1. V:\corporate\marketing\overview.ppt Baton Rouge 8-hr Ozone Modeling Technical Review Meeting Presentation to the LDEQ/AQSD & 8-hr Ozone SIP Coalition July 27, 2006

2. V:\corporate\marketing\overview.ppt Today’s Presentation Conceptual Model of 8-hr Ozone Episode Analysis Modeling System Modeling Domain Emission Inventory Development –Area & Point Sources –Motor Vehicles (on-road & off-road) –Biogenics & Fires

3. V:\corporate\marketing\overview.ppt Today’s Presentation Initial/boundary conditions Use of Probing Tools

4. V:\corporate\marketing\overview.ppt Conceptual Model Baton Rouge is a Marginal 8-hr Ozone nonattainment area –Single 2003 exceedance DV: LSU = 86 ppb –Four 2005 exceedance DVs: LSU = 96 ppb –2006 exceedances: Will not attain standard by June 2007 as required

5. V:\corporate\marketing\overview.ppt Conceptual Model –Likely “bump-up” to Moderate area Attainment date: June 2010 Spatial distribution –Four key exceedance monitors LSU, Baker, Carville, Port Allen Aligned south-to-north along river Other monitors mostly outside & south of Baton Rouge –Likely interaction between urban, industrial, and biogenic emissions

6. V:\corporate\marketing\overview.ppt Conceptual Model

7. V:\corporate\marketing\overview.ppt Conceptual Model Temporal distribution –Diurnal: classic 12 – 4 PM peaks Evidence of ozone cloud transport site to site No obvious late AM ROFEs or THOEs Possible early PM ROFEs or THOEs –Weekly: no clear-cut weekday/weekend dependencies – more analysis needed –Seasonal: trends toward late spring, early fall multi-day, multi-site episodes In last few years, mid-summer episodes are typically 1-day, few sites

8. V:\corporate\marketing\overview.ppt Conceptual Model

9. V:\corporate\marketing\overview.ppt Conceptual Model Weather requirements –Stagnation, light/variable winds under high pressure Exceedances independent of wind direction –Clear skies –Temperatures do not need to be hot Many exceedances in low 80’s F Emissions-driven, not heat-driven –Few prolonged hot summer episodes Excessive PBL venting or Gulf breeze? Recent interannual climate?

10. V:\corporate\marketing\overview.ppt Conceptual Model Regional transport –Needs 2-3 day transport times Recent summer episodes are too short Some multi-day episodes are clearly caused by local stagnation, re-circulation Some multi-day episodes establish consistent transport corridors from midwest, Ohio Valley, south-east U.S. –Choose episodes that represent mix of conditions Season, meteorology, transport, WE/WD

11. V:\corporate\marketing\overview.ppt Episode Analyses Screened 14 episodes from 2000- 2004 –2005 de-emphasized Concern about availability of emissions data Reduced to 6 candidates –Max exceedance monitor-days at 4 key monitors –Min number of modeling days –Different times of year –Recent episodes

12. V:\corporate\marketing\overview.ppt Episode Analyses 6 candidates –May 19-30, 2003 (M, Sa, W, Th) –September 28-30, 2004 (W, Th) –April 12-30, 2003 (Su, M, F, Su, M, Tu) –October 4-6, 2003 (Sa, Su) –May 4-9, 2004 (Tu, W, Th, Sa) –August 11 – September 5, 2000 (F, Su, Th, F, Sa, Su, M, F, Sa, W, Th, F, Sa, Su)

13. V:\corporate\marketing\overview.ppt Episode Analyses Comparison to CART analysis Bin 10 (22%) Bin 20 (24%) Bin 25 (33%) Bin 27 (10%) Bin 35 (11%)

14. V:\corporate\marketing\overview.ppt Episode Analyses Final 2-3 episodes need to be selected from 6 candidates –Input from advisory group –Consider schedule, resources, and pre- existing datasets –July 31 draft Protocol documents conceptual model for each of 6 episodes

15. V:\corporate\marketing\overview.ppt Episode Analyses

16. V:\corporate\marketing\overview.ppt Episode Analyses

17. V:\corporate\marketing\overview.ppt Episode Analyses

18. V:\corporate\marketing\overview.ppt Episode Analyses

19. V:\corporate\marketing\overview.ppt Episode Analyses

20. V:\corporate\marketing\overview.ppt Episode Analyses

21. V:\corporate\marketing\overview.ppt Modeling System MM5 – Meteorological Model –Widely used to support regulatory modeling EPS3 – Emissions Processor –LDEQ is familiar with EPS CAMx – Air Quality Model –Widely used to support regulatory modeling in south-central U.S. –Full Chemistry PiG allows evaluation of HRVOC plumes

22. V:\corporate\marketing\overview.ppt Domain Configuration Regional grid (36 km) based on TCEQ Intermediate grid (12 km) captures transport from Midwest and Southeast Local grid (4 km) along Gulf Coast, including Houston Vertical grid based on St. Louis modeling

23. V:\corporate\marketing\overview.ppt Domain Configuration

24. V:\corporate\marketing\overview.ppt Domain Configuration

25. V:\corporate\marketing\overview.ppt Domain Configuration

26. V:\corporate\marketing\overview.ppt Emission Inventories Start-point inventories: –2002 CENRAP Base B –2002 VISTAS Base G –2002 MRPO Base K –TCEQ inventories and other datasets Useful for August/September 2000 episode Replace CENRAP data for Texas when available for other years?

