1. History Clean Air Act EPA “Criteria Pollutants”
Ozone (O3), carbon monoxide (CO), lead (Pb), nitrogen dioxide (NO2), particulate matter (PM), sulfur dioxide (SO2)
National Ambient Air Quality Standards (NAAQS) O3 CO Pb
NO2 PM
SO2

2. Table 12-2, p.328

3. Table 12-1, p.320

4. FIGURE 12.2 (a) Estimates of emissions of the primary air pollutants in the United States on a per weight basis; (b) the primary sources for the pollutants. (Data courtesy of United States Environmental Protection Agency.)
Fig. 12-2, p.320

5. FIGURE 12.1 Strong northeasterly Santa Ana winds on October 28, 2003,blew the smoke from massive wild fires across southern California out over the Pacific Ocean.
Fig. 12-1, p.319

6. Fig. 12-3, p.321 Photochemical Smog Recipe:
sunlight + nitrogen dioxide + volatile hydrocarbons = ozone + PM + other pollutants
Rocky Mountains are visible in relatively clean air
FIGURE 12.3 (a) Denver, Colorado, on a clear day, and (b)on a day when particulate matter and other pollutants greatly reduce visibility.
PM + other pollutants reduce visibility in smoggy air
Fig. 12-3, p.321

7. Typical diurnal cycle in ozone concentration (max
Typical diurnal cycle in ozone concentration (max. occurs in early afternoon).
Maximum occurs after injection of pollutants from morning rush hour and after sufficient time has elapsed for the photochemical reactions to proceed
Tucson air quality data from:
Air Info Now
FIGURE 12.6 Average hourly concentrations of ozone measured at six major cities over a two-year period.
Fig. 12-6, p.324

8. FIGURE 12.9 Emission estimates of six pollutants in the United States from1940–1995. (Data courtesy of United States Environmental Protection Agency.)
Fig. 12-9, p.328

9. FIGURE The number of unhealthful days(by county) across the United States for any one of the five pollutants(CO, SO2, NO2, O3, and particulate matter) during1990. (Data courtesy of United States Environmental Protection Agency.)
Portuguese explorer, Juan Rodriguez Cabrillo, named this natural harbor Bahia de los Fumos or "Bay of Smokes" in We call it San Pedro harbor.
Fig , p.329

10. FIGURE The smoke from the shorter stack is trapped within the inversion, while the smoke from the taller stack, above the inversion, rises, mixes, and disperses downwind.
Fig , p.331

11. As the vertical temperature profile changes during the course of a day(a through c), the pattern of smoke emitted from the stack changes as well.
p.332

12. An example of an elevated inversion layer – characteristic of the Pacific west coast
FIGURE The inversion layer prevents pollutants from escaping into the air above it. If the inversion lowers, the mixing depth decreases and the pollutants are concentrated within a smaller volume.
Fig , p.333

13. FIGURE 12. 13 A thick layer of polluted air is trapped in the valley
FIGURE A thick layer of polluted air is trapped in the valley. The top of the polluted air marks the base of a subsidence inversion and the top of the mixing layer.
Fig , p.333

14. FIGURE 12.14 The leading edge of cool, marine air carries pollutants into Riverside, California.
Fig , p.333

15. FIGURE 12.15 At night, cold air and pollutants drain downhill and settle in low-lying valleys.
Fig , p.334

16. Surface weather map that shows a stagnant anticyclone over the eastern United States on October 26, The heavy arrow represents the position of the jet stream.
p.335

17. Table 12-3, p.336

18. FIGURE On a clear, relatively calm night, a weak country breeze carries pollutants from the outskirts into the city, where they concentrate and rise due to the warmth of the city’s urban heat island. This effect may produce a pollution (or dust) dome from the suburbs to the center of town.
Fig , p.337

19. FIGURE The pH scale ranges from 0 to 14, with a value of 7 considered neutral. Values greater than 7 are alkaline and below 7 are acidic. The scale is logarithmic, which means that rain with pH 3 is 10 times more acidic than rain with pH 4 and 100 times more acidic than rain with pH 5.
U.S. record: acid fog in Corona del Mar, CA, with pH = 1.7
Fig , p.338

20. FIGURE 12.18Annual average value of pH in precipitation weighted by the amount of precipitation in the United States and Canada for1980.
Mainly from coal burning power plants in Ohio River valley that generate primary pollutants SO2 and NO2 that are converted to sulfuric and nitric acids, respectively
Fig , p.338

21. FIGURE 12.19 The effects of acid fog in the Great Smoky Mountains of Tennessee.
Fig , p.339

22. Fig. 12-7, p.325 CF3Cl + UV light = Cl Cl + O3 = O2
90% of ozone column
FIGURE The average distribution of ozone above the earth’s surface in the middle latitudes.
Slow (decades)
10% of ozone column
CF3Cl
Fig. 12-7, p.325

23. Ozone distribution over the Southern Hemisphere on September 11, 2003, as measured by the Total Ozone Mapping Spectrometer(TOMS). Notice that the area of lowest ozone concentration or ozone hole (purple shades) is larger than Antarctica and represents the second largest ozone hole ever observed.
p.330a

24. Color image of total ozone amounts over the Northern Hemisphere for March 24, Notice that minimum ozone values (purple shades) appear over a region near the North Pole. The color scale on the bottom of the image shows total ozone values in Dobson units(DU). A Dobson unit is the physical thickness of the ozone layer if it were brought to the earth’s surface(500 DU equals 5 mm).
p.330b

25. FIGURE 12.8 An ozone molecule absorbing ultraviolet radiation can become molecular oxygen (O2) and atomic oxygen (O).
Fig. 12-8, p.326