Community Multiscale Air Quality Model US EPA CMAQ Website: (https://www.epa.gov/cmaq).
CMAQ is an active open-source development project of the U.S. EPA's Office of Research and Development that consists of a suite of programs for conducting air quality model simulations. CMAQ is supported by the CMAS Center: (http://www.cmascenter.org).
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.
CMAQv5.3.2 includes significant updates to the CMAQ Integrated Source Apportionment Method (ISAM) and multiple minor fixes to address issues identified in CMAQv5.3.1. The new CMAQ-ISAM version includes substantial updates to the gas-phase chemistry apportionment algorithms that improves both physical and numerical aspects of the method. Users of ISAM are strongly encouraged to update to CMAQv5.3.2.
- CMAQv5.3.2 Release Notes
- Frequently asked questions for upgrading to the latest CMAQ version - Updated for v5.3.2 release.
- Tutorials for setting up and running CMAQ - New tutorials on WRF-CMAQ, ISAM, and modifying a chemical mechanism.
- CMAQv5.3.2 Known Issues - Updated after the v5.3.2 release to alert users of issues that will be addressed with the next release.
- Simplified emissions scaling
- Improved representation of natural aerosols
- Expanded capability for ecological applications
- Stream-lined CMAQ-ISAM and CMAQ-STM
- Updates to pre-processors including ICON, BCON and MCIP
- Enhanced scientific complexity with faster run times
- Fully revised User's Guide and tutorials
- Additional updates are documented in the Release Notes
This CMAQ Git archive is organized with each official public release stored as a branch on the main USEPA/CMAQ repository. The most recently released version of the the model will always be on the branch called 'master'. To clone code from the CMAQ Git archive, specify the branch (i.e. version number) and issue the following command from within a working directory on your server:
git clone -b master https://github.com/USEPA/CMAQ.git CMAQ_REPO
Source code and scripts are organized as follows:
- CCTM (CMAQ Chemical Transport Model): code and scripts for running the 3D-CTM at the heart of CMAQ.
- DOCS: Release notes for the release version of CMAQ, CMAQ User's Guide, developers guidance, short tutorials and known issues.
- PREP: Data preprocessing tools for important input files like initial and boundary conditions, meteorology, etc.
- POST: Data postprocessing tools for aggregating and evaluating CMAQ output products (e.g. Combine, Site-Compare, etc)
- UTIL: Utilities for generating code and using CMAQ (e.g. chemical mechanism generation)
Release Notes and code documentation are included within this repository (they are version-controlled along with the code itself).
- CMAQ User's Guide
- Release Notes
- Known Issues
- Tutorials
- Developers' Guide
- FAQ for upgrading to the latest CMAQ version
Benchmark/tutorial data for each CMAQ release version are available from the CMAS Data Warehouse. The input and output files are stored on Google Drive with metadata organized through Dataverse. CMAQv5.3.2 comes with new input and output benchmark data for July 1-2, 2016 over the Southeast US (links provided below). The input datasets for these two days are identical to those released with v5.3.1 except for the addition of a grid mask file for the United States: GRIDMASK_STATES_12SE1.nc. As a result, there is no need for users who have already downloaded the v5.3.1 Southeast benchmark input data to download the v5.3.2 files unless they need the grid mask file for running the new ISAM test case or to test out regional emissions scaling with DESID. The Southeast benchmark output data for v5.3.2 is slightly different from what was released with v5.3 as described in the CMAQv5.3.2 Rlease Notes FAQ.
| CMAQ Version | Data Type | Domain | Simulation Dates | Dataverse DOI |
|---|---|---|---|---|
| v5.3 | Input | CONUS | Jan 1 - Dec 31, 2016 | https://doi.org/10.15139/S3/MHNUNE |
| v5.3, v5.3.1, v5.3.2 | Input | Southeast US | July 1 - 14, 2016 | https://doi.org/10.15139/S3/IQVABD |
| v5.3, v5.3.1 | Output | Southeast US | July 1 - 14, 2016 | https://doi.org/10.15139/S3/PDE4SS |
| v5.3.2 | Output | Southeast US | July 1 - 2, 2016 | https://doi.org/10.15139/S3/PDE4SS |
The benchmark data is also available form the US EPA annoymous ftp server: https://gaftp.epa.gov/exposure/CMAQ/V5_3_2/Benchmark/WRFv4.1.1-CMAQv5.3.2/
The followoing release versions of CMAQ are currently available on GitHub. DOI values from Zenodo can be used when referencing a specific version.
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v5.3.1 (December 2019) - doi:10.5281/zenodo.3585898 | Users Guide | Known Issues | Release Notes | Tutorials
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v5.3 (August 2019) - doi:10.5281/zenodo.1212601 | Users Guide | Known Issues | Release Notes | Tutorials
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v5.2.1 (March 2018) - doi:10.5281/zenodo.1212601 | Users Guide | Known Issues | Release Notes | Tutorials
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v5.2 (June 2017) - doi:10.5281/zenodo.1167892 | Users Guide | Known Issues | Release Notes | Tutorials
- Frequent CMAQ Questions are available on our website.
- The CMAS User Forum is available for users and developers to discuss issues related to using the CMAQ system. Please read and follow these steps prior to submitting new questions to the User Forum.
The United States Environmental Protection Agency (EPA) GitHub project code is provided on an "as is" basis and the user assumes responsibility for its use. EPA has relinquished control of the information and no longer has responsibility to protect the integrity , confidentiality, or availability of the information. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply their endorsement, recommendation or favoring by EPA. The EPA seal and logo shall not be used in any manner to imply endorsement of any commercial product or activity by EPA or the United States Government.
