dye meteorology 101

Session 1A Part 2: Air Quality and Meteorology 101: 

Session 1A Part 2: Air Quality and Meteorology 101 Timothy S. Dye Clinton P. MacDonald Dianne S. Miller Sonoma Technology, Inc.

Air Quality and Meteorology 101: 

Air Quality and Meteorology 101 Objectives of this course are to provide Insights into the history of Smog Familiarity with the major pollutants, formation processes, and emission sources Description of the role of weather in Air Quality

Course Topics: 

Course Topics History of Smog Major Types of Pollutants Emission Sources Pollutant Lifecycles and Trends Key Weather Features

History of Smog (1 of 7): 

History of Smog (1 of 7) Origin: smoke and fog = Smog Ozone, hydrocarbons, nitrogen oxides, particles, and other chemically reactive compounds. The word “smog” coined in early 1900s by Harold A.   Des Veaux to describe conditions of sooty fog in Britain. Also known as “pea soupers" and "great stinking fogs".

History of Smog (2 of 7): 

History of Smog (2 of 7) AD 61 Rome, the Philosopher Seneca wrote, "as soon as I had gotten out of the heavy air of Rome and from the stink of the smoky chimneys thereof, which, being stirred, poured forth whatever pestilential vapours and soot they had enclosed in them, I felt an alteration of my disposition.“ 1300 England, King Edward II banned coal burning in London while parliament was in session and announced that “whosoever shall be found guilty of burning coal shall suffer the loss of his head.” 1552 Juan Rodriquez Cabrillo sailed into Los Angeles Bay. Upon observing smoke from Indian fires on shore rise and spread after hitting the inversion, he named it “The Bay of Smokes”. 1661    Britain, scientists John Evelyn and John Graunt found that polluted air from industry could affect vegetation and people. They suggested that industries be located in the countryside to minimize effects on health. 1750s Under stable conditions, London’s urban plume of smoke was observed at distances of 100 km

History of Smog (3 of 7): 

History of Smog (3 of 7) 1943: First recognized episodes of smog occurred in Los Angeles. Visibility was only three blocks and people suffered from itchy eyes, respiratory discomfort, nausea, and vomiting. The phenomenon was termed a "gas attack" and blamed on a nearby butadiene plant.

History of Smog (4 of 7): 

History of Smog (4 of 7) 1948 Donora, Pennsylvania, air pollution episode killed 20 people, and half the town's 12,000 residents became ill due to uncontrolled emissions from industrial facilities and stagnant weather. Source: When Smoke Ran Like Water, Devra Davis, Perseus Books

History of Smog (5 of 7): 

History of Smog (5 of 7) "Night at Noon." London's Piccadilly Circus at midday, during another deadly smog episode, this time in the winter of 1955. Source: When Smoke Ran Like Water, Devra Davis, Perseus Books Central London during the killer smog, December 1952. At this point, visibility is less than 30 feet. During the height of the smog, people could not see their own hands or feet, and buses had to be led by policemen walking with flares. Source: When Smoke Ran Like Water, Devra Davis, Perseus Books London, four days in December Mix of dense fog and sooty black coal smoke Killed thousands of Londoners December 4 smoke (PM) was 490 µg/m3 December 7 and 8 4460 µg/m3

History of Smog (6 of 7): 

History of Smog (6 of 7) On Thanksgiving Day, New York City found itself in a sea of smog caused by traffic, industry and power plants, and apartment buildings heating with coal. Weather played a role in trapping pollution beneath a temperature inversion. A smog emergency was declared for the tri-state area. Motorists were urged to stay home. Incinerators were shut down. Health officials later attributed more than 150 deaths to the pollution.

