CCOS 2000 Model Intercomparison: Diagnostic Analyses

1. CCOS 2000 Model Intercomparison:Diagnostic Analyses Gail Tonnesen, Zion Wang, Mohammad Omary, Bo Wang University of California, Riverside Bourns College of Engineering Center for Environmental Research and Technology January 27 2002, Progress Report to CARB

2. Integrated reaction rates (IRR) show chemical production and loss in the grid cell where the species reacted. Results shown here as total ppb/day Integrated Process Rates (IPR) show transport, dispersion, emissions, deposition. Have not looked at these terms yet. Process Analysis Outputs for CAMx

3. IRR outputs stored in CAMx CPA file: Total reactivity P(Ox) = P(O3) and oxidation of NO. Radical budget controls P(O3) and sensitivity in urban areas: Radical initiation Radical propagation and termination NOy budget controls P(O3) and O3 sensitivity in rural areas: Conversion of NOx to Inert HNO3, RNO3, PAN. Chemical Process Analysis for CAMx

4. As expected SAPRC99 is “hotter”than CB4: SAPRC99 has greater organic radical production and lower OH+NO2 radical termination. SAPRC99 produces more O3 in urban areas and less in rural areas. Consistent with box model comparisons. Next several plots compare P(Ox) reactivity in CAMx CB4 and SAPRC99 and also show day to day variability in reactivity. CAMx CB4 vs SAPRC99 reactivity

5. CAMx P(Ox) on July 30

6. CAMx P(Ox) on July 30

7. CAMx P(Ox) on July 31

8. CAMx P(Ox) on August 1

9. CAMx P(Ox) on August 2

10. Production of HNO3 by OH+NO2 on July 30

11. Production of HNO3 by N2O5 on July 30

12. Production of RNO3 on July 30

13. Net Production of PANs on July 30

14. Production efficiency P(Ox)/P(NOz)

15. O3 VOC-NOx Sensitivity • Use observation based methods to estimate peak O3 sensitivity to VOC and NOx • Compare grid model with constrained steady state model results. • Use process analysis to estimate P(Ox) sensitivity to VOC and NOx.

16. H2O2/HNO3 for CB4 July 30

17. H2O2/HNO3 for SAPRC99 July 30

18. H2O2/HNO3 for CB4 July 31

19. H2O2/HNO3 for SAPRC99 July 31

20. H2O2/HNO3 for CB4 August 1

21. H2O2/HNO3 for SAPRC99 August 1

22. H2O2/HNO3 for CB4 August 2

23. O3 Sensitivity versus P(O3) Sensitivity

24. Calculated extent using ambient data as average of measured NOx = NO+NO2 and measured NOx = NOy. Calculated model extent as NOx=NO+NO2. Poor agreement between models and data. Need to further evaluate this. Extent Parameter

25. Extent from Ambient O3-NOx data

26. Extent from Ambient O3-NOx data

27. Extent at Parlier Site July 30(NO2 from TDL)

28. Extent at Parlier Site July 31(NO2 from TDL)

29. Extent at Parlier Site August 1(NO2 from TDL)

30. Extent at Parlier Site August 2(NO2 from TDL)

31. Comparsions of CO as a relatively inert tracer Sensitivity run with met pass through for CMAQ Evaluate Vertical Mixing

32. CMAQ has lower conc early morning and higher conc later in the day. Hypothesis: Difference in vertical dispersion CO Conc plots do not appear to support this. Need to further investigate. Model CO Conc Differences

33. Model CO at 5:00 PDT

34. Model CO at 6:00 PDT

35. Model CO at 8:00 PDT

36. Model CO at 10:00 PDT

37. Model CO N-S Slice at 8:00 PDT

38. CMAQ MCIP2 Sensitivity Pass through of MM5 MRF Met data

39. Focus primarily on CAMx with SAPRC99 for the next phase of modeling. Continue to investigate CMAQ Meteorology and vertical mixing, h-diffusion Updated N2O5  HNO3 with aerosols Additional CMAQ runs well be useful for corrobatory analysis. Run both models again if there are substantial changes in emissions. Recommendations

40. Next Steps • Update emissions inventories • Updated Mobile inventory • Corrections to point sources • Resolve discrepancy in emissions processing • CAMx • sensitivity runs with lower model top, approx 4 km to reduce number of vertical layers. • CMAQ • Need aerosol chemistry to use updated N2O5 kinetics • Investigate vertical mixing and horizontal diffusion