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Base 2011b CAMx and CMAQ Modeling Results


The Western Air Quality Study (WAQS) performed photochemical grid modeling for the year 2011 using the Comprehensive Air Quality Model with Extensions (CAMx) version 6.10 and the Community Multiscale Air Quality (CMAQ) model version 5.0.2. The WAQS 2011 base year simulation version b (WAQS_Base11b) was derived from the Three State Air Quality Study 2011 version A modeling platform (3SAQS_Base11a). The WAQS_2011b simulation includes series of updates and improvements to the input data and model configurations used for the 3SAQS_Base11a.

The WAQS_Base11b base case model performance was evaluated against concurrent measured ambient concentrations using graphical displays of model performance and statistical model performance measures. The CAMx and CMAQ performance were compared against established model performance goals and criteria, following the procedures recommended in EPA’s photochemical modeling guidance documents. The evaluation included sub-regional evaluations for Colorado, Utah, Wyoming, and New Mexico; and evaluations by month and season.

Modeling Performance Evaluation Report (Jan 2016)


Model performance evaluation plots for simulation Base11b are available from the Intermountain West Data Warehouse (IWDW)

Monitoring Sites in the 4-km domain

WAQS_Base11b Change Log

Summary of the changes in the WAQS_Base11b relative to 3SAQS_Base11a.


  • WRF Winter Configuration: January - March


  • NEI2011v2 modeling platform inventories used for all emissions categories other than for the 3SAQS O&G basins
  • O&G
    • NEI2011v2 Inventories for non-3SAQS O&G data
    • 3SAQS 2nd phase O&G inventories
    • Reconciliation between NEI2011v2 and 3SAQS 2nd Phase inventories
  • Fires
    • PMDETAIL 2011v2
  • Residential Wood Combustion
    • 50% reduction in all RWC species from the NEI2011v2

Chemistry-Transport Model

  • Modeling
    • CMAQ run for 36/12/4-km modeling domains rather than only the 4-km domain.
  • Boundary Conditions
    • NOAA/NCAR MOZART with dust and seasalt set to 0.0
  • Snow cover/albedo fix for winter O3


  • Oil and gas emissions for the Williston Basin in Montana and the Great Plains Basin in the Dakotas are missing from simulation Base11b. The IWDW generated Base11b_v2 CAMx and CMAQ-ready emissions that include the missing Montana/Dakotas oil and gas sources. While these emissions data have been QA'd, they have not been run through an air quality model by the IWDW.