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NATS 101 Lecture 31 Air Pollution Meteorology. AMS Glossary of Meteorology air pollution—The presence of substances in the atmosphere, particularly those.

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Presentation on theme: "NATS 101 Lecture 31 Air Pollution Meteorology. AMS Glossary of Meteorology air pollution—The presence of substances in the atmosphere, particularly those."— Presentation transcript:

1 NATS 101 Lecture 31 Air Pollution Meteorology

2 AMS Glossary of Meteorology air pollution—The presence of substances in the atmosphere, particularly those that do not occur naturally. atmosphere These substances are generally contaminants that substantially alter or degrade the quality of the atmosphere. The term is often used to identify undesirable substances produced by human activity, that is, anthropogenic air pollution. anthropogenic Air pollution usually designates the collection of substances that adversely affects human health, animals, and plants; deteriorates structures; interferes with commerce; or interferes with the enjoyment of life.

3 Major Air Pollution Episodes of Historic Significance Some of the worst events in the last two centuries occurred in London –Key ingredients - calm winds, fog, smoke particles from coal burning –1873 - 700 deaths –1911- 1150 deaths –1952 - 4000 deaths Last event led to the Parliament passing a Clean Air Act in 1956 Other notable events over western Europe 1930 - Meuse Valley –Key ingredients – calm winds, strong inversion close to ground, fog, smoke from factories –Pollution trapped in lowest 70-80 m of a narrow valley –600 very ill, 60 deaths

4 Major Air Pollution Episodes of Historic Significance Some of the worst events in the last two centuries occurred in London –Key ingredients: calm winds, fog, smoke particles from coal burning –1873 - 700 deaths –1911- 1150 deaths –1952 - 4000 deaths Last event led to the Parliament passing a Clean Air Act in 1956

5 Major Air Pollution Episodes of Historic Significance Other notable events over western Europe 1930 - Meuse Valley, Belgium –Key ingredients: calm winds, strong inversion close to ground, fog, smoke from factories –Pollution trapped in lowest 70-80 m of a narrow valley –600 very ill, 60 deaths

6 http://www.atmos.washington.edu/2005Q4/212/Kaufman_health.pdf

7 Major U.S. Air Pollution Episodes of Historic Significance U.S. air quality degraded with the beginning of the industrial revolution Coal burning in Central and Midwest U.S. –1948 Donora, PA in the Monongahela River Valley –20 died, 1000’s ill in 5 days Prompted Air Pollution Control Act of 1955 –Ignored automobiles 1960s - NYC had several severe smog episodes 1950s onward – LA had many smog alerts from increase in industry and motor vehicle use Led to passage of the Clean Air Act of 1970 (updated 1977 and 1990) –Empowered Feds to set emission standards that each state had to meet

8 Major U.S. Air Pollution Episodes of Historic Significance U.S. air quality degraded shortly after the beginning of the industrial revolution Coal burning in Central and Midwest U.S. –1948 Donora, PA in the Monongahela River Valley –20 deaths, 1000’s took ill in 5 days Prompted Air Pollution Control Act of 1955 –Ignored automobiles

9 Major U.S. Air Pollution Episodes of Historic Significance 1960s - NYC had several severe smog episodes 1950s onward – LA had many smog alerts from an increase in industry and motor vehicle use Led to passage of the Clean Air Act of 1970 (updated 1977 and 1990) –Empowered Federal Government to set emission standards that each state had to meet

10 U.S. Air Pollution Examples 1963 photo of a severe smog episode in New York City. (Photo: AP/Wide World Photo, EPA Journal Jan/Feb 1990.) Smog in San Gabriel Valley, 1972. (Photo: EPA.)

11 Air Pollution in Grand Canyon Even remote areas are affected by pollution Canyon on a clear day Canyon on a hazy day http://apollo.lsc.vsc.edu/classes/met130/notes/ http://apollo.lsc.vsc.edu/classes/met130/notes/ Nice link to Lyndon Valley State College that has useful material for a NATS-type course

12 Primary Pollutants Injected directly into atmosphere Carbon Monoxide (CO) –odorless, colorless, poisonous gas –byproduct of burning fossil fuels –body acts as if CO is O2 in blood, can result in death Nitrogen Oxides (NOx, NO) –NO - nitric oxide –emitted directly by autos, industry

13 Primary Pollutants Sulfur Oxides (SOx) –SO2 - sulfur dioxide –produced largely through coal burning –responsible for acid rain problem Volatile Organic Compounds (VOCs) –highly reactive organic compounds –released through incomplete combustion and industrial sources Particulate Matter (dust, ash, smoke, salt) –10 um particles (PM10) stay lodged in your lungs –2.5 um particles (PM2.5) can enter blood stream

14 Secondary Pollutants Form in atmosphere from chemical-photochemical reactions that involve primary pollutants Sulfuric Acid H2SO4 –major cause of acid rain Nitrogen Dioxide NO2 –brownish hue L.A. Sky Colors Dec 2000 Mark Z. Jacobson

15 Secondary Pollutants Ozone O3 –colorless gas –has an acrid, sweet smell –oxidizing agent Primary and secondary pollutants are found in the two types of smog: –London-type smog –LA-type photochemical smog SMOG = SMOKE + FOG

16 Human Response to One Hour Pollutant Exposure (Turco, p194) Pollutant Concentration Part per million by mass Symptom CO 10-30 ppmmTime distortion (typical urban level) 100 ppmm Throbbing headache (freeway background, 100 ppmm) 300 ppmm Vomiting, collapse (tobacco smoke, 400 ppmm) 600 ppmmDeath CO sticks to hemoglobin, forming carboxyhemoglobin (COHb), which reduces the capacity of hemoglobin to carry O2 to cells

