1. CRGAQS: Latest CAMx 2018 Results R2
Presentation to the
Gorge Study Technical Team
ENVIRON International Corporation
Alpine Geophysics, LLC
May 23, 2007

2. Today’s Presentation Review 2004 extinction against IMROVE
Review modeled organic carbon components
Show revised nephelometer comparisons
Account for high humidity in November episode
Latest 2018 CAMx simulations
Review results for August episode
Compare 2004, 2018 and 2018 What-if’s
Review results for November episode
Trend lines
Next Steps

3. 2004 Extinction vs IMPROVE

4. 2004 Extinction vs IMPROVE

5. CAMx Organics Primary organic aerosol (POA)
Sources: any combustion
Emitted as a stable aerosol
No evaporation/re-condensation
Secondary organic aerosol (SOA)
VOCs oxidize to condensable gases
SOA forms as f(T, RH, aerosol mass)
Condensation/evaporation possible

6. CAMx Organics CAMx treats 5 kinds of SOA
SOA1-3 from anthropogenic VOC sources
Tracks formation from aromatics and parafins
Combustion and fugitive sources
SOA4-5 from biogenic VOC
Terpenes generate two SOA products
Less apt to evaporate
Updates coming for both CAMx and CMAQ
Sesqueterpenes and isoprene

7. 2004 vs Results (August)

8. 2004 vs Results (August)

9. 2004 vs Results (November)

10. 2004 vs Results (November)

11. November Nephelometer

12. November Nephelometer

13. What-if Scenarios Case 01 – zero Boardman emissions
Case 02 – zero NH3 emissions for PSAT region 5 (east of Gorge)
Case 03 – zero on-road mobile source emissions for PSAT region 2 (Portland and Vancouver)
Case 04 – zero major point source emissions for PSAT region 2
Case 05 – zero major point source emissions for PSAT region 1 (in-Gorge)

14. PSAT Regions

15. 2004 vs Results (August)

16. 2004 vs Results (August)

17. Calculation of Trend Lines
2004 to 2018 trend in extinction
Average daily extinction over “high” days
August Episode
August at Mt Zion
August 12-15, 19 at Wishram
November Episode
November 6,8,9,13,16 at Zion
November 8,10-14 at Wishram
Calculate “Deciview” from extinction
Linearizes extinction effect on visual range
DV change of ~1 is “just perceptible” change in visibility

18. August Trend Lines -0.44 Mm-1 per year -0.07 per year -6.2 Mm-1 -10%
-1.0
-0.22 per year
-3.1
-0.99 Mm-1 per year
-13.9 Mm-1
-27%

19. 2004 vs Results (November)

20. 2004 vs Results (November)

21. November Trend Lines -0.07 per year -2.42 Mm-1 per year -1.0
-9%
-0.12 per year
-1.7
-3.67 Mm-1 per year
-51.4 Mm-1
-15%

22. Next Steps Apply modeled changes to observed levels
Finish PSAT (2004/2018, August/ November)
Complete report