Balloon Aug. 27, 1783 www.aps.org “The country people who saw it fall were frightened and attacked it with stones and knives so that it was much mangled” – Ben Franklin
Equation of State p=Nk B T k B = 1.3807 x 10 -19 cm 3 hPa K -1 Example 3.4: Earth’s surface p = 1013 hPa T = 288 K ----> N = 2.55 x 10 19 molecules cm -3 48 km altitude p = 1 hPa T = 270 K ----> N = 2.68 x 10 16 molecules cm -3
Dalton’s Law of Partial Pressure Edgar Fahs Smith Collection, U. Penn. Library Total air pressure equals sum of partial pressures of individual gases in the air.
Equation of State for Dry Air Total atmospheric pressure (3.11) p a = p d +p v Equation of state for dry air (3.12) p d = N d k B T
Volume Mixing Ratio q =N q /N d = p q /p d (molecules of gas/molecule of dry air) (3.14) 1% = 0.01 = 10 4 ppmv 1 ppmv = 0.000001 = 0.0001% = 1000 ppbv = 10 6 pptv Example 3.6: Ozone q = 0.10 ppmv T = 288 Kp d = 1013 hPa -- N d = p d /k B T = 2.55 x 10 19 molec. cm -3 -- N q = q N d = 2.55 x 10 12 molec. cm -3
Composition of the Air Well-Mixed Gases Table 3.2 Volume mixing ratio Gas (percent)(ppmv) Nitrogen (N 2 )78.08780,800 Oxygen (O 2 )20.95209,500 Argon (Ar)0.939,300 Neon (Ne)0.001515 Helium (He)0.00055 Krypton (Kr)0.00011 Xenon (Xe) 0.0000050.05
Pollutants for Different Problems Table 3.4 Indoor air pollution Gases: NO 2, CO, HCHO, SO 2, organic gases, radon Particles: Black carbon, organic matter, sulfate, nitrate, ammonium, allergens, asbestos, fungal spores, pollen, tobacco smoke Outdoor urban air pollution Gases: O 3, NO, NO 2, CO, ethene, toluene, xylene, PAN Particles: Black carbon, organic matter, sulfate, nitrate, ammonium, soil dust, sea spray, tire particles, lead Acid deposition Gases: SO 2, H 2 SO 4, NO 2, HNO 3, HCl, CO 2 Particles: Sulfate, nitrate, chloride
Pollutants for Different Problems Table 3.4 Stratospheric ozone reduction Gases: O 3, NO, HNO 3, HCl, ClONO 2, chlorofluorocarbons Particles: chloride, sulfate, nitrate Global climate change Gases: H 2 O, CO 2, CH 4, N 2 O, O 3, chlorofluorocarbons Particles: black carbon, organic matter, sulfate, nitrate, ammonium, soil dust, sea spray
Carbon Dioxide [CO 2 (g)] Colorless, odorless, greenhouse gas Sources Bacterial fermentation, respiration Plant, animal, fungus, protozoa respiration Evaporation from the oceans, chemical reaction Volcanos; biomass, biofuel, fossil-fuel burning Sinks Photosynthesis Autotrophic bacterial respiration Dissolution into oceans, lakes; transfer to ice caps, soil Chemical weathering, photolysis in upper atmosphere Health effects >15,000 ppmv affect respiration; > 30,000 ppmv --> headaches, dizziness, nausea
Carbon Storage Reservoirs Table 3.7 LocationGT-C Atmosphere Gas and particle859 Surface oceans Live organic carbon5 Dead organic carbon30 Bicarbonate ion500 Deep oceans Dead organic carbon3000 Bicarbonate ion40,000 Ocean sediments Dead organic carbon10,000,000 Land/ocean sediments Carbonate rock60,000,000 Land Live organic carbon800 Dead organic carbon2000
Carbon Dioxide Aqueous Chemistry Dissolution/Dissociation(3.15,3.16) Formation of calcium carbonate(3.17)
Chemical Weathering (3.18) Breakdown and reformation of rocks and minerals at the atomic and molecular level by chemical reaction (3.19)
Instantaneous Data-Constrained Lifetime and Time-Dependent Anthropogenic Mixing Ratio of CO 2 at a Given Emission Rate Time-rate-of-change of mixing ratio Instantaneous data-constrained lifetime (changes with time) Time-dependent anthropogenic and total mixing ratio for a constant emission rate and lifetime
Ozone [O 3 (g)] Smell > 20 ppbv; clear at low and faint purple at high mixing ratio Source Atmospheric chemical reaction Sinks Atmospheric chemical reaction and photolysis Dissolution into oceans, lakes; transfer to ice caps, soil Mixing ratios 20-40 ppbv clean air; 40-500 ppbv pollution; 10 ppmv strat. Health effects >150 ppbv --> headache >250 ppbv --> chest pain, sore throat, cough, short breath Affects vegetation, rubber, textile, dyes, fibers
Ozone Teachertech.rice.edu Schoenbein Color Scale Increasing Ozone www.nine-patch.com