History of Smog (7 of 7): 

History of Smog (7 of 7) 1960 Air Pollution Potential – forecasting began 1963 National Air Pollution Control Agency – Started as a research body; not very effective The Air Quality Act of 1967 Designation of air quality regions Regional approach to pollution control A turning point Attitudinal change in U.S. society National Environmental Policy Act (January 1) Formation of Environmental Protection Agency (July 9) Earth Day (April 22) Clean Air Act of 1970 National Air Quality Standards Statutory deadlines for compliance

Major Types of Pollutants: 

Major Types of Pollutants What is in our air? Mixture of invisible gases, particles, and water Mostly nitrogen (78%) and oxygen (21%) Other Argon Water vapor Carbon dioxide Ozone Particulate matter and many more

Major Types of Pollutants: 

Major Types of Pollutants Categories of pollutants Primary – emitted directly from source Secondary – formed in atmosphere from reaction of primary pollutants Precursors – primary pollutants (gases) that form secondary pollutants Pollutants originate from Combustion of fossil fuels and organic matter Evaporation of petroleum products or compounds used in commercial products, services, and manufacturing Natural production of smoke from fires, dust from strong winds, and emissions from the biosphere and geosphere

Pollutants – Combustion: 

Pollutants – Combustion Complete combustion Fuel  water and carbon dioxide (CO2) Incomplete combustion Fuel  water, CO2, pollutants Pollutants are both gases and particles

Pollutants – Evaporation: 

Pollutants – Evaporation Thousands of chemical compounds Liquids evaporating or gases being released Some harmful by themselves, some react to produce other pollutants Many items you can smell are evaporative pollutants: Gasoline – benzene (sweet odor, toxic, carcinogenic) House cleaners: Pinesol – pinenes (ozone-forming) Bleach – chlorine (toxic, greenhouse gas) Plants – isoprene (ozone-forming) Trees – pinenes, limonene (ozone- and particulate matter forming) Paint – volatile organic compounds (ozone- and particulate matter forming) “New car smell” – complex mixture of VOCs including toluene, acetone, xylenes (toxics, ozone-forming) Aerosol hairspray, deodorant – butane is used as a propellant (ozone-forming) Rubber cement, nail polish – toluene (toxic, ozone-forming) Pressed wood products – formaldehyde (toxic, carcinogenic, ozone-forming) Baking bread, fermenting wine and beer – VOCs and ethanol (ozone-forming)

Pollutants – Natural Production: 

Pollutants – Natural Production Fires = combustion – Produce gases and particles Winds “pick up” dust, dirt, sand – Create particles of various sizes Biosphere – Emits gases from trees, plants, soil, ocean, animals, microbes Volcanoes and oil seeps – Produce particles and gases

Pollutants – Criteria: 

Pollutants – Criteria Response to 1970 Clean Air Act Established the National Ambient Air Quality Standards (NAAQS) for six pollutants: Nitrogen dioxide (NO2) Ozone (O3) Sulfur dioxide (SO2) Particulate matter (PM10) Particulate matter (PM2.5)* Lead (Pb) Carbon monoxide (CO) Source: U.S. EPA National Air Pollutant Emission Trends, 1900-1998 People Living in Counties with Air Quality Concentrations above the NAAQS in 2002 * established after 1970

Units of Measure: 

Units of Measure Pollution reported in several ways Concentration Amount of a material in large amount of air Parts per million (ppm) 1 in 1,000,000 Parts per billion (ppb) 1 in 1,000,000,000 Mass Weight of impurity in a volume of air Microgram per cubic meter (µg/m3) Air Quality Index Health-related physical units removed Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy

Pollutants – Ozone (1 of 3): 

Pollutants – Ozone (1 of 3) A colorless gas Composed of three oxygen atoms Oxygen molecule (O2) – needed to breathe to sustain life Ozone (O3) – extra oxygen atom makes ozone very reactive Secondary pollutant that forms from precursor gases Nitric oxide – combustion product Volatile organic compounds – evaporative and combustion products

Pollutants – Ozone (2 of 3): 

Pollutants – Ozone (2 of 3) Ozone Formation UV Key factors: Sunlight (ultraviolet) needed Amount of VOC and NO is critical Higher temperatures speed up chemical reactions

Pollutants – Ozone (3 of 3): 

