Attribution of Haze

1. Attribution of Haze What Are the Pieces and How Do They Fit? ReasonablE Progress

2. One Possible Recipe • Describe the area • Identify glidepath • Break down problem by pollutant • Where is the pollutant coming from? • In space … source regions • In time … historical trends • Relate these to emissions • Characterize natural component

3. One Possible Recipe • Where is the pollutant going? • Future emission trends • Future (modeled) concentration changes at Class I areas in 2018 • Analyze 2018 emissions and TSSA results • Conduct “what if” scenarios and narrow down strategies • Use model predictions plus all of the above to demonstrate strategies will likely result in reasonable progress

4. Case Studies • Mt. Rainier, WA • Sulfate • Carbon • Carlsbad and Salt Creek, NM • Sulfate • Dust • Nitrate

5. Mount Rainier Baseline (1998-2002) = 19 dv Actual photos available at IMPROVE website (http://vista.cira.colostate.edu/views/) Some photos can be obtained and “made hazier” with WinHaze software.

6. Mount Rainier Presumptive Goal (2018) = 16.5 dv

7. Mount Rainier Natural Conditions (2064) = 8 dv

9. Mount Rainier Aerosol Composition on 20% Worst Days (2000-02) Available at IMPROVE website (http://vista.cira.colostate.edu/views/)

11. Mount Rainier SO4

12. Mount Rainier Back Trajectory Difference Plot For 20% Worst Sulfate Days (2000-2002) On high SO4 days, air comes disproportionately from the west and northwest relative to all days. TSSA and TRA results show no contribution from OR, but sharp gradient near Portland could cause some uncertainty in this finding. Available at Causes of Haze website (http://coha.dri.edu)

13. 2002 Preliminary SO2 Emissions Available at WRAP Attribution of Haze website (http://www.wrapair.org/forums/aoh)

14. Mount Rainier SO4 Trend on 20% Worst Visibility Day (1989-2002) Centralia SO2 cut by 72% Additional permanent reductions occurred at Centralia in 2003. Further reductions will result from Tier 4 nonroad rule by 2010. Approximate natural conditions Note: Because Centralia reductions occur in the baseline period and not the planning period, they would not count towards the 2008-18 reasonable progress demonstration. They do reduce the baseline, slope, and improvement needed in 2018, but the extent depends on whether controls are implemented at beginning or end of baseline period. Available at IMPROVE website (http://vista.cira.colostate.edu/views/)

15. Mount Rainier Carbon • Changing gears

16. Mount Rainier Back Trajectory Difference Plot For 20% Worst Elemental Carbon Days (2000-2002)

17. Mount Rainier Back Trajectory Difference Plot For 20% Worst Organic Carbon Days (2000-2002) Sources of OC appear less confined than EC, consistent with fact that EC is relatively more anthropogenic/urban.

18. Interannual variability of OC not as great as fire variability. Other, more constant sources of OC probably modulating the signal.

19. Carbon has a significant presence in all samples and seasons.

20. Fraction of Carbon that Is Modern or Fossil

21. Fossil and contemporary carbon concentrations correlate. Common factors may include stagnation / accumulation of both types of emissions and/or conversion of gaseous fossil and contemporary carbon to aerosols by oxidants.

22. This correlation implies a common regional source (e.g., smoke) and/or transport from the Seattle area.

23. Increasing OC Trend Decreasing OC Trend

24. Approximate natural conditions

25. “Five years of aerosol data show that most of the 20% worst extinction days occurred during summer months, dominated by sulfates and OMC (Organic Mass by Carbon). Site observers, familiar with conditions at the site, report that this has not been associated with wildland fires over that time. Summertime maxima likely result from greater summertime photochemical secondary aerosol production, as well as longer upwind transport distances that occur during the summertime.” [Causes of Haze website.]

26. Mount Rainier Fine Soil • Quick note

27. Mount Rainier Back Trajectory Difference Plot For 20% Worst Fine Soil Days (2000-2002)

28. Implications for Mount Rainier • Based on a 1998-02 baseline, a 50% reduction in SO4 would be sufficient to meet the presumptive goal • Sources of SO4 seem limitted to western WA, British Columbia, and their coastal areas • Recent reductions at Centralia will reduce WA SO2 emissions by almost half • Another 10-15% reduction should result from nonroad fuel regulations effective by 2010 • Harbor emissions from vessels fueled outside the U.S. are being addressed

29. Implications for Mount Rainier • Treatment of Centralia reductions in baseline and/or reasonable progress demonstration should be addressed. • Recommendations for further SO4 analysis • TSSA and TRA-based contributions from the Portland, OR area should be carefully evaluated given the steep gradient in that area • Emissions from British Columbia are potential contributors. TRA predicts a 20% contribution. TSSA predicts no contribution. • Representativeness

30. Implications for Mount Rainier • Carbon is 2nd largest contributor to haze • Major source areas appear to be western WA, central OR, and British Columbia • Correlations with Seattle OC imply transport and/or common regional sources (e.g., smoke) • At least 20% of carbon appears to be fossil • Additional carbon aerosols may be formed by anthropogenic oxidation of biogenic VOCs

31. Implications for MORA • Carbon has been decreasing. Coincidental decrease in ozone implies a possible link to anthropogenic emission reductions, which are expected to continue. • Portland carbon data should be folded in. • The source regions and trends of SO4 and carbon, and their apparent response to ongoing anthropogenic emission reductions provide a weight of evidence that presumptive goals for 2018 will be met

32. CarlsbadMonitor located at Guadalupe Mtns in Texas • SO4 • NO3 • Dust

34. Carlsbad Aerosol Composition on 20% Worst Days (2000-02)

36. Back Trajectory Difference Plots For 20% Worst Sulfate Days (2000-2002) San Pedro Carlsbad Source regions for SO4 shift from west to east for sites in the Southeas part of the WRAP region.

37. 2002 Preliminary SO4 Simulation

39. Carlsbad Nitrate • Changing gears

40. Salt Creek Had the 3rd Highest NO3 Concentration In the WRAP Region, Outside CA

41. Salt Creek Back Trajectory Difference Plot For 20% Worst Nitrate Days (2000-2002)

42. Carlsbad Back Trajectory Difference Plot For 20% Worst Nitrate Days (2000-2002) Data from multiple sites may be useful to “triangulate” source regions.

43. Although Salt Creek and Carlsbad share a common source region and are located relatively close to one another, Salt Creek NO3 is much higher and the correlation is not good. Thus, the source region does not affect both simultaneously (i.e., alignment with wind direction), and/or Carlsbad is further downwind.

44. 2002 Preliminary NOx Emissions Oil & Natural Gas Production

47. Trends in Annual Average NO3 Extinction

48. Nitrate Trends in Precipitation

50. Carlsbad Dust • Changing gears