You are here:
Updates in and evaluation of the Community Multiscale Air Quality (CMAQ) modeling system version 5.4
Citation:
Appel, Keith, C. Hogrefe, K. Foley, R. Gilliam, D. Kang, G. Pouliot, B. Murphy, H. Pye, B. Place, J. Pleim, J. Bash, G. Sarwar, S. Napelenok, Cheung Wong, R. Mathur, F. Sidi, C. Nolte, J. Willison, K. Fahey, Bill Hutzell, E. D'Ambro, T. Spero, AND D. Schwede. Updates in and evaluation of the Community Multiscale Air Quality (CMAQ) modeling system version 5.4. 103rd Annual American Meteorological Society Meeting, Denver, CO, January 08 - 12, 2023.
Impact/Purpose:
The Community Multiscale Air Quality (CMAQ) model is a state-of-the-science air quality model that simulates the emission, transport, and fate of numerous air pollutants, including ozone and particulate matter. In the fall of 2022, the CMAQ version 5.4 will be released.
Description:
The Community Multiscale Air Quality (CMAQ) model is a state-of-the-science air quality model that simulates the emission, transport, and fate of numerous air pollutants, including ozone and particulate matter. The Atmospheric and Environmental Systems Modeling Division of the U.S. Environmental Protection Agency develops the CMAQ model and periodically releases new versions of the model that include improvements to the science algorithms and options as well as new features and bug fixes. In the fall of 2022, the CMAQ version 5.4 will be released. This new version of CMAQ contains important updates from the current CMAQv5.3.3 modeling system, along with updates to several instrumented versions of the model (i.e., Decoupled Direct Method in 3-D and Integrated Source Apportionment Method). Examples of important science updates in the model include version 5 of the Carbon Bond 6 (CB6r5) chemical mechanism, updated dimethyl sulfide (DMS) and marine halogen chemistry, updated M3Dry and STAGE deposition models, and implementation of the Model of Emissions of Gases and Aerosols from Nature (MEGAN) biogenic emissions model. Another major update in CMAQv5.4 is the availability of version 1.0 of the new Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM) chemical mechanism. Version 5.4 also includes new tools and diagnostics, including the new Explicit and Lumped CMAQ Model Output (ELMO) module to easily generate lumped chemical species (e.g., PM2.5), a new budget tool to quantify process contributions to domain-wide pollutant totals to help characterize sources and loss mechanisms of mass, and updates to the existing Detailed Emissions Scaling, Isolation, and Diagnostics (DESID) module. Several annual CMAQv5.4 simulations will be performed using various configuration options available in the model to assess the impact of these specific updates. The results from these and other simulations will be presented, along with an operational evaluation of the performance of the CMAQv5.4 versus the previous version of the modeling system and against available surface and upper-air air quality measurements.
