1 / 63

Ozone in Winter in the Upper Green River Basin

Ozone in Winter in the Upper Green River Basin. Greater Yellowstone Area Clean Air Partnership Meeting October 15, 2008. Jonah/Pinedale 2005. Sublette County Wells. Sublette Co. Gas Production 1980-2007. How Ozone is Formed.

newlin
Download Presentation

Ozone in Winter in the Upper Green River Basin

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ozone in Winter in the Upper Green River Basin Greater Yellowstone Area Clean Air Partnership Meeting October 15, 2008

  2. Jonah/Pinedale 2005

  3. Sublette County Wells

  4. Sublette Co. Gas Production 1980-2007

  5. How Ozone is Formed • Formed through a complex series of reactions between nitrogen oxides and volatile organic compounds driven by sunlight. • Generally thought to occur under sunny, high temperature situations (i.e., summer months in urban areas)

  6. Changes to 8-hr Ozone National Ambient Air Quality Standard • Previous Standard: 3-year average of the 4th highest daily 8-hour averaged ozone concentration = 0.08 ppm • Standard Revised in May 2008: 3-year average of the 4th highest daily 8-hour averaged ozone concentration = 0.075 ppm • The primary (health-based) and secondary (welfare-based) standard were set at the same value

  7. History of Air Monitoring in the Upper Green River Basin • Began ozone monitoring in 2005 • Standard was 0.08 (~0.084) • Found elevated levels: • 4th high 8-hour 0.080 on February 24th • (Yellowstone monitor that day was 0.049) • Confirmed that monitor was functioning properly • Recurred in 2006 • 4th high 8-hour 0.075 on February 27th • (Yellowstone monitor that day was 0.056)

  8. 2005 & 2006 Top 5 8-hour ozone concentrations * Less than 75% data completeness $ Began operation in July 2005

  9. Theories on Causes • Monitoring error • Stratospheric Intrusion • Transport • Locally Formed Jonah 12:00 2/27/06

  10. Theories on Causes - conclusions • Monitoring error: Not Likely • Checked certifications • Additional 3rd party audits • Elevated concentrations at multiple monitors • Winter 2006 put Chemiluminescent ozone monitor at Jonah to check for interference and found none • Stratospheric Intrusion:Not Likely • Tight inversion and stagnant conditions for several days • Transport: Slight Possibility • Other areas had not reported high wintertime conditions

  11. Theories on Causes (cont.) 2005 • Locally Formed: Most Likely • Precursors emitted in area • Suspected tight inversion • Stagnant conditions • Sunny, snow cover

  12. AQD Response to Ozone Events • Concerns about elevated concentrations • Potential for NAAQS violation • Health effects on local public • More development planned in SW Wyoming • Requested proposals for an Ambient and Meteorological Field Study

  13. AQD Initiated an Intensive Field Study in Jan. 2007 • Study Objectives: • Determine meteorological conditions • Identify causes of high ozone • Identify ozone distribution • Identify role of ozone precursors • Develop tools to model ozone formation

  14. 2007 Ozone Monitoring Field Study

  15. 2007 Continuous Measurements • Continued monitoring at Boulder, Jonah, and Daniel South • CastNet continued collecting ozone data • Wind speed with height at airport • Seven temporary stations to measure wind speed, wind direction and ozone

  16. 2007 Intensive Operating Periods (IOPs) • Operational forecasts • Elevated ozone events likely • Trigger Intensive Operating Periods (IOPs) • IOP Measurement Objectives • Determine structure of atmosphere during high ozone events: • How shallow is the inversion? • What does the vertical ozone profile look like? • What differences exist between Jonah, Boulder, Daniel? • Determine spatial variability of ozone concentrations around Upper Green River Basin • Determine VOC concentrations

  17. 2007 IOP Measurements • Temporary equipment to measure upper level winds, temp., relative humidity and ozone at Airport • Aircraft measurements of ozone, temp., VOCs

  18. Summary: 2007 vs. 2005-2006 Weather Patterns • Weather conditions associated with high ozone events in 2005-2006 did not occur during 2007 • Lack of snow cover in 2007 • Stronger upper level winds in study area in 2007 • Stronger surface winds in 2007 • Morning surface inversions did not persist

  19. Meteorology • Why important? • Ozone a secondary pollutant • Ultraviolet light (sunshine) • Temperature inversion

  20. Ozone: Sunlight • UV energy from the sun is required to produce ozone • Historically, scientists believed ozone can’t be formed in low temperatures or areas with low sun angles (i.e., winter) • Study measured UV energy • Result: when ground is highly reflective, UV energy is doubled

