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Ozone in Minnesota
- 1. Kari Palmer Clean Air Dialogues WG2 May 11, 2012
- 2. What is Ozone? • A naturally-‐occurring consAtuent of the upper atmosphere protecAng the earth from UV radiaAon • When formed at ground-‐level it causes human health and environmental problems
- 3. Health & Environmental Effects of Ozone • High levels of ozone can have an adverse impact on the lungs • Airway inflammaAon, shortness of breath, coughing, aggravaAon of asthma, emphysema, bronchiAs • Results in increased medicine use, doctor visits and hospital admissions • ParAcularly older adults, children, people who exercise outside • Damages vegetaAon, trees and crops
- 4. Trends in Ozone: Twin CiAes Metro, 1999-‐2011 120% 100% Standard Percent of standard 80% 60% 40% 20% 0%
- 5. MN Ozone ConcentraAons (2009-‐2011) 80 Standard 70 65 62 63 63 62 62 60 61 60 60 59 59 58 58 60 54 Ozone ConcentraAon (ppb) 49 50 40 30 20 10 0
- 7. 2011 Twin CiAes Air Quality Index Days Ozone PM2.5
- 8. Ozone ConcentraAons Across the U.S., 2010
- 9. Ground-‐Level Ozone FormaAon in MN • A chemical reacAon between nitrogen oxides (NO and NO2), oxygen, and volaAle organic compounds (VOCs) • Sunlight fuels the reacAon -‐ at night ozone levels decrease • Hot days above 85˚F • Winds can transport ozone and precursors
- 10. Ozone
- 11. Ozone Chemistry • OH radical is central to ozone and secondary PM chemistry • OH iniAates reacAons of VOCs (and CO) that produce radicals • Radicals interact with NOx (NO and NO2) in sunlight to form ozone • Ozone requires both NOx and VOC precursors
- 12. Ozone FormaAon Normal ozone cycle NO2 + sunlight = NO + O O + O2 = O3 NO + O3 = NO2 + O2 Ozone cycle disrupted by VOCS VOC + OH = RO2 + H2O RO2 + NO = NO2 + RO
- 13. June 6, 2011 Ozone Exceedance
- 14. June 6, 2011 Ozone Event Time Lapse
- 15. Hourly Ozone ConcentraAons Across Minnesota June 5-‐June 7
- 16. Locally Influenced Ozone Event 6/25/2009-‐6/27/2009
- 17. 2008 Emissions of Ozone Precursors VOCs Other fuel Petroleum combusAon storage and 2% Other tranport • VegetaAon-‐55% 2% 1% • Miscellaneous-‐17% Solvent use 7% • Off-‐highway-‐8% Highway vehicles • Snowmobiles, boats, 8% ATVs, etc. Off-‐highway equipment Natural 8% • Highway vehicles-‐8% vegetaAon 55% • Gasoline vehicles Miscellaneous 17% • Solvent Use-‐7% EPA NaAonal Emissions Inventory, 2008 version 2
- 18. 2008 Emissions of Ozone Precursors Nitrogen Oxides Fuel Fuel combusion Other • Highway vehicles-‐39% combusion other 3% industrial 3% 5% • Gasoline vehicles • Off-‐highway-‐23% Metals processing VegetaAon 6% 6% • Railroads, agricultural, Highway construcAon and vehicles 39% recreaAonal equipment Fuel • Electric uAlity fuel combusAon from electrical uAliAes combusAon-‐15% 15% Off-‐highway equipment 23% EPA NaAonal Emissions Inventory, 2008 version 2
- 19. • Slide #19. Very Important! If you Atle this slide “What emissions decreases maoer”? Include the wrioen answer, “We don’t know”. And then say, the Agency Area of ozone formaAon that is VOC-‐limited shrinks through the day 10 am 12 pm 4 pm July 14, 2005
- 20. What Emissions Decreases Maoer? • We aren’t sure • Photochemical modeling can help Area of ozone formaAon that is VOC-‐limited shrinks through the day 10 am 12 pm 4 pm July 14, 2005
- 21. MN Point Source NOX Emission Trends 150,000 125,000 100,000 Tons 75,000 50,000 25,000 0 2006 2007 2008 2009 2010 Other Pulp & paper Refineries Mining Electric utilities Manufacturing
- 22. Take Away Messages • Ozone causes serious health and environmental damage • ConcentraAons are currently below standards and have been decreasing. • Ozone chemistry is complex • Non-‐linear reacAons of NOx and VOCs • Main sources are fuel combusAon • On and off-‐highway equipment, • Electric uAliAes • Natural sources are important • NOx and VOC reducAons may be important
- 23. Thanks to • Cassie McMahon • Margaret McCourtney • Catherine Neuschler