Nitrogen Dioxide >80 ppbv: sore throat 150-250 ppbv typical for polluted air 300-800 ppbv reduced lung capacity > 150 ppmv death
Sulfur Dioxide z.about.com Volcanoes.usgs.gov Wwwimage.cbsnews.com 1-30 ppbv: typical for polluted air >300 ppbv: taste >500 ppbv: odor >1500 ppbv: bronchial restrictions > 40,000 ppbv: death
Methane [CH 4 (g)] Greenhouse gas, long lifetime, produces tropospheric ozone Sources Methanogenic bacteria Natural gas leaks Biomass, biofuel, fossil-fuel combustion Atmospheric chemical reaction Sinks Methanotrophic bacteria Atmospheric chemical reaction Dissolution into oceans, lakes; transfer to ice caps, soil Health effects None at ambient mixing ratios
Rice Paddy in Sapa, Vietnam Juliengrondin/Dreamstime.com
Distribution of PM in Airways Cormier: www.ehponline.org All PM enter nose/mouth. PM 10 passes larynx to trachea and bronchial regions. PM 2.5 and PM 0.1 enter alveoli.
Air Pollution in Lungs http://www.sciencephoto.com/image/88071/530wm/C0023802-Lung,_post-mortem-SPL.jpg
Air Pollution in Lungs http://raps.bur.st/20010427/lung-city.jpg
Asbestos in Lungs http://www.home-air-purifier-expert.com/images/asbestos-in-lungs.jpg
Lead [Pb(s)] Gray-white solid heavy metal Sources Crustal physical weathering Leaded fuel combustion, lead-acid battery manufacturing Lead ore crushing and smelting Dust from soils contaminated with lead-based paint Solid waste disposal Sinks Deposition to oceans, ice caps, soils Inhalation Health effects Lead poisoning: mental retardation, neurological impairment Plumbism: abdominal pains, black line in gums, paralysis, blindness, deafness, coma, death
Health Effects of Lead "We can take example by the workers in lead who have complexions affected by pallor. For when, in casting, the lead receives the current of air, the fumes from it occupy the members of the body, and burning them thereon, rob the limbs of the virtues of the blood. Therefore it seems that water should not be brought in lead pipes if we desire to have it wholesome." Marcus Vitruvius Pollio, Roman engineer, first-century B. C.
Thomas Midgley (1889-1944) Edgar Fahs Smith Collection, U. Penn. Library
Thomas Midgley 1916: Joined Dayton Eng. Laboratory Companies (DELCO) 1919: DELCO main research lab for General Motors (GM) 1921: Invented leaded gasoline, which he named Ethyl Lead reduced knock, increased power to vehicles 1923: VP of Ethyl Gas. Co., a GM and Standard Oil subsidiary 1923: Midgley suffered lead poisoning, but he defended lead: "The exhaust does not contain enough lead to worry about, but no one knows what legislation might come into existence fostered by competition and fanatical health cranks.”
Thomas Midgley 1923-5: 17 workers died, 149 injured due to lead poisoning 1924: 5 of the workers became suddenly insane from poisoning 1925: Despite working on ethanol/benzene blends, iron carbonyl alternatives, Midgley countered, "...tetraethyl lead is the only material available which can bring about these (antiknock) results, which are of vital importance to the continued economic use by the general public of all automotive equipment, and unless a grave and inescapable hazard exists in the manufacture of tetraethyl lead, its abandonment cannot be justified" 1924: Forced to step down as VP due to managerial problems 1924: Returned to research on synthetic rubber in Dayton for GM 1925: U.S. Surgeon General organized committee to investigate lead Observed drivers/garage workers did not experience poisoning --> “no grounds for prohibiting the use of Ethyl gasoline.”
Leaded Gasoline 1930s: 90 percent of vehicles leaded 1936: Federal Trade Commission "...entirely safe to the health of (motorists) and to the public in general when used as a motor fuel, and is not a narcotic in its effect, a poisonous dope, or dangerous to the life or health of a customer, purchaser, user or the general public." 1959: U.S. Public Health Service "...regrettable that the investigations recommended by the Surgeon General's Committee in 1926 were not carried out by the Public Health Service." 1975: Catalytic converter invented; lead deactivates catalyst 1977: Lead regulated as criteria air pollutant in the U.S.