CMAQ 25th Anniversary

CMAQ 25: Celebrating 25 years of modeling excellence

In 2023 we celebrate the 25th anniversary of the first CMAQ public release on June 30, 1998 by looking back at major milestones in CMAQ science with #CMAQ25th.  We'll be reaching out to the CMAQ community for stories and reflections about the evolution of CMAQ and numerical air quality modeling in general.  If you have a story or a comment to share please reach out to us through the 'Contact Us' link on this page.  Happy Anniversary CMAQ!

Environmental Managers Magazine Commemorates 25th Anniversary of CMAQ

The January 2024 issue of the Air & Waste Management Association's EM Magazine for environmental managers commemorates the 25th anniversary of the initial release of CMAQ. The issue of EM highlights “the value of modeling communities to strengthen atmospheric science” using the lens of the CMAQ community. 

EPA's Science Matters Newsletter Series on CMAQ's 25th Anniversary

Celebrating CMAQ's 25th Anniversary with 25 Posts on X in 2023

#DYK 2023 marks the 25th anniversary of @EPA’sour Community Multiscale Air Quality Model (CMAQ) supporting air quality management under the Clean Air Act. Throughout 2023, we will highlight major milestones in CMAQ science. #SoundScience4CleanAir #CMAQ25th
Modular, extensible, “one-atmosphere”: a 1996 article describes how CMAQ was designed with these principles to guide scientific & regulatory assessments of multiple air pollutants in the same modeling system. https://doi.org/10.1016/1352-2310(95)00174-3 #CMAQ25th
In 2006, #EPAers published the technical details of how CMAQ is a scientific computer model of atmospheric chemistry and physics that comprehensively represents the most important physical and chemical processes affecting #aAir qQuality, including interactions with weather and emissions. The science in CMAQ is continually updated with new knowledge. #SoundScience4CleanAir #CMAQ25th
Analyzing multi-decadal changes in ambient fine particulate matter concentrations (PM2.5) estimated by #CMAQ and mortality data, a 2020 study demonstrated that reducing manmade PM2.5 contributed to lower cardiovascular mortality.
#CMAQ was used to identify how a new class of particle pollution resulting from manmade and natural pollutant sources contributes to increased cardiorespiratory disease mortality across the U.S. https://nature.com/articles/s41467-021-27484-1 #CMAQ25th #HeartMonth #OurHearts
Screen shot of a tweet highlighting the EQUATES dataset, which also was also supported with a publication that appeared just a week prior to this tweet. Foley et al., Data in Brief, 2023
Image of tweet celebrating the 25th anniversary of CMAQ #CMAQ25th
EPA scientists used CMAQ to show trends from industrialization and emissions controls in the Northern Hemisphere 1995-2010. As emissions reductions across the US decreased particle pollution, more sunlight could reach the ground. https://doi.org/10.5194/acp-15-12193-2015
The initial release of the National Air Quality Forecasting System included technical contributions and evaluation from current CMAQ Team members Jon Pleim, George Pouliot, David Wong Rohit Mathur, Daiwen Kang, and Tanya Spero. See this paper: https://doi.org/10.1175/WAF855.1
Recognizes the role of emissions from natural sources. Figure is from EM article published in October 2021 by Daiwen Kang, Jeff Willison, Golam Sarwar, Mike Madden, Christian Hogrefe, Rohit Mathur, Brett Gantt, and Alfonso Saiz-Lopez. https://www.awma.org/content.asp?admin=Y&contentid=731
CMAQ was used in the inaugural Air Quality chapter in the 2018 @usgcrp 4th National Climate Assessment. Using climate change scenarios refined by EPA downscaling, CMAQ showed how ozone levels may change across the US over the 21st century. https://nca2018.globalchange.gov/chapter/13/
This tweet highlights the MPAS-CMAQ global coupled modeling system in the Advanced Air Quality Modeling System (AAQMS).
Picture of CMAQ logo to celebrate the 25th anniversary of the first CMAQ release,
Picture of US EPA CMAQ Team members
This tweet highlights the use of CMAQ to simulate air pollution in urban areas, such as NYC, which have complex meteorology, emissions, and atmospheric chemistry. This tweet features a figure from Torres-Vazquez et al. (https://doi.org/10.1029/2021JD035890)
This tweet highlights the scientific advances put forth by the two-way coupling of CMAQ with meteorology, in this case with the WRF model. The tweet highlights the seminal article by Wong et al., GMD, 2012 (https://doi.org/10.5194/gmd-5-299-2012)
Image is Figure 1 from an article in Environmental Fluid Mechanics by Robin Dennis and coauthors, published in 2010 (https://doi.org/10.1007/s10652-009-9163-2). The image shows how modeled concentrations and atmospheric deposition are evaluated in four broad categories (operational, dynamic, diagnostic, and probabilistic evaluation) to bolster confidence in modeled solutions and to identify areas for model improvement.
Image is Figure 3 from an article in Geoscientific Model Development by Qian Shu and coauthors, published in 2023 (https://doi.org/10.5194/gmd-16-2303-2023). Image shows the total and attributed atmospheric concentrations ozone near the ground to twelve emissions sectors as a function of hour of the day and apportionment technique.
Image is from an article in Environmental Science & Technology by Emma D’Ambro and coauthors, published in 2021 (https://doi.org/10.1021/acs.est.0c06580). Image shows that while high concentrations of emitted PFAS are deposited close to the source facility, about 95% of the atmospheric emissions of PFAS are transported and deposited more than 150 kilometers from the source.
Figure 7 from an article by Havala Pye and coauthors, “Linking gas, particulate, and toxic endpoints to air emissions in the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM),” published in Atmospheric Chemistry & Physics in 2023 (https://doi.org/10.5194/acp-23-5043-2023). Image shows properties of various pollutant species modeled by CRACMM, which is implemented within the Community Multiscale Air Quality (CMAQ) modeling system.
Attendees gathered at the 21st Annual CMAS Conference (October 2022) hosted by the CMAS Center at University of North Carolina at Chapel Hill. Image courtesy of the CMAS Center.
Image shows graphic identifier for the Air Quality Model Evaluation International Initiative (AQMEII), a decade-long evaluation study among researchers in U.S., Canada, and Europe. Image shows on the left the globe rotated to focus on North America juxtaposed with an image on the right of the globe rotated to focus on Europe. Arrows connecting the two globe images depict a feedback loop, and the project name, AQMEII, is in the center of the image. Image is in shades of blue with white.
The tweet highlights the transparency and accessibility of the CMAQ system via peer review and open source on GitHub.
Figure 12a from an article by Christian Hogrefe and coauthors, entitled, “An analysis of CMAQ gas-phase dry deposition over North America through grid-scale and land-use-specific diagnostics in the context of AQMEII4,” published in Atmospheric Chemistry & Physics in 2023 (https://doi.org/10.5194/acp-23-8119-2023). The image depicts annual total ozone dry deposition fluxes over North America simulated by two configurations of CMAQ for different land uses and dry deposition pathways.
Photograph of twilight ice fog encompassing the valleys of Alaska. Photo credit: Geophysical Institute, University of Alaska Fairbanks.

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Last updated on January 3, 2024