Pollutants – Ozone (3 of 3) Clean-air background levels are 35-40 ppb* (sometimes lower) U.S. concentrations range from 0 to 250+ ppb* Ozone health concerns A severe irritant (reactive). Inflames and irritates the respiratory tract, particularly during physical activity. Breathing ozone can worsen asthma attacks. Symptoms include breathing difficulty, coughing, and throat irritation. Medical studies have shown that ozone damages lung tissue; complete recovery may take several days after exposure. * One-hour average

Pollutants – Ozone Experiment (1 of 4): 

Pollutants – Ozone Experiment (1 of 4) Ozone Experiment Create ozone in a bottle Materials Oxygen Flask Electrical charge Grounding wire Aluminum foil Rubber band Fruit Results Ozone is a clear gas Rubber band oxidation Gas-to-particle conversion

Pollutants – Ozone Experiment (2 of 4): 

Pollutants – Ozone Experiment (2 of 4) Fill flask with oxygen (O2) Apply electricity to break down oxygen molecules (O2) into atomic oxygen (O), which then combines with existing oxygen molecules to form ozone (O3) Making ozone in a bottle…

Pollutants – Ozone Experiment (3 of 4): 

Pollutants – Ozone Experiment (3 of 4) Flask filled with ozone – approximately 1000+ ppb! Insert rubber band into ozone-laden flask Rubber band cracks due to oxidation by ozone within five minutes Ozone reacting in a bottle….

Pollutants – Ozone Experiment (4 of 4): 

Pollutants – Ozone Experiment (4 of 4) Gas (Ozone, VOC) converting to particles… An orange serves as the volatile organic compound (terpenes) Ozone gas in the bottle with no particles Inserting a scored orange peel adds VOCs that react with ozone to form particles

Pollutants – Particulate Matter (1 of 7): 

Pollutants – Particulate Matter (1 of 7) Ultra-fine fly-ash or carbon soot * 24-hour average A complex mixture of solid and liquid particles Composed of many different compounds Both a primary and secondary pollutant Sizes vary tremendously Forms in many ways Clean-air levels are < 5 µg/m3 * Background concentrations can be higher due to dust and smoke U.S. concentrations range from 0 to 200+ µg/m3 * Health concerns Can aggravate heart diseases Associated with cardiac arrhythmias and heart attacks Can aggravate lung diseases such as asthma and bronchitis Can also increase susceptibility to respiratory infections

Pollutants – Particulate Matter (2 of 7): 

Pollutants – Particulate Matter (2 of 7) Particles come in different shapes and sizes: Particle sizes: Ultrafine particles (<0.1 μm) Fine particles (0.1 to 2.5 μm) Coarse particles (2.5 to 10 μm) PM10 Carbon chain agglomerates Crustal material

Pollutants – Particulate Matter (3a of 7): 

Pollutants – Particulate Matter (3a of 7) A unused (left) and dirty (right) PM filter

Pollutants – Particulate Matter (3b of 7): 

Pollutants – Particulate Matter (3b of 7) 2X

Pollutants – Particulate Matter (3c of 7): 

Pollutants – Particulate Matter (3c of 7) 3X

Pollutants – Particulate Matter (3d of 7): 

Pollutants – Particulate Matter (3d of 7) 4X

Pollutants – Particulate Matter (3e of 7): 

Pollutants – Particulate Matter (3e of 7) 1000X

Pollutants – Particulate Matter (3f of 7): 

Pollutants – Particulate Matter (3f of 7) 5000X

Pollutants – Particulate Matter (3g of 7): 

Pollutants – Particulate Matter (3g of 7) 10,000X

Pollutants – Particulate Matter (3h of 7): 

Pollutants – Particulate Matter (3h of 7) 20,000X

Pollutants – Particulate Matter (4 of 7): 

Pollutants – Particulate Matter (4 of 7) Lava lamp and particles Big particles settle out Many small particles stay suspended for hours

Pollutants – Particulate Matter (5 of 7): 

Pollutants – Particulate Matter (5 of 7) Many compounds are in PM Primary Particles (directly emitted) Secondary Particles (from precursor gases) Composition of PM tells us about the sources and formation processes Gas Particle

Pollutants – Particulate Matter (6 of 7): 

