1. OTC Modeling Committee April 2015 Update Presented by: Dan Goldberg Thursday April 9 th, 2015

2. Description of model used: CAMx v6.10 (12 km OTC model domain) – Date range: May 26 – August 31, 2011 – 10 days spin-up – CB05 Gas-phase chemistry (transitioning to CB6r2) – Anthropogenic Emissions: Baseline 2011 & 2018 NEI v1 from EPA – Biogenic Emissions: BEIS v3.14 from EPA – Meteorology: WRF 2011 CONUS 12 km from EPA – Boundary conditions: GEOS-Chem 2011 from EPA Sensitivity studies with: CB6 & CB6r2 gas-phase chemistry, MEGAN v2.10 biogenic emissions and MOZART-4 boundary conditions Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

3. 2

4. 3

5. 4

6. 5

7. Sector-by-Sector Analysis July 1 through July 8, 2011 only (so far) – Will conduct the same analysis for 2018 CAMx OSAT is working as coded to do, but perhaps some caveats in the results 6 Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

8. 7 Peaks in “Biogenic” ozone are near city centers and areas with low boundary layers Air masses near city centers are NOx-saturated in the model, which attributes O 3 to biogenic VOCs Note peak in the Chesapeake Bay and coastal areas downwind of NYC “Biogenic” ozone in rural areas is 6 – 8 ppb, this value is likely closer to reality Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

9. 8 Peaks in “Mobile” ozone are near city centers and interstates Values are highest in North Carolina, lowest in Canada Chicago & NYC do not show up, perhaps due to unfavorable meteorology during early July 2011 Values are likely overestimated due to Anderson et al., 2014 Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

10. 9 Peaks in “EGU” ozone are focused in the Ohio River Valley Values are 6 – 10 ppbv in the Ohio River Valley, lower elsewhere Values are likely underestimated due to Anderson et al., 2014 & Canty et al., 2015 Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

11. 10 Peaks in ozone attributed to everywhere else are focused over the Great Lakes & Atlantic Ocean Still trying to determine the cause of this… Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

12. 11 Peak in biogenic O3 at this time is probably due to O 3 being formed in a VOC-limited environment due to NO x saturation because the the PBL is still low Unsure why this portion is so large, perhaps also due to O 3 being formed in a VOC-limited environment over the bay (which would be attributed to anthropogenic VOCs, not isoprene)

13. 12 Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

14. 13 Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

15. 14 Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

16. O 3 Attributed to a VOC-limited environment in mid-afternoon July 2011 (Baseline) 15 Some areas have > 50% VOC-limited O 3, is this really the case??? Observations show NO x reductions are reducing O 3 (Salawitch, Loughner)

17. O 3 Attributed to a VOC-limited environment in mid-afternoon July 2011 (Beta) 16 Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use “Beta” work shows a much lower % of VOC-limited O 3 Beta Run: - CB6r2 - MEGANv2.1 - 50% mobile NO x emissions

18. 17 New Beta simulation attributes 30 – 40% more ozone to EGUs than the baseline simulation; emissions of EGUs remain the same in each simulation. The increase in attribution to EGUs is due to changing gas-phase chemistry and the nonlinearities associated with changing the biogenic & mobile emissions Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

19. Conclusions Can develop state-by-state source apportionment plots for any source receptor location in the eastern U.S. – Boundary ozone consistently plays a large role in all locations Sector-by-sector source apportionment is working as coded, but several caveats so far – UMD Beta work should improve this 18 Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use