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Expanded Ozone Forecast Guidance for the National Air Quality Forecast Capability

Expanded Ozone Forecast Guidance for the National Air Quality Forecast Capability NWS/NCEP/EMC & NOAA/OAR/ARL - EPA September 18, 2007. Acknowledgements. NCEP/EMC Pius Lee – System design and implementation Marina Tsidulko – PBL & Chem Verification

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Expanded Ozone Forecast Guidance for the National Air Quality Forecast Capability

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  1. Expanded Ozone Forecast Guidance for the National Air Quality Forecast Capability NWS/NCEP/EMC & NOAA/OAR/ARL - EPA September 18, 2007

  2. Acknowledgements • NCEP/EMC • Pius Lee – System design and implementation • Marina Tsidulko – PBL & Chem Verification • Youhua Tang – Regional In-line testing (OAR/GSD) • Ho-Chun Huang – Global dust/smoke system DT&E (NASA, NESDIS) • Sarah Lu – Global data assimilation and feedback testing (NASA, NESDIS) • Brad Ferrier, Dan Johnson – WRF retrospective run • Eric Rogers, Hui-Ya Chuang – NAM products • Jeff McQueen – EMC AQ model team leader • EPA AQ Forecast team (Mathur, Kang, Lin, Yu…)

  3. 2007 Developments • WRF upgrades • Land use/Roughness length corrections: reduce Pac. NW high moisture bias • Enhanced horizontal diffusion on sloping terrain • CMAQ Improvements • Common NMM vertical coordinate • Asymmetric Convective Model (ACM-2) PBL parameterizations • Area & Point emissions updated for 2007 • California 2002 NEI emissions modified for biases • Corrections to deposition velocity & plume rise calculations • AQF system retrospective & Real-time testing • July 22- Aug 5 2006 with experimental CONUS configuration • Verification • Spatial map comparisons to observations (03 & PBL hgt) • Inclusion of NESDIS GASP AOD products • Focus group, TEXAQS06 & SHENAIR projects

  4. Forecast Domains (2005-2007) 259 grid cells • CONUS “5x” Domain • WRF-CMAQ • WRF-CMAQ/PM East “3x” Domain 268 grid cells

  5. 2006-2007 SystemsNAM/WRF-CMAQ 48 h forecasts

  6. NAM-CMAQ Coupling

  7. Summer 2007 Evaluations(Errors not uncovered w/retro tests) • Experimental/Developmental Runs:Significant under-prediction in upper Mid-West • Deposition Velocity • Added Mesophyll component for O3, NO, NO2 • STATUS: Implemented inexper/dev runs on July 22 • Minor impact on forecast Increased photochemistry in Midwest • Plume Rise • STATUS: Corrected in exper/dev run on July 22 • minor impact

  8. EMC Products1h, 8h avg O3 / Daily Max/ hourly biases

  9. EMC Web Products1h, 24h avg hrly & Max PM & Profiles

  10. EMC Web ProductsNear Real-time Verification CMAQ vs GASP AOD CMAQ 8 h Max Ozone HYSPLIT vs NESDIS Smoke Conc

  11. Daily 8hr max Ozone BiasesOp vs Exp over Eastern U.S. Summer 2006 (after NAM upgrade) Summer 2007 • Both Op and Experimental Runs improved in 2007 • For Operational run, NAM improvements partially responsible

  12. Daily 1 & 8h Max Ozone Skill Scores2007 Operational (3X) vs Experimental (5X) Equitable Threat Score ~ H/(O+F-H) 1hr Avg Thresholds (ppb) 8 hr Avg Thresholds (ppb) Experimental: - Better performance at low/moderate ranges & in East U.S. - Comparable at high thresholds

  13. Verification Sub-domains SW Coast includes both LA, SD & SJV

  14. Regional Performance, 1-h O3Experimental Run Bias Reduced in 2007 2006 2007 • 2006 • High bias, up to +25 ppb • Underprediction SW coast • 2007 • Bias reduced • Good forecast for NW coast • Underprediction SWC (LA basin)

  15. Regional Performance, 1-h O3Experimental Bias Improved Over Operational Run Operational Bias 2007 Experimental Bias Experimental Bias improved over operational system over all regions

  16. California Air Districts

  17. California Performance Good: SJV Under: LA Over: SAC, East of LA Good: SJV Under: LA Over: SAC, East of LA Good: SAC, SJV Under: LA Over: East of LA

  18. NAM vs RTMA 10 m WindsJuly 3rd 5 PM, 36 hour Forecasts RTMA NAM LA Basin: NAM Temps are warmer; winds are stronger & more westerly

  19. NAM 2m Dew point ErrorsSW Coast (green triangles) BIAS for each day BIAS by Forecast hour

  20. W-E NOx cross-section thru LA Basin 36 hour forecast: July 3, 2007 5 PM July 5, 2007 5 PM Land ocean Lofting of plume above boundary layer can allow further transport of pollutants East of LA