Pollutants – Particulate Matter (6 of 7) PM varies across the U.S. and by season Source: U.S. EPA Air Quality System (AQS) Chicago PM2.5 composition

Pollutants – Particulate Matter (7 of 7): 

Pollutants – Particulate Matter (7 of 7) PM Formation Coagulation: Particles collide and stick together. Chemical Reaction: Gases react to form particles. Cloud/Fog Processes: Gases dissolve in a water droplet and chemically react. A particle exists when the water evaporates. Sulfate

Pollutants – Visibility (1 of 3): 

Pollutants – Visibility (1 of 3) PM affects visibility Visibility is the greatest distance one can see and identify with the unaided eye a dark object against the sky (daytime) or a moderately intense light source (night) Haze is particles suspended in air reducing visibility Visibility is affected by Viewing and sun angle Humidity Particle size, type, and concentration

Pollutants – Visibility (2 of 3): 

Pollutants – Visibility (2 of 3) How do particles affect visibility? Particles interrupt light transmission by: Absorbing light Scattering light Diffracting light Introduction to Visibility, Malm

Pollutants – Visibility (3 of 3): 

Pollutants – Visibility (3 of 3) Examples of PM affecting visibility Burlington, VT October 9, 2001 Burlington, VT June 15, 2001 Chicago Aug 16, 2000` PM2.5 < 10 ug/m3 Chicago, August 26, 2000 PM2.5 = 35 ug/m3 Source: www.mwhazecam.net, www.hazecam.net, and Introduction to Visibility, Malm Glacier National Park PM2.5 7.6 ug/m3 Glacier National Park PM2.5 21.7 ug/m3

Pollutants – Toxics (1 of 2): 

Pollutants – Toxics (1 of 2) Air toxics (hazardous air pollutants) are known or suspected to cause cancer or other serious health effects. 188 hazardous air pollutants include Benzene (motor fuel, oil refineries, chemical processes Perchlorethylene (dry cleaning, degreasing) Chloroform (solvent in adhesive and pesticides, byproduct of chlorination processes) National Air Toxics Emission Sources, 1996 Source: U.S. EPA trends report

Pollutants – Toxics (2 of 2): 

Pollutants – Toxics (2 of 2) Different than criteria pollutants No set criteria (yet) for health concern (except lead) A challenge to monitor Usually not available in real-time Example: Dioxin requires 28 days of sampling to get measurable amounts Often localized near source Difficult to forecast due to Lack of real-time data Local nature

Pollutants – Recap: 

Pollutants – Recap Ozone Reactive, invisible gas Secondary pollutant Forms from NOx and VOCs PM Small solid and liquid particles Composed of many compounds Fine particles (PM2.5) affect visibility and persist in the atmosphere Air toxics Many compounds Growing concern Not yet ready to forecast

Emissions – Categories of Sources (1 of 4): 

Emissions – Categories of Sources (1 of 4) Point – generally a major facility emitting pollutants from identifiable sources (pipe or smoke stack). Facilities are typically permitted.

Emissions – Categories of Sources (2 of 4): 

Emissions – Categories of Sources (2 of 4) Area – any low-level source of air pollution released over a diffuse area (not a point) such as consumer products, architectural coatings, waste treatment facilities, animal feeding operations, construction, open burning, residential wood burning, swimming pools, and charbroilers

Emissions – Categories of Sources (3 of 4): 

Emissions – Categories of Sources (3 of 4) Mobile On-road is any moving source of air pollution such as cars, trucks, motorcycles, and buses Non-road sources include pollutants emitted by combustion engines on farm and construction equipment, locomotives, commercial marine vessels, recreational watercraft, airplanes, snow mobiles, agricultural equipment, and lawn and garden equipment

Emissions – Categories of Sources (4 of 4): 

Emissions – Categories of Sources (4 of 4) Natural – biogenic and geogenic emissions from wildfires, wind blown dust, plants, trees, grasses, volcanoes, geysers, seeps, soil, and lightning

Emissions – NOx (1 of 2): 

