Air Resources Board California Environmental Protection Agency March 13, 2003Presentation to the Policy Committee1 Ozone SIP Modeling and Data Analysis: Part 3 Presented by Modeling Staff of ARB

March 13, 2003Presentation to the Policy Committee2 Contents  SIP Modeling Process  Meteorological Modeling  Air Quality Modeling  Current Schedule

March 13, 2003Presentation to the Policy Committee3 SIP Modeling Process  Multi-district modeling effort Regular meetings with Districts modeling and related issues emissions inventory QA/QC Active participation in the Bay Area MAC  Episodes considered July-August, 2000 (All) September 2000 (SJV) June 2000 (BA, Sac?) July 1999 (All) July 2002 (Sac?)

March 13, 2003Presentation to the Policy Committee4 CCAQS Modeling Domains

March 13, 2003Presentation to the Policy Committee5 SIP Modeling Process (Cont.)  Models considered Emissions EMS-95 with BEIGIS, EMFAC, and DTIM Meteorology MM5, RAMS, CALMET/MM5 Hybrid Air Quality SAQM, CAMx, CMAQ Model selection based on UCR findings BAAQMD proceeding with CAMx CMAQ may not be considered

March 13, 2003Presentation to the Policy Committee6 SIP Modeling Process (Cont.)  Chemical Mechanisms CB-IV – Efficient, old standard, no significant updates SAPRC – time-consuming, state-of-the-science, continual updates, recommended by the Reactivity Scientific Advisory Committee  Modeling Protocols SJV protocol being updated (SJVAPCD/ARB) BAAQMD protocol is draft final (ENVIRON) Sacramento protocol planned (SMAQMD/ARB/DRI)

March 13, 2003Presentation to the Policy Committee7 Meteorology Modeling: MM5

March 13, 2003Presentation to the Policy Committee8 Meteorology Model Performance  Issues Air temperature under-estimated Wind speed over-estimated Vertical mixing uncertain  Improvements Alternative synoptic-scale initialization Alternative boundary-layer schemes Different numbers and thickness of vertical layers Analysis and Observational FDDA

March 13, 2003Presentation to the Policy Committee9 Air Quality Modeling  Models currently used SAQM CAMx  Ozone episodes currently being modeled August, 1990 SARMAP episode July-August, 2000 CCOS episode  Meteorology used MM5 – ARB MM5 - NOAA CALMET/MM5 Hybrid

March 13, 2003Presentation to the Policy Committee10 Air Quality Movie

March 13, 2003Presentation to the Policy Committee11 Air Quality on July 31, 2000

March 13, 2003Presentation to the Policy Committee12 Air Quality on August 01, 2000

March 13, 2003Presentation to the Policy Committee13 Air Quality on August 02, 2000

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March 13, 2003Presentation to the Policy Committee17 Air Quality Model Performance Preliminary ARB modeling indicates:  Fair Ozone model performance downwind of SF Bay area  Ozone over-estimated downwind of urban Sacramento area  Ozone under-estimated downwind of urban Bakersfield area

March 13, 2003Presentation to the Policy Committee18 AQ Model Improvements  Investigative simulations  Initial and boundary conditions  Emissions  Meteorology

March 13, 2003Presentation to the Policy Committee19 Computer Resources  ~30x more resources needed compared to SARMAP (with CB-IV chemistry) Modeling domain is 3x larger Horizontal grid size is 9x smaller E.g. One episode day = 0.5 CPU days  ~90x more resources for SAPRC  Currently improving computer resources to meet the challenge