17 Physiology of Exposure to CO http://apollo.lsc.vsc.edu/classes/met130/notes/ COHb level is 5%-15% for cig puffers!

18 Human Response to One Hour Pollutant Exposure (Turco, p194) Pollutant Concentration Parts per million by mass Symptom NO2 0.06-0.1 ppmm Respiratory impact (long term exposure promotes disease) 1.5-5.0 ppmmBreathing difficulty 25-100 ppmmAcute asthma 150 ppmmDeath (may be delayed)

19 Human Response to One Hour Pollutant Exposure (Turco, p194) Pollutant Concentration Parts per million by mass Symptom O3 0.02 ppmmOdor threshold (sweet) 0.1 ppmm Nose and throat irritation in sensitive people 0.3 ppmmGeneral nose and throat irritation 1.0 ppmm Airway resistance, headaches (long term lead to premature aging of lung tissue)

20 Human Response to One Hour Pollutant Exposure (Turco, p194) Pollutant Concentration Parts per million by mass Symptom SO2 0.3 ppmmTaste threshold (acidic) 0.5 ppmmOdor threshold (acrid) 1.5 ppmm Bronchiolar constriction Respiratory infection

21

22 Table 12-2, p.328

23 SMOG and Haze over China January 10, 2003 http://www.nasa.gov/centers/goddard/news/topstory/2003/0110chinahaze.html

24 Beijing Air Pollution http://www.terradaily.com/news/pollution-05zs.html Record Pollution Levels AQI > 300 - Hazardous 11-5-2005 AFP Photo Where’s Beijing? 11-4-2005 NASA MODIS Visible

25 Fig. 12-4, p.322 Pollution Knows No Boundaries April 2001 China Dust Transport Across Pacific

26 U.S. Pollutant Trends 1940-1995 Most pollutants decreased after the 1970 Clean Air Act Lead Particulates SO 2 VOC’s CO NO 2 is Leveling Off Fig. 12-9, p.328

27 Fig. 12-10, p.329 AQI > 150 for CO, SO2, NO2, O3 and PM

28 http://www.arb.ca.gov/research/health/fs/pm-03fs.pdf

29 Table 12-1, p.320 90% total pollutants 10% total pollutants

30 Fig. 12-2a, p.320 Percentage of Primary Pollutants

31 Fig. 12-2b, p.320 Percentage of Primary Sources

32 Air Pollution Weather Strong low-level inversion Subsidence inversion that diurnal heating does not break or weaken significantly Weak surface winds Persistent surface anticyclone Sunny weather for photochemical smog Hot weather to accelerate O3 production

33 Fig. 12-12, p.333 Stable Layer Unstable Layer

34 Fig. 12-13, p.333 Top of Mixing Layer

35 Fig. 12-15, p.334 Valleys Trap Pollutants L.A. is in a basin surrounded by mountains that trap pollutants and usually has onshore flow that creates frequent inversions. Pollutants can only escape through narrow canyons

36 Fig. 12-14, p.333 Leading Edge of Sea Breeze and “Smog Front” over Inland SoCal

37 Ozone Production VOCs create Reactive Organic Gases (ROGs). ROGs react to form radicals. Alkylperoxy radical (RO2*) oxidizes NO to form NO2 faster than NO reacts with O3. Thus O3 is not destroyed to produce NO2. Each time a NO2 molecule is formed, it quickly results in the production of O3. http://apollo.lsc.vsc.edu/classes/met130/notes/

38 Air Pollution Dispersion Air pollution dispersion is often studied with simple models, termed Box Models. How is a box defined for the LA basin? Box Model Boundaries for the LA Basin Ventilation factor is a simple way of relating concentrations of pollutants to parameters that modulate the dispersion of pollutants in a local environments. An increase in either the mixing height or the wind speed increases the effective volume in which pollutants are allowed to mix. The larger the volume, the lower the pollution concentration. How does a box model work?

39 Ventilation Factor (VF) Mixing Height Length = Wind Speed  Time VF = Mixing Height  Wind Speed Volume ~ Length  Height

40 Acid Rain and Deposition Sulfur dioxide (SO2) and oxides of nitrogen (NOx) within clouds (including fog) form acidic particles when they react with water: SO2 + H2O  H2SO4 (sulfuric acid) NOx + H2O  HNO3 (nitric acid) Acid Rain is worse downstream of the point sources of pollution Acid Rain affects Trees, Lakes, Structures Acid Deposition is a world-wide problem

41 Fig. 12-17, p.338 pH is logarithmic scale. An one unit change denotes a factor of 10 difference.

42 pH = 5.6 for pristine rain

43 Fig. 12-19, p.339 Acidified Forest in Czechoslovakia http://www.atmos.washington.edu/2005Q4/212/AcidDepositionSlides.pdf

44 Impact on Aquatic Organisms http://www.epa.gov/airmarkets/acidrain/effects/surfacewater.html#fish

45 Sandstone Figure in Germany 19081968 Herr Schmidt-Thomsen http://www.atmos.washington.edu/2005Q4/212/AcidDepositionSlides.pdf

46 Summary Air Pollutants – Long History –Primary: CO, NOx, SOx, VOC, PM –Secondary: H2SO4, NO2, O3 Global Problem - Knows No Boundaries! –Serious Health Consequences US Air Improving - Clean Air Act But It is Degrading in Emerging Economies Air Pollution Weather and Air Dispersion Acid Rain

47 Next Assignments Next Class – Quiz #6 Next Lecture Topic – Ozone Depletion Reading – Ahrens pg 324-327, 330 Problems – 12.10, 12.11


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