Emissions – NOx (1 of 2) Nitrogen oxides are composed of nitrogen oxide (NO) and nitrogen dioxide (NO2) Importance Precursor to ozone Precursor to PM2.5 (ammonium nitrate) NO2 is a criteria pollutant Major sources Vehicles, trucks, boats, engines (52%) Coal, oil, gas, residential wood combustion (43%)

Emissions – NOx (2 of 2): 

Emissions – NOx (2 of 2) 1998 Nitrogen Oxide Emissions Density Source: U.S. EPA National Air Pollutant Emission Trends, 1900-1998

Emissions – SO2 (1 of 2): 

Emissions – SO2 (1 of 2) Sulfur dioxide (SO2) gas is formed from burning fuel containing sulfur (mainly coal and oil). Importance: Precursor to PM2.5 (ammonium sulfates) SO2 is a criteria pollutant Major sources Electrical and industrial fuel combustion (81%) Commercial and residential fuel combustion of coal, oil, gas (6%)

Emissions – SO2 (2 of 2): 

Emissions – SO2 (2 of 2) 1998 Sulfur Dioxide Emissions Density Source: U.S. EPA National Air Pollutant Emission Trends, 1900-1998

Emissions – VOCs (1 of 2): 

Emissions – VOCs (1 of 2) Volatile organic compounds (also called hydrocarbons) are composed of hundreds of gases. Many odors detected are from evaporative pollutants. Importance Precursor to ozone Precursor to PM2.5 (organic carbon) Include toxic compounds Major sources Vehicles, trucks, boats, engines (43%) Solvents (30%)

Emissions – VOCs (2 of 2): 

Emissions – VOCs (2 of 2) 1998 Volatile Organic Compound Emissions Density

Emissions – Primary PM2.5 (1 of 2): 

Emissions – Primary PM2.5 (1 of 2) Particulate matter (less than 2.5 µm) is composed of solid and liquid compounds directly emitted into the air. Importance Primary emissions of PM2.5 Reduces visibility Major sources (primary emissions) Miscellaneous: agriculture crops and livestock activity, wildfires and managed burns; and dust from unpaved roads, construction (66%) Wind-blown dust (9%)

Emissions – Primary PM2.5 (2 of 2): 

Emissions – Primary PM2.5 (2 of 2) 1998 Primary Particulate Matter (PM2.5) Emissions Density

Emissions – Biogenic: 

Emissions – Biogenic Nitrogen oxides 1997 Volatile organic compounds 1997

Pollutant Lifecycles and Trends: 

Pollutant Lifecycles and Trends Lifecyles are daily and episodic changes in pollution levels. Trends are longer-term changes in air pollution that are caused by population and emission changes. Importance Daily forecasting (changes, evolution) Communication (message, exposure) Four time periods Day/night (diurnal) and multi-day Seasonal Yearly Long-term

Lifecycles – Day/Night (1 of 3): 

Lifecycles – Day/Night (1 of 3) Day/night and multi-day changes Local ozone/ PM2.5 measurements at a site affected by: Weather Season Emissions (regional and local) Site location

Lifecycles – Day/Night (2 of 3): 

Lifecycles – Day/Night (2 of 3) Ozone example

Lifecycles – Day/Night (3 of 3): 

Lifecycles – Day/Night (3 of 3) Ozone example

Lifecycles – Multi-day: 

Lifecycles – Multi-day Combined Ozone and PM2.5

Seasonal – Ozone: 

AQI Frequency for ozone Average No. of Days per month Ozone (Sacramento 2000-2003) * * * * * * * All days in January, February, March, April, November, and December were assumed to have “Good” ozone AQI Seasonal – Ozone

Seasonal – PM2.5: 

AQI Frequency for ozone Average No. of Days per month PM2.5 (Sacramento 1999-2002) Seasonal – PM2.5

Slide65: 

AQI Frequency for Ozone and PM2.5 Average No. of Days per month Sacramento Ozone and PM2.5 Seasonal – Ozone and PM2.5

Yearly Trends (1 of 4): 