27. V:\corporate\marketing\overview.ppt Emission Inventories –2000-2005 LDEQ data, as available Stationary point, area On-road: VMT, MOBILE6 Non-road: NONROAD

28. V:\corporate\marketing\overview.ppt Emission Inventories Inventory projections –Specific modeling years (2000-2004, 2009) Regional: based on RPOs, EPA, and TCEQ Local: future year projections are challenging due to recent events –EGU and other large sources: Use CEM as available for base case model performance evaluation Use “typical” inventory rates for projected base and future years

29. V:\corporate\marketing\overview.ppt Emission Inventories Biogenics from GloBEIS –All grids, episode-day specific –Driven by: MM5 and/or temperature observations Satellite PAR data Land cover/biomass data (GIS, etc.) –Held constant into 2009 future year Fires (wild, agricultural, prescribed) –As needed, as available

30. V:\corporate\marketing\overview.ppt Initial/Boundary Conditions Only needed on 36-km grid Use 2002 VISTAS model output fields –Derive monthly-average diurnally-varying IC/BCs for base case episodes Use 2009 VISTAS model output fields –If available, as described above –Otherwise, use 2002 fields

31. V:\corporate\marketing\overview.ppt CAMx Probing Tools Ozone Source Apportionment Technology (OSAT) –Determines source area/category contribution to ozone anywhere in the domain –Tracks NOx and VOC precursor emissions, ozone production/destruction, and initial/boundary conditions –Estimates ozone production uner NOx- or VOC limited conditions

32. V:\corporate\marketing\overview.ppt CAMx Probing Tools OSAT –HOWEVER: it cannot quantify ozone response to NOx or VOC controls –Chemical allocation methodologies: OSAT: standard approach APCA: attributes ozone production to anthropogenic (controllable) sources only GOAT: tracks ozone based on where it formed, not where precursors were emitted

33. V:\corporate\marketing\overview.ppt CAMx Probing Tools PM Source Apportionment Technology (PSAT) –Parallel to OSAT operation –Tracks user-defined groups of species for sulfate, nitrate, ammonium, SOA, Mercury, and primary PM

34. V:\corporate\marketing\overview.ppt CAMx Probing Tools Decoupled Direct Method (DDM) for sensitivity analysis –Calculates first-order concentration sensitivity to emissions, initial/boundary conditions –Allows estimates of effects of emission changes –Allows ranking of source region/ categories by their importance to ozone formation

35. V:\corporate\marketing\overview.ppt CAMx Probing Tools DDM –Slower than OSAT, but: Provides information for all species (not just ozone) More flexible in selecting which parameters to track Better estimate of small emission perturbation impacts (e.g., control measures) Includes sensitivity from non-linear secondary effects

36. V:\corporate\marketing\overview.ppt CAMx Probing Tools Process Analysis (PA) –Designed to provide in-depth analyses of all physical and chemical processes operating in model –Operates on user-defined species and any portion of the modeling grid –Appropriate for evaluating base case performance –Recent UNC enhancements

37. V:\corporate\marketing\overview.ppt CAMx Probing Tools PA –Three components: Integrated Process Rate (IPR): provides detailed process rate information for each physical process (emissions, advection, diffusion, chemistry, deposition) Integrated Reaction Rate (IRR): provides detailed reaction rate information for all chemical reactions Chemical Process Analysis (CPA): like IRR, but designed to be more user-friendly and accessible

38. V:\corporate\marketing\overview.ppt CAMx Probing Tools Reactive Tracers (RTRAC) –Tracks multiple independent reactive gas and particle tracers Tracers operate in parallel to the CAMx host model Allows for several generations of products Decay/production uses standard gas-phase mechanism photolysis and oxidants Can output tracer decay rates to a separate Lagrangian model for “fenceline” dispersion calculations

39. V:\corporate\marketing\overview.ppt CAMx Probing Tools RTRAC –Designed for primarily for air toxics Assumes RTRAC species have minimal impact on photochemistry Each tracer can be “tagged” for source apportionment –RTRAC works with IRON PIG An optional “sampling grid” capability passively samples near-source sub-grid RTRAC surface concentrations within reactive PiG plumes