1. WAQS Source Apportionment Modeling Update Ralph Morris IWDW/WAQS Technical Committee January 12, 2016 Fort Collins, Colorado 1

2. 2 Content: Source Apportionment (SA) Overview of WAQS Source Apportionment Plan – Round 1 – Geographic (done) – Round 2 – Source Sector (done) – Web-based SA Visualization Tool (in progress) – Round 3 – Detailed 4 km SA (not started) Preliminary Results (Round 1) Visualization Tool Status (Update) Updates to CAMx SA Tool (information) Potential Approaches for Round 3 (feedback)

3. R1: Geographic Source Apportionment 2011a Emissions 21 Source Regions 5 Source Categories – Natural (Bio, Lx, SS, WBD) – 3 Fires (WF, Rx, Ag) – Remainder Anthropogenic Ozone/APCA 36/12 km PSAT/PM 36 km O3, PM, Vis and Dep Contribution CSAPR-type Analysis RHR Impaired vs. W20% Days

4. R2: Source Sector Apportionment 2011b Emissions Source Categories: – Natural (Bio, LNOx, SS, WBD) – Wildfires (WF) – Rx+Ag Fires – O&G – EGU Point – Other Point – On-Road – Non-Road – Remainder Anthro Five Source Regions – CO, UT, WY and NM – Remainder

5. R3: Detailed 4 km SA Examine local source contributions in more detail, possibilities: – Episodic period(s) from 2011 – State subregions – Source subcategories Will discuss in more detail at end of this PPT – Request feedback from Technical Committee 5

6. 6 R1 Results: CASPR-Type Analysis Run Model Attainment Test Software (MATS) using CAMx base output and output from each State’s anthropogenic emissions removed – Anthro = Anthropogenic + Rx and Ag fires – Provides State’s contribution to Design Values 8-Hour Ozone and 24-Hour and Annual PM2.5 CASPR-type analysis – User selects level of NAAQS and Upwind State – Spread sheet performs analysis summarizing Downwind States where the Upwind State contributes significantly Significance defined as 1% of the NAAQS 6

7. Drop Down Menu for Upwind State and Level of NAAQS

8. Downwind States where the Upwind State (CO) Contributes Significantly to Ozone Nonattainment in a Downwind State under 70 ppb Ozone NAAQS 8

9. Source Contributions at Downwind States 9

10. 10 Web-Based SA Visualization Tool Received comments on Prototype that was based on 2008 WestJumpAQMS top highest modeled 8-hour ozone days – Biggest comment was to extract SA information at more locations than just the monitoring networks – Added virtual gridded network covering western U.S. at 36 km resolution Updated SA Vis Tool with WAQS R1 Geographic ozone SA results for every day of year 10

11. 11 WAQS Receptors for Data Extraction 11 Ozone PM

12. Ozone Vis Tool Opening Page

13. Site Selection: Dropdown or Map Day Selection: Dropdown or Calendar 13

14. AQS Network Locations 14

15. Map Browser 15

16. Day Selection 16

17. 17 Add Time Series SA Capability

18. 18 Updates to CAMx Source Apportionment Tool OSAT – apportion ozone changes (ΔO 3 ) to tracers O3N and O3V APCA – only assign O3 formed to biogenic when due to interactions of biogenic VOC and biogenic NO X (policy relevant) “OSAT2” – simultaneously treat O 3 production and destruction “OSAT3” – treat odd oxygen in NO 2 and NO X recycling

19. Improve OSAT algorithms Track odd-oxygen through NO 2 – When NO 2 accumulates, e.g., overnight in urban cores – Requires NO 2 apportionment Track NO X recycling – Source of NO X where emissions are low – Apportion HNO 3 (etc.) which PSAT does – Must apportion O and N in NO 2 independently Odd-oxygen in NO 2 (ONO) Follow the O: NO + OOO  ONO ONO + hv  NO + O O + OO  OOO NO X recycling Follow the N: OH + NO 2  HNO 3 HNO 3 + hv  OH + NO 2 also for PAN and nitrates Purpose of OSAT Update Content slide

20. 20 OSAT (1995-2004) OSAT uses 4 Reactive Tracers for each Source Group: – N i -- Nitric oxide (NO) and nitrogen dioxide (NO 2 ) emitted by source group i – V i -- VOC emitted by source group i – O3N i -- O 3 formed under NO X -limited conditions from N i – O3V i -- O 3 formed under VOC-limited conditions from V i NO X - vs. VOC-limited determined by ratio of instantaneous production of hydrogen peroxide and nitric acid – [PH 2 O 2 ]/[PHNO 3 ] < 0.35  NO X -limited (Sillman, 1995) When total change in ozone (ΔO3) is positive, allocate ΔO3 to Source Groups based on contribution of limiting precursor (N or V) When ΔO3 is negative, detriment Source Groups O3N and O3V equally on total percentage basis 20

21. 21 OSAT2 (2005-2015) OSAT2 recognizes that ozone formation and destruction can occur at the same time Calculate ozone destruction (DΔO 3 ) due to reactions: – O 3 + VOC reactions since these remove ozone; – O( 3 P) + VOC reactions since these effectively remove ozone; – O( 1 D) + H 2 O reaction since this effectively removes ozone; – HO X + O 3 reactions that do not re-form ozone. Ozone formed PΔO 3 = [ΔO 3 – DΔO 3 ] Allocate PΔO 3 and DΔO 3 to Source Group reactive tracers using same reactive tracers and rules as OSAT

22. 22 OSAT3 (2015+) Track odd oxygen and nitrogen recycling Need many more (10) reactive tracers than OSAT/OSAT2 (4): – V i VOC emitted by source group i – NIT i Nitric oxide (NO) and nitrous acid (HONO) – RGN i Nitrogen dioxide, nitrate radical (NO 3 ) and dinitrogen pentoxide (N 2 O 5 ) – TPNiPeroxyl acetyl nitrate (PAN), analogues of PAN and peroxy nitric acid (PNA) – NTRiOrganic nitrates (RNO 3 ) – HN3iGaseous nitric acid (HNO 3 ) – O3N i O 3 formed under NO X -limited conditions from N i – O3V i O 3 formed under VOC-limited conditions from V i – OON i Odd-oxygen in NO 2 formed from O3N i – OOV i Odd-oxygen in NO 2 formed from O3V i Also update PSAT with more tracers to be consistent with OSAT3

23. OSAT2 vs. OSAT 3 Comparison

24. OSAT2 vs. OSAT 3 Comparison of Local Contributions 24

25. Updates to Ozone Source Apportionment OSAT3 completed and operational – Apportions odd-oxygen in NO 2 – Tracks NO X -recycling OSAT3 uses more tracers – Larger output, slower runs Contributions change – Generally smaller local contribution – Generally larger transported contribution NO 2 explicitly tracked as own tracer species – Can now do explicit contributions for 1-hour NO 2 assessments instead of using RGN species PSAT also updated – N tracking compatible with OSAT3 Publicly released with next version of CAMx (V6.3?) in 2016 25

26. 2011 Detailed 4 km Apportionment SA Plan presents several possibilities: – Summer ozone SA with more geographic subregions and source subcategories – Winter ozone period – PM2.5 or visibility events New ideas: – OSAT3/PSAT3 – Other??? Limited by available resources