Yearly Trends (1 of 4) Yearly pollution trends affected by Season (temperature, precipitation, clouds) Emissions changes (substantial) Example: Columbus, OH

Yearly Trends (2 of 4): 

Yearly Trends (2 of 4) Temperature departure from normal vs. maximum AQI 2001 AQI Unhealthy for SG Moderate Temperature above normal Temperature below normal

Yearly Trends (3 of 4): 

Yearly Trends (3 of 4) Temperature departure from normal vs. maximum AQI 2002 AQI Unhealthy for SG Moderate Temperature above normal Temperature below normal Unhealthy

Yearly Trends (4 of 4): 

Yearly Trends (4 of 4) Temperature departure from normal vs. maximum AQI 2003 AQI Unhealthy for SG Moderate Temperature above normal Temperature below normal Unhealthy

Long-Term Trends: 

Long-Term Trends Long-term trends – 5 or more years Affected by Emissions changes Year-to-year weather changes Monitor characteristics changes (location, environment) Metric used to evaluate trends

Emissions and Trends – Recap: 

Emissions and Trends – Recap Emissions Point, area, mobile, natural Sources are everywhere Major pollutants: NOx, VOCs, SO2, PM Trends Diurnal (day/night) – forecasting/communication Seasonal – planning Yearly – communication Long-term – “are we making a difference”

Key Weather Features: 

Key Weather Features “The solution to pollution is dilution (and less contribution)” Discuss how weather features influence air quality Winds Inversions Fronts and air masses Sunlight, clouds, precipitation

Winds – Dispersion: 

Winds – Dispersion How do winds affect pollution? Disperse pollutants – the spreading of atmospheric constituents. Dispersion is a dilution process Molecular Diffusion (not efficient) Atmospheric turbulence Mechanical Shear Buoyancy (convective) Resource: meted.ucar.edu/dispersion/basics/navmenu0.htm

Winds – Transport: 

Winds – Transport How do winds affect pollution? Pollutant transport – Movement of pollutants from one area to another by the wind Types Neighborhood scale: monitor to monitor Regional scale: city to city and state to state National scale: country to country. Global scale: continent to continent Transport of pollution from the Los Angeles Basin to the Mojave Desert (Courtesy of Don Blumenthal)

Neighborhood Scale (1 of 2): 

Neighborhood Scale (1 of 2) 8-hr running averages Peak 1-hr average Afternoon Wind

Neighborhood Scale (2 of 2): 

Neighborhood Scale (2 of 2) 65 101 106

Regional Scale : 

Regional Scale Source: Chinkin et. al., 2003 High pollutant concentrations upstream can be transported into a different area and can cause substantial increases in air quality concentrations than would otherwise occur

National Scale: 

National Scale Transport of smoke from California wildfires in 2003

Global Scale: 

Global Scale Image from http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/OCDST/asian_dust_sequence.html#apr_20 and "The Asian Dust Events of April 1998" by Husar and 28 co-authors (Journal of Geophysical Research - Atmospheres, 106 (D16), 18317-18330, August 27, 2001) discusses these events. Asian dust transport across the Pacific

Wind – Dust: 

Wind – Dust How do winds affect pollution? Create pollution – wind-blown dust Two requirements Dusty land/soil Winds 17 mph can loft dust Source: http://meted.ucar.edu/mesoprim/dust/frameset.htm Threshold Dust-lofting Wind Speed for Different Desert Environments

Dust (1 of 2): 

Dust (1 of 2) Dust event January 3, 2004, 11:00 a.m. to 5:30 p.m., El Paso, Texas Source: TCEQ

Dust (2 of 2): 

Dust (2 of 2) Dust event January 3, 2004, 11:00 a.m. to 5:30 p.m., El Paso, Texas Source: TCEQ

Inversions: 

Inversions Inversions occur when temperature increases with height. Inversions are important because they suppress vertical dispersion of pollution and often trap pollution near the surface where we live.