  21. Mid-Atlantic 8h Max Performance July 9, 2007 NAM –RTMA: 2 m T NAM is slightly cooler than observed in PA andW. NJ Continued overprediction along CT coastal regions

  22. Mid-Atlantic 8 h Max Performance July 10, 2007 Very Similar performance between operational and experimental

  23. Mid-Atlantic 8 h Max Performance July 10, 2007 NAM 3h Precip Prediction Precip Analysis Convective precip started earlier than predicted in Mid-Atlantic

  24. 8h Max Ozone Regional PerformanceAugust 7, 2007 Operational Experimental Over-prediction in both runs: cloud cover timing ?

  25. Exp 8h Max Texas PerformanceAugust 11, 2007 OPERATIONAL 12Z 8/10/07 NAM-CMAQ 36 h forecast 5x-3x NOx differences & H20v EXPERIMENTAL • Ozone buildup over stable marine layer w/ 5X. This residual layer can recirculate onshore. Not as strong in 3X. • Inconsistent met & chemical boundary layers

  26. Exp – Op Ozone Difference 12 Z August 10, 2007 Forecast ocean Land

  27. Summary • Overall results • Experimental biases are much improved • NAM changes from 2006 to 2007 also have a positive impact (as Operational run biases improved) • Skill scores are improved at lower levels and comparable at higher thresholds • Experimental run provides previously unavailable guidance to Western U.S. • California O3 forecasts improved • Better performance in San Joaquin Valley • Underprediction in LA urban area • Some Overprediction in Sacramento Valley & downwind of LA • NAM onshore winds near LA often too strong • Spurious upward lofting partially due to inconsistent NAM and CMAQ daytime unstable PBL physics (Vertical resolution may also have an impact) • 5X overprediction along coastal urban areas • ACM-2 stable, marine PBL mixing may be too weak • Produces pollutant reservoir off-shore that can impact coastal urban areas (Houston, Long Island Sound, Lake Michigan…)

  28. Recommendations • Implement consistent boundary layer and cloud mixing schemes • Internal boundary layer processes near coastal regions • Increase focus on chemical data assimilation in Global GSI • Improve coordination with AQF ESRL/GSD data assimilation • LA Basin • NMM high resolution experiments in coordination with ESRL/ PSD NMM study • More complete chemistry • CB05 more heterogeneous chemistry with aerosols • Improved boundary conditions • GFS-GOCART, HYSPLIT • Spatially & Temporally varying Lateral Boundaries (currently static) • Reduced gas phase chemistry (eg: RAQMS, GOloff & Stockwell, 2002)

  29. Future Work: Inline Chemistry (WRF-NMM-Chem) Youhua Tang & Georg Grell 2-D advection test with 15th layer wind Initial conditions formed with a cuboid between the 15th and 17th layers in the NMM domain center. Mass not conserved when only 2-d and 3-D advection used

  30. Future Work:Global Aerosol Forecasting & Data Assimilation(Sarah Lu, H-C Huang, Mian Chin…) NCEP CFS – GOCART Interactive Chemistry

  31. BACKUPS

  32. Exp 8h Max Regional PerformanceAugust 2, 2007 PIT CIN LOU NASH CHAR ATL Good forecasts for moderate event in PIT, DC, PHL, S. CT , Charlotte, Louisville, Cincinnati (clear skies)

  33. Regional Performance, Max 8-h O3Bias Reduced in 2007 Bias, 2007 Bias, 2006 • 2006 • High bias, up to +25 ppb • Underprediction NW coast • Underprediction SW coast • 2007 • Bias reduced • Good forecast for NW coast • Underprediction SWC (LA basin)

  34. Daily 8h Max Ozone BiasesExperimental (5X) run: All Sub-region biases Summer 2007 • 5X : • Under-prediction in California • Over-prediction in NW coast (for mod O3) • SW coast biases similar for both Summers

  35. Daily 8h Max Ozone Skill Scores2007 Operational (3X) vs Experimental (5X) POD=H/F FAR=1-H/F Operational: Better performance for high thresholds (8 hr standard >85 ppb) Experimental: Better performance at low/moderate ranges, worse over West

  36. PBL Height VerificationJuly 2007 (00Z, 5 PM PDT) Ri marine pbl estimates may be too low

  37. Acknowledgements • NOAA/OAR • Rohit Mathur – ASMD AQ team leader • Daiwen Kang – CMAQ verification, PM testing • Shaocai Yu – CMAQ diagnostic studies • Hsin-Mu Lin – PREMAQ development • Jon Pleim – CMAQ met processing development • J. Young, David Wong – Code optimization • George Pouliot, Daniel Tong – Emissions processing

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