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  1. Home
  2. Community Multiscale Air Quality Modeling System (CMAQ)
  3. Download CMAQ

Access CMAQ Source Code

CMAQ is a suite of Fortran 90 programs that work in concert to estimate ozone, PM, toxic compounds, and deposition throughout the troposphere.  The model requires significant computational resources to run and therefore requires a multi-processor computer running Linux.   CMAQ users should be comfortable with Linux scripting conventions and have some familiarity with the Fortran programming language. Users should also have some familiarity with atmospheric structure, and the physical and chemical processes that occur in the atmosphere.  

The CMAQ source code is currently housed on GitHub. GitHub is a web-based code repository hosting service. It allows for easier code maintenance and distribution. You can download model code from the command line or from your browser.  Users are also encouraged to create an account through the Community Modeling and Analysis System (CMAS) Center to take advantage of the training, conferences and software support provided by the center.   Visit the CMAS Center website to create a user account. 

Command Line Download for CMAQ Base Model from GitHub

CMAQ versions 4.7.1 through 5.5 are available from EPA's CMAQ GitHub Site.  CMAQv5.5 is the current main CMAQ release.  To download the CMAQ source code and scripts from the command line follow the following example template:

git clone -b [MODEL] https://github.com/USEPA/CMAQ.git [MODEL]

To download the latest version of CMAQ, [MODEL] should be replaced with main.  All other versions are specified by the version number, e.g., replacing [MODEL] with 5.4 will download CMAQv5.4.

Note that CMAQ-ISAM is included in the base model beginning with CMAQv5.3, WRF-CMAQ is included in the base model beginning with CMAQv5.3.3, and CMAQ-DDM-3D is included in the base model beginning with CMAQv5.4.  More information on CMAQ-ISAM, CMAQ-DDM, and WRF-CMAQ is provided on the CMAQ Models  page.

See the How to Cite CMAQ page for DOI's for each model version.

Getting Started with CMAQ

  • Check out the step-by-step tutorials for directions on how to prepare your Linux system for installing and running CMAQ.  A complete description of the CMAQ system is provided in the CMAQ User's Guide on GitHub.  Links to available tutorials, the User's Guide, and other scientific documentation are provided on the CMAQ Documentation page.  
  • Input and output data for the CMAQv5.5 benchmark can be used to test the build of the base model, WRF-CMAQ, CMAQ-ISAM and CMAQ-DDM-3D.  Directions on how to download the data can be found on the Model Inputs and Test Case Data page. 
  • Technical support and questions about this release should be directed to Help Desk at CMAS. 

Community Multiscale Air Quality Modeling System (CMAQ)

  • Learn About CMAQ
    • CMAQ's Purpose
    • CMAQ 25th Anniversary
    • Overview of Science Processes
    • Browse CMAQ Applications
  • CMAQ Models
    • CMAQ-ISAM
    • CMAQ-DDM-3D
    • WRF-CMAQ
    • MPAS-CMAQ
  • Download CMAQ
    • Model Source Code
    • Documentation
    • Resources/Utilities for Model Users
  • CMAQ Research
    • Research Highlights
    • CRACMM
    • How to Cite CMAQ
    • Publications and Peer Review
  • CMAQ Community
    • CMAQ User Community
    • Opportunities for Collaboration
    • CMAQ Webinars
    • CMAQ Community Survey Results
  • Download Data
    • Download CMAQ data
    • Test Cases
    • EPA'S Air Quality Time Series (EQUATES) Project
  • About Us
  • Frequent Questions
Contact Us about the Community Multiscale Air Quality Modeling System
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on October 2, 2024
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