Inversion – Example: 

Inversion – Example

Inversions – Types: 

Inversions – Types Subsidence Created by sinking air associated with ridges Can limit daytime mixing depth and play important role in daytime pollutant concentrations Nocturnal Created by cooling ground at night Strongest with clear skies, light winds, and long nights Can trap emissions, released during the overnight hours, close to the ground Advection Created when warm air aloft moves over cooler air below Can occur ahead of an approaching cold front Can cause poor air quality, despite the lack of an aloft ridge

Fronts and Airmasses: 

Fronts and Airmasses Fronts are regions where an atmospheric variable (temperature, dew point, etc.) changes rapidly across a small horizontal distance and divide Airmasses

Fronts: 

Fronts What do they do to air quality? They can cause rapid changes in air quality levels within a few hours of passage Weak fronts can have little to no impact of their own; however, enhanced convection that occurs near them can reduce air quality A stationary front positioned near an area is often associated with high PM2.5 levels

Sunlight/Clouds/Precipitation: 

Sunlight/Clouds/Precipitation Affect on PM2.5 and ozone and why

Key Weather Features – Summary: 

Key Weather Features – Summary Winds Disperse pollution Transport pollution Create dust Inversions Trap pollution Fronts and airmasses Boundaries of pollution Sunlight and clouds Influence pollutant chemistry Precipitation No direct impact on PM2.5 or ozone but can wash out PM10

Summary of Air Quality and Meteorology 101: 

Summary of Air Quality and Meteorology 101 Smog – A long polluted history, but improving Types of pollutants Primary Secondary Pollution is everywhere… Ozone – a colorless, reactive gas PM – many small liquid and solid particles Visibility impaired by particles Emission from many sources

Summary of Air Quality and Meteorology 101: 

Summary of Air Quality and Meteorology 101 Lifecycles and trends Day-night changes Seasonal considerations Long-term trends Solution to pollution is both dilution and less contribution Winds disperse, transport, and create pollution Inversions decrease dispersion Fronts – define a change in air mass Sunlight, clouds, and precipitation affect pollution in many different ways

Factoids: 

Factoids An increase in temperature of 18°F can cause over a two-fold increase in biogenic VOC and NO emissions. (http://www.epa.gov/ttn/chief/trends/trends98/chapter6.pdf, U.S. EPA National Air Pollutant Emission Trends: 1900-1998 (March 2000) EPA 454/R-00-002) One part per billion is equivalent to a pinch of salt in 10 tons of potato chips. A part per billion is also one part (salt) per billion parts (chips) or one drop of impurity in 500 barrels of water. (http://ace.orst.edu/info/extoxnet/tibs/partperm.htm). Spilling a “shot glass” (1oz.) of gasoline that evaporates produces the same VOC emissions as a car driving 56 miles (STI). In one day, one acre of eucalyptus trees emits more VOC emissions than a car driving over 7,700 miles (STI). The term “ozone” was suggested by Christian F. Schoenbein in 1840 as an atmospheric constituent gas with a certain odor; the Greek word “to smell” is ozein.

Factoids: 

Factoids “Innovative" solutions proposed by the public for the Los Angeles’ smog problem: Tearing a hole in the atmospheric inversion layer that traps smog—thereby allowing it to escape—by firing cannons through the inversion layer from Mt. Wilson, dropping hot water on it from balloons, or burning a hole through it using giant mirrors focusing the sun's rays. Installing spray towers off the coast to wash air at night as it flows offshore. Seeding clouds to produce cleansing rains. Planting smog-absorbing vegetation on mountain sides surrounding the Los Angeles Basin. (Source: http://www.aqmd.gov/news1/History.htm) Moving air takes energy. The polluted air mass out of Los Angeles County alone (up to 1000 feet) weighs 650 million tons. Electric fans needed to push the air out each day would require the electrical output of the Hoover Dam for eight years. (Dr. Arie Haagen-Smit who discovered the nature and causes of photochemical smog. Source: http://www.aqmd.gov/news1/History.htm)

Slide94: 

Ozone as O3

Slide95: 

Overnight

Slide96: 

Dawn

Slide97: 

Mid-morning

Slide98: 

Noon

Slide99: 

Late Afternoon

Slide100: 

Evening