OTC Modeling Committee April 2015 Update

Presented by: Dan GoldbergThursday April 9th, 2015

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 conditionsPreliminary work by Dan Goldberg, University of Maryland, please contact prior to use

3Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

4Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

5Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

6Preliminary work by Dan Goldberg, University of Maryland, please contact prior to use

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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

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

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• 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 O3 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

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• 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

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• 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

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• 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

12Peak in biogenic O3 at this time is probably due to O3 being formed in a VOC-limited environment due to NOx saturation because the the PBL is still low

Unsure why this portion is so large, perhaps also due to O3 being formed in a VOC-limited environment over the bay (which would be attributed to anthropogenic VOCs, not isoprene)

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

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

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

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O3 Attributed to a VOC-limited environment in mid-afternoon July 2011 (Baseline)

• Some areas have > 50% VOC-limited O3 , is this really the case??? • Observations show NOx reductions are reducing O3 (Salawitch, Loughner)

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O3 Attributed to a VOC-limited environment in mid-afternoon July 2011 (Beta)

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

• “Beta” work shows a much lower % of VOC-limited O3

Beta Run:- CB6r2- MEGANv2.1- 50% mobile NOx emissions

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• 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 emissionsPreliminary work by Dan Goldberg, University of Maryland, please contact prior to use

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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

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