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Motivation Model simulations for California have usually underestimated ozone concentrations aloft

Model Aloft Study Ola Persson, Jian-Wen Bao, Sara Michelson Jim Wilczak NOAA/ Environmental Technology Laboratory. Motivation Model simulations for California have usually underestimated ozone concentrations aloft CCOS IOP simulations have under-predicted surface ozone concentrations

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Motivation Model simulations for California have usually underestimated ozone concentrations aloft

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  1. Model Aloft StudyOla Persson, Jian-Wen Bao,Sara MichelsonJim WilczakNOAA/ Environmental Technology Laboratory

  2. Motivation • Model simulations for California have usually underestimated ozone concentrations aloft • CCOS IOP simulations have under-predicted surface ozone concentrations • Hypotheses • Improper IC and BC’s • Insufficient model resolution • Too strong winds in stagnant conditions • Too weak of mixing of PBL O3 to layers above • Too weak recirculation of upslope flow back over CV • Errors in characterization of chemistry • Emissions

  3. NOAA & STI Components • NOAA: O3 & meteorological fields • initial and boundary conditions • meteorological dependent O3 formation • mixing • transport • STI: all chemical species • initial and boundary conditions • chemical mechanism • emissions

  4. Planned Analysis (NOAA) • MM5-CAMx and Hybrid comparisons for July-August and September 2000 IOP’s (utilizing ozone aloft data as well as meteorological obs) • Produce new simulations with WRF-Chem model • Run additional simulations with improved MM5-CAMx model.

  5. CAMx Experiments • 'A60' MM5 without observational FDDA • 'A59' MM5 with observational FDDA • 'A53' meteorology from the CALMET/MM5 hybrid • The two MM5-CAMx simulations used 40ppbv lateral and top boundary conditions • Hybrid run used a truncated model to 5 km, with 70ppbv lateral and top boundary conditions

  6. Ozone sonde evaluationJuly-August IOP • Parlier (16 sondes) • Granite Bay (12 sondes)

  7. Parlier ozone sonde site

  8. Granite Bay ozone sonde site

  9. Parlier MM5 MM5- FDDA Hybrid Sonde

  10. Parlier Bias MM5 MM5-FDDA Hybrid

  11. Granite Bay MM5 MM5- FDDA Hybrid Sonde

  12. Granite Bay Bias MM5 MM5- FDDA Hybrid

  13. Parlier Model Sonde Bias Hybrid MM5-FDDA

  14. Granite Bay Hybrid MM5-FDDA

  15. Bias MM5 MM5-FDDA Hybrid Granite Bay Parlier

  16. RMS difference MM5 MM5-FDDA Hybrid Granite Bay Parlier

  17. Correlation Coefficient Cor Coef Cor Coef Parlier Granite Bay

  18. Biggest differences aloft among 3 models are due to larger O3 value used as lateral and top boundary conditionWhat is the most appropriate value for BC for ozone?

  19. Trinidad Head (NOAA/CMDL)

  20. Trinidad Head Summer 2000 11 soundings

  21. Median ozone profiles at all IONS sites, July 1 – August 15, 2004 Summer 2004 Ozone Sondes Owen Cooper, AL/NOAA

  22. Owen Cooper, AL/NOAA

  23. Owen Cooper, AL/NOAA

  24. Owen Cooper, AL/NOAA

  25. Asian Plume Qing Liang/UW

  26. Observed Chemical Composition of Asian Plumes Qing Liang/UW

  27. TH ozone sondes suggest that mean tropospheric lateral bc’s should be approximately 60 ppbv • Significant departures from 60 ppbv can occur due to tropopause folding events and due to asian plumes • Significant height variation exists in the mean TH profile, especially in lowest 2 km

  28. NWS Eta-CMAQ Boundary Conditions • CMAQ-Eta simulations for the summer of 2004 in New England over-predicted surface ozone by ~10 ppb. Mathur (2005) traced this bias to too high of ozone values for lateral and top boundary conditions. • Present CMAQ-Eta operational model uses O3 lateral and top boundaries from the GFS global model for heights > 6km, climatology below.

  29. Satellite Measurements of Chemical Species • O3 • CO • CH4 • CO2 • NO2 • HCHO • SO2 • AOD, etc. • AIRS • MODIS • SCIAMACHY • MOPITT • GOME, etc.

  30. Recommended areas of investigation – High bias at coastal sites and over land at night • Sensitivity tests to height-dependent O3 profile in initial state and at lateral inflow boundaries • Vertical resolution of CAMx near surface • Chemical deposition over water • Kz in stable conditions • Chemical processing in off-shore stratus(?)

  31. Recommended areas of investigation – Low bias at land sites during day • Sensitivity tests to larger O3 lateral and top boundary values (30-110 ppbv) • Higher vertical resolution chemistry model simulation to reduce mixing between PBL and aloft

  32. Next steps • Analyze day and night profile statistics separately at Parlier and Granite Bay • Compare 3 models with Trinidad Head O3 soundings • Compare 3 models with aircraft observations • Repeat analysis using MM5-CMAQ from Seasonal Modeling study • Add MM5-CAMx runs using hourly averaged model winds • Add WRF-Chem run using CARB emission inventory • Repeat all of analysis for September IOP

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