CMAQ 5.4 Release (October 2022)

Announcing the release of CMAQ version 5.4 (October 14, 2022)


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 5.4.

What’s new in CMAQv5.4?

  • Updated chemistry for ozone (O3) and particulate matter (PM) formation from global-to-local scales

  • Introduction of the Community Regional Atmospheric Chemistry Multiphase Model (CRACMM)

  • Biogenic emissions algorithm options have been expanded

  • Revised algorithms for modeling the dry deposition of particles from the atmosphere (M3DRY and STAGE updates)

  • Streamlined building of the coupled WRF-CMAQ system compatible with WRFv4.4+ and an important bugfix for WRF-CMAQ users who previously used the CMAQv5.3 series

  • Improved efficiency, accuracy, and user experience for CMAQ instrumented model extensions CMAQ-DDM-3D and CMAQ-ISAM

  • Expansion of emissions diagnostic output features

  • Introduction of a domain-wide Budget Reporting tool

  • Online integration of common pollutant post-processing tasks (i.e. output total PM2.5 mass and more directly!)

  • Community Contribution: Incorporation of the Two-Dimensional Volatility Bases Set (2D-VBS) chemical mechanism

  • New versions of the Atmospheric Model and Evaluation Tool (AMETv1.5) and the Visual Environment for Rich Data Interpretation (VERDIv2.1.4)

See the full list of CMAQv5.4 updates on our new CMAQ Wiki page: CMAQv5.4 Series FAQ · USEPA/CMAQ Wiki · GitHub.

Download the source code and scripts, and access all documentation for this release from the USEPA GitHub repository:

Two-day test data for CMAQ version 5.4 are available from the CMAS Data Warehouse and the EPA anonymous ftp server: CMAQ Inputs and Test Case Data | US EPA

Documentation for this release includes the following:

  • Frequently asked questions for upgrading to version 5.4

  • New and updated step-by-step tutorials (14 total) for different features and functions of the software including tutorials for running base CMAQ, WRF-CMAQ, CMAQ-ISAM and CMAQ-DDM-3D and using the new chemical mechanism CRACMM

  • Release notes providing details on major changes and new features

  • Tables of model species and chemical reactions in each chemical mechanism available in v5.4

CMAQ version 5.4 documentation direct link on GitHub:

Please report any bugs or problems with this release to the CMAS User Forum:

Additional user support, including training courses and other CMAS-supported software products is available through the CMAS Center website:


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