OThree Chemistry MM5/CAMx Model Diagnostic and Sensitivity Analysis Results: Recent Diagnostics and PA Central California Ozone Study: Bi-Weekly Presentation 4 T. W. Tesche Dennis McNally Harvey Jeffries 23 December 2003

OThree Chemistry Recent Analyses & Results  Recent Reporting  Diagnostic Experiments—Round 2 (sent 15 Dec ’03)  Diagnostic Experiments—Round 3 (sent 18 Dec ’03)  Process Analysis Spreadsheets– (sent 22 Dec ’03)  Bi-Weekly Presentation Materials– (sent 22 Dec ’03)  Round 2 Diagnostic Analyses  Run Bnp3v3 (NOx emissions decreased, VOC’s increased by factor of 3)  Run B No Dry Deposition (dry deposition zeroed-out)  Round 3 Diagnostic Analyses  Application of Kv Patch = 1.0 m2/s (CMAQ default value)  Application of Kv Patch = 0.1 m2/s (CAMx default value)  Re-run of Base B with new CAMx (ver 4.03)  Re-run of VOC emissions scale-up run (Bn3) with new CAMx (ver 4.03)  Process Analysis Update (by Prof. Jeffries)  Overview of Method as Applied to SJV’  Recent Results and Implications

OThree Chemistry Findings of Round 2 Diagnostic Runs  Runs are diagnostic only; not intended to imply California inventories possess factor of 3 systematic errors across all categories.  Scalar increases (by factor of 3) in anthropogenic VOC and/or NOx inventories yield much greater ozone changes compared with MM5 sensitivity experiments.  Factor of 3 increase in NOx emissions substantially degrades model performance in the SJV and across the 4 km domain.  Factor of 3 increase in VOC emissions improves model performance statistically and graphically in the SJV; improvements across the 4 km domain are less.

OThree Chemistry Round 2 Findings (concluded)  Factor of 3 VOC & NOx increases do not yield significant model performance improvement  Factor of 3 increase in VOC and decrease in NOx systematically degrades model performance  Removal of dry deposition process systematically degrades model performance  So far, VOC x3 scale-up run (Bv3) appears to shed most light on potential causes of ozone underprediction bias in Sept ’00 episode;  Round 2 results invite Process Analysis focus on role of VOC emissions in producing ozone in the SJV.

OThree Chemistry Findings of Round 3 Diagnostic Runs Findings of Round 3 Diagnostic Runs  Application of Kv_Patch (minimum of 1.0 m2/s) yields:  Slight improvement (~ 0.4 ppb) in the accuracy of peak 1-hr ozone predictions over all monitoring stations in the SJV subdomain  Slight degradation in episode average mean normalized bias (increases by ~ 1.3 ppb)  Slight degradation in episode average mean normalized gross error (increases by ~0.7 ppb)  Slight degradation in model’s underprediction tendency (non-normalized bias increases from –18.6 ppb to –19.3 ppb, averaged across all SJV monitors for the Sept ’00 episode  Overall, no major change in model’s gross statistical response, except slight worsening of the existing ozone underprediction problem.

OThree Chemistry Round 3 Findings (concluded) Round 3 Findings (concluded)  Migration to the newest version of CAMx (ver 4.03) appears to have:  No significant impact on the model’s response to significant precursor emissions changes.  Slight impact on model response when tested with emissions change scenario (Base Bv3: VOC’s scaled up by factor of 3), suggesting that this response would hold for other types of emissions changes as well.  Overall, no major impact on CAMx sensitivity to precursor emissions changes in migrating to newer version of model.

OThree Chemistry Update on Process Analysis  Methodology  Use of CAMx (ver 4.03) Base B Simulation  Integrated Process Rate (IPR) Process Analysis Tools from UT/UNC Package installed in CAMx (ver 4.03)  Analysis Sub-Areas  Elk Grove, Parlier (downwind Fresno), Arvin (downwind Bakersfield)  Initial Results  Refer to PDF Files Transmitted 23 Dec ’03 before today’s call  Currently unexplained vertical mixing processes (related to PBL heights and diffusivities) appear to affect chemical processing, day and night.  Potential for systematic overestimation of low reactivity VOC emissions (PAR) in CCOS inventory compared with other cities in U.S?  Insufficient supply of radical species in model to promote significant ozone formation?

OThree Chemistry Process Analysis Focus Sub-Areas Elk Grove Arvin Parlier

OThree Chemistry Vertical Ozone Slice Plots At Arvin East-West Slice on 18 Sept ’00 at 1500 PST Base B

OThree Chemistry Example of Unusual Vertical Mixing Phenomena North-South Slice on 18 Sept ’00 at 1500 PST Base B

OThree Chemistry VOCs (Kmoles) in CCOS Domain on 29 Jul ’00 BAAQMD staff identified potential concerns w/ inventory speciation

OThree Chemistry VOCs (kmoles) in CCOS Domain on 29 Jul ’00 BAAQMD inventory speciation QA performed in late Aug ‘03

OThree Chemistry Anthro VOC Emissions At Arvin: Unexpectedly high fraction of low reactive emissions (PAR) in inventory

OThree Chemistry Anthro VOC Emissions In Houston Typically smaller fraction of low reactive emissions (PAR) in HGA inventory

OThree Chemistry Next Steps  Emerging Need for Coordinated Review of VOC speciation methods in current CCOS modeling inventory  By ARB, Alpine Geophysics inventory staffs.  MM5 Sensitivity Simulation(s)  Implementation of FDDA findings from NOAA and Bay Area Modeling Results;  Adaptation of NOAA Land Use and Related Parameter Specifications  CAMx Sensitivity Simulations  Across-the-Board Adjustment of VOC emissions speciation  Local metropolitan (Fresno, Bakersfield) VOC emissions sensitivity experiments (mass emissions rates, speciation assumptions)  Sensitivity to ICs/BCs/TCs (GEOS-CHEM boundary conditions)  Sensitivity to diurnal/spatial PBL height and diffusivity profile estimates

OThree Chemistry Next Steps (continued)  Consider Merits of Invoking Other Probing Tools and Corroborative Models  OSAT, DDM  MAPPER