Air Quality Modeling Update

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Air Quality Modeling Update

• Draft Modeling Protocol
• Basics
• Ozone Episodes
• PM2.5 and PM10 Modeling

May 10, 2006
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Draft Modeling Protocol

• Received preliminary comments from CARB
• Release to STMPR for review
• May schedule meeting with EPA on meteorological
  modeling
• Finalize by next AQMP Advisory meeting

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Basics
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Ozone Episodes

• Meteorological Modeling Considerations gt Two
  peak receptor areas - Crestline standard
  transport - Santa Clarita secondary
  peak gt MM5 simulations characterize south-
  westerly flow well gt LA wind bifurcation
  zone is characterized but midday westerly
  winds restrict northerly transport
  cutting off full transport impact to Santa
  Clarita gt Southeasterly flow will impact Santa
  Clarita

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Sensitivity Analyses

• Enhanced inventory (VOC/NOx ratio 2)
• Force ozone production to test transport
• Parameters evaluated gt PBL Schemes gt
  Initialization (humidity) gt Land Use (urban
  characterization)

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Enhanced Weekday InventoryJuly 16,2005
Maximum Observed
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Peak Ozone Concentration for July Episode
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(No Transcript)
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Crestline July 16, 2005
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17 Source Area
Emissions Source Areas
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Santa Clarita July 16, 2005
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17 Source Area
Emissions Source Areas
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Status

• Testing objective and hybrid wind fields
• Updated emissions inventory gt Temperature
  corrected gt Old transportation data gt
  Higher concentrations of biogenic emissions
• Evaluating different episodes

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Ozone Episodes

• Aug 5-7 1997 (2003 AQMP)
• Seasonal July August 1997
• 2004 June 5-6 Aug 6-7
• 2005 May 21-22, July 16-18, Aug 27-28
• May consider additional dates per transport to
  other Basins

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Rank and Comparison to Design Value
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PM2.5 PM10

• Annual simulations PM2.5 and PM10
• Evaluated quarterly
• Speciated analysis
• Candidate PM2.5 episodes gt March gt
  October

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Boundary and Initial Conditions

• WRAP modeling simulations (conducted by C-CERT)
  to drive boundaries
• Interpolation to top boundary
• Quarterly averages - gases particulates
• Future year impacts - rollback or WRAP
  simulated boundary conditions - uncertain
  Asian transport

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Emissions

• Set pattern
• - Weekday - Saturday - Sunday
• Monthly temperature correction
• Monthly biogenic emissions
• Monthly ammonia

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Simulation Turn Around

• 8 workstations with 16 Xeon processors
• Upgraded the Itanium II processor
• Turn Around (including set and post processing)
  3-4 days per year simulation