  21. Ozone: Sunlight Albedo = 0.81 (snow) Albedo = 0.04 (bare ground)

  22. Preliminary conclusions • In the winter: • Temperature inversion • Still air • Snow cover • Sunshine • Ozone precursors present in UGRB Produce elevated ozone

  23. 2008 Field Study Objectives • Develop a more complete characterization of winter ozone events in the Upper Green River Basin • Provide data for • Development of a conceptual model of ozone formation • More accurate numerical simulations of high ozone events

  24. 2008 Study Approach • Study design based on 2005 & 2006 high ozone event data • Identify meteorological and air quality modeling data requirements • Identify data needed to evaluate initial theories • Develop episode forecasting protocol • Use field study website to post daily forecasts and raw data • Conduct measurements: mid-January – March 2008 • Continuous Measurements to supplement existing network • Intensive Operating Periods (IOPs)

  25. 2008 UGWOS Continuous Sampling • Routine data collection at existing sites (Boulder, Jonah, Daniel South, Pinedale-CASTNET) • Airport operations • Surface ozone • Surface winds • Sodar Site • Upper level winds, temp • Detected inversions • Five temporary surface sites • Wind speed, wind direction and ozone

  26. 2008 UGWOS IOP Measurements • Inversion layer measurement and columnar ozone measurement at airport: 8:00, 11:00, 13:00, 17:00 • VOC/Carbon compounds sampling • Three hour integrated samples at Jonah, Boulder, Daniel: 4:00 – 7:00, 9:00 – 12:00, 14:00 – 17:00 MST • Aircraft grab samples • Aircraft • Morning and afternoon flights • Ozone, PM2.5, Temperature, Pressure

  27. 140 UGWOS Area Max Thunder Basin 120 Campbell Co. Centennial Yellowstone 100 80 75 ppb ppb 60 40 20 0 115 118 121 124 127 130 202 205 208 211 214 217 220 223 226 229 303 306 309 312 315 318 321 324 327 330 Month/Day (MDD) Wyoming Daily Max 8-Hr O3: 2008 UGWOS Study Period

  28. 85 75 Compliments of Shell 2008

  29. 85 75 Compliments of Shell 2008

  30. 2008 Pinedale Airport Vertical Profiles 11 March @ 6:00 pm 12 March @ 4:00 pm Temp O3 No Inversion, no elevated O3 Different wind directions above and below inversion Inversion at 100 m Elevated O3 below inversion Raw data – subject to change

  31. Role of Mixing Heights SODAR Mixing Height Daily Max 8-Hr Avg O3 at Boulder • Elevated O3 when MH < 150 m agl • Note mini-SODAR max range = 250 m agl

  32. Photos from Boulder Visibility Camera Feb. 19, 2008 Feb. 19, 2007

  33. Typical characteristics of high ozone episodes • Extensive snow cover, light winds, clear to partly cloudy skies • Strong, surface based inversion • Precursors trapped in very shallow layer (less than about 150 m) • High morning NOx and VOC • Limited horizontal mixing results in strong spatial gradients • Morning NW to afternoon SE wind reversal • Most common at Jonah; also seen at other sites • Highest ozone nearly always found at Boulder; lowest at Daniel and Cora in 2008

  34. Conditions Conducive to Ozone Formation • The Three S’s: • Surface winds are light • Snow cover is fairly complete • Skies are clear to partly cloudy • And more S’s: • Stable shallow surface layer with strong surface inversion

  35. What’s being done to reduce emissions associated with oil and gas exploration and production?

  36. Ozone Precursor Sources • Drill rigs • Venting and Flaring from Well completion activities • Gas production • Vehicles

  37. Emission controls: Rig Engines • State has no authority to regulate “non-road” sources • BLM’s Jonah Infill Record of Decision enabled NOx reductions improvements to rig – natural gas engines • BLM’s Pinedale Anticline Record of Decision requires operators to drastically reduce NOx emissions

  38. Shell’s Nabors 784 Drill Rig

  39. Insulated Urea storage tank used w/SCR to control NOx emissions from the diesel generators. Urea Tank

  40. Cat 3512 (~1500 HP each) Diesel Generator Stacks w/SCR Note: Typically all 3 generators operate only during the drilling of the first 2,500 feet of each well with 2 generators operating for the rest of the drilling.

  41. Well Completion Emission Controls

  42. Portable 4-Phase Completion Equipment

  43. Ozone Precursor Sources that DEQ Controls • Gas production

More Related