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CMAQ

CMAQ is an active open-source development project of the U.S. EPA that consists of a suite of programs for conducting air quality model simulations.

CMAQ is supported and distributed by the CMAS Center. CMAQ combines current knowledge in atmospheric science and air quality modeling with multi-processor computing techniques in an open-source framework to deliver fast, technically sound estimates of ozone, particulates, toxics, and acid deposition.

Visit the EPA's CMAQ Site


What's New in Version 5.5

CMAQ Fact Sheet

The U.S. EPA Office of Research and Development and the Community Modeling and Analysis System Center are pleased to announce the release of CMAQ version 5.5.

What's new in CMAQv5.5?

  • Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM) version 2 including updated formaldehyde chemistry impacting ozone and secondary organic aerosol formation
  • New support for running pre-configured global CMAQ simulations coupled with meteorology from the Model for Prediction Across Scales:- Atmosphere (MPAS-A)
  • Expanded capabilities of the Integrated Source Apportionment Method (ISAM) to quantify source contributions to total secondary organic aerosol (SOA) and individual species
  • Updates to ISAM source attribution estimates, mainly impacting coarse particles and secondary organic aerosols formed through cloud processes
  • Updates to the Decoupled Direct Method (DDM) to improve second order ozone sensitivities
  • Updated chemistry to properly capture photolysis effects from sub-grid clouds
  • Revised algorithms for modeling dry deposition (M3DRY and STAGE updates)
  • Improved accuracy and error checking for BDSNP soil NO in the MEGAN biogenic emissions algorithm
  • MCIP (meteorology pre-preprocessor) updates to grid origin definition for fine scale Lambert Conformal Grids (i.e., < 4km )
  • Updates to Sulfur Tracking Model (STM) to properly attribute sulfate from gas phase chemistry
  • Updates to the Explicit and Lumped Model Output (ELMO) synthesizer to fix erroneous output for several PM aggregates including PMF_OC, PMF_NCOM, TNO3
  • New shp2cmaq python tool to convert GIS shapefiles into gridded netCDF mask files that can be used for defining regions and region families with DESID and using geographic source regions when running CMAQ-ISAM
  • Simplified workflows for easier CMAQ installation

    • Important note for WRF-CMAQ users

  • Coupled WRF-CMAQv5.5 (Wong et al., 2010) is compatible with WRF versions 4.4 to 4.5.1. EPA's testing of WRF-CMAQ has included chemical mechanisms CB6r5 and CRACMMv1 with the M3DRY dry deposition scheme. Other model options can be used with the WRF-CMAQ model but will have limited user support for issues that are encountered.

    • See the full list of CMAQv5.5 updates on the EPA's new CMAQ Wiki page: CMAQ Wiki Page.

    Resources




    Latest Version: CMAQ version 5.5

    DOWNLOAD | DOCUMENTATION


    CMAQ In-person Training

    No classes currently scheduled.

    CMAQ Online Training

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    Support

    Online Resources

    Previous Documentation

    System Requirements

    O/S Linux
    Processor 64-bit x86
    Memory >1 Gb RAM
    Disk Space > 80 Gb
    Software VERDI, I/O API, netCDF,MPI, IDV, Portland Group Fortran, Intel Fortran

    Community Modeling and Analysis System (CMAS)

    General inquiries about the CMAS Center and questions about the web site should be directed to cmas@unc.edu

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