The CMAQv5.5.0.3 update is intended for users who wish to adopt the most recent bugfixes or minor updates. Documentation and benchmark datasets are still based on v5.5. The next major CMAQ release will include these bugfixes along with new science updates, features, documentation, and benchmark data.

What's Changed

• Resolve merge conflict accidently commited to xc_qy_td_effect.F by @DWesl in #247
• Increase string size for DDM-3D control file by @sergeynk in #249
• 5.5plus doc updates by @jbrunto in #250
• enable parallel I/O for ELMO, AELMO, and lightning diagnostic files by @cgnolte in #252
• Diagnostic NH3 emissions from Agriculture and Biogenic sources by @jeff-willison in #253

New Contributors

• @DWesl made their first contribution in #247

Full Changelog: CMAQv5.5.0.2_13May2025...CMAQv5.5.0.3_11Jul2025

What's Changed

• 5.5 Documentation Updates by @jbrunto in #234
• Corrections to ISAM aerosol and cloud processing by @sergeynk in #238
• Update conversion factor for area-based denominator by @bnmurphy in #240
• Adds pcVOC and NOy species to ISAM species lists by @bnmurphy in #241
• Updated Post-Processing support files and code by @bnmurphy in #242
• Fix bugs in shp2cmaq by @gongkangjia in #245
• 5.5 Tutorial Updates from CMAS by @kmfoley in #246
• DDM3D Correction to ebi solvers by @sergeynk in #239

New Contributors

• @gongkangjia made their first contribution in #245

Full Changelog: CMAQv5.5.0.1_19Mar2025...CMAQv5.5.0.2_13May2025

The CMAQv5.5.0.1 update is intended for users who wish to adopt the most recent bugfixes. Documentation and benchmark datasets are still based on v5.5. The next major CMAQ release will include these bugfixes along with new science updates, features, documentation, and benchmark data.

What's Changed

• Fix bug preventing CMAQ from running using SAPRC mechanisms by @cgnolte in #226
• Corrected NLCD to BELD3 mapping for shrub/scrub and dwarf scrub by @chogrefe in #222
• CRACMM2 fixes for ISAM and post processing by @havalapye in #231

Documenation Updates

• Documentation Updates by @jbrunto in #229
• Documentation Updates by @jbrunto in #230
• Updated templates for Issues and PRs by @kmfoley in #225
• 5.5 Documentation Updates by @jbrunto in #235

Full Changelog: CMAQv5.5_2Oct2024...CMAQv5.5.0.1_19May2025

CMAQv5.5, the latest version of the Community Multiscale Air Quality modeling system (release date October 2, 2024), includes many new scientific and user-oriented features:

• Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM) version 2 including updated formaldehyde chemistry impacting ozone and secondary organic aerosol formation

• New support for running pre-configured global CMAQ simulations coupled with meteorology from the Model for Prediction Across Scales – Atmosphere (MPAS-A)

• Expanded capabilities of the Integrated Source Apportionment Method (ISAM) to quantify source contributions to total secondary organic aerosol (SOA) and individual species

• Updates to ISAM source attribution estimates, mainly impacting coarse particles and secondary organic aerosols formed through cloud processes

• Updates to the Decoupled Direct Method (DDM) to improve second order ozone sensitivities

• Updated chemistry to properly capture photolysis effects from sub-grid clouds

• Revised algorithms for modeling dry deposition (M3DRY and STAGE updates)

• Improved accuracy and error checking for BDSNP soil NO in the MEGAN biogenic emissions algorithm

• MCIP (meteorology pre-preprocessor) updates to grid origin definition for fine scale Lambert Conformal Grids (i.e., < 4km )

• Updates to Sulfur Tracking Model (STM) to properly attribute sulfate from gas phase chemistry

• Updates to the Explicit and Lumped Model Output (ELMO) synthesizer to fix erroneous output for several PM aggregates including PMF_OC, PMF_NCOM, TNO3

• New shp2cmaq python tool to convert GIS shapefiles into gridded netCDF mask files that can be used for defining regions and region families with DESID and using geographic source regions when running CMAQ-ISAM

• Simplified workflows for easier CMAQ installation

• See the full list of CMAQv5.5 updates on the CMAQ Wiki page. CMAQv5.5 Updates

The CMAQv5.4.0.5 update is intended for users who wish to adopt the most recent bugfixes. Documentation and benchmark datasets are still based on v5.4. The next major CMAQ release will include these bugfixes along with new science updates, features, documentation, and benchmark data.

What's Changed

• Minor fixes to ELMO output algorithms by @bnmurphy in #218

Full Changelog: CMAQv5.4.0.4_9April2024...CMAQv5.4.0.5_5Sept2024

The CMAQv5.4.0.4 update is intended for users who wish to adopt the most recent bugfixes. Documentation and benchmark datasets are still based on v5.4. The next major CMAQ release will include these bugfixes along with new science updates, features, documentation, and benchmark data.

What's Changed Since V5.4.0.3

• Fix functionality of RBSTATS when using ROS3 by @srosanka in #198
• Update config_cmaq.csh by @lizadams in #201
• Update DESID explanations in the emissions tutorial by @bnmurphy in #206
• Corrected molecular weight of HGIIGAS as 271.5 g/mol rather than 200.6. by @kmfoley in #208
• Add documentation updates from main (v5.4) branch to 5.4+ branch by @kmfoley in #209
• fix bug in calculation of PMF_OC by @cgnolte in #215

Full Changelog: CMAQv5.4_14Oct2022...CMAQv5.4.0.4_9April2024

CMAQv5.4.0.3

The CMAQv5.4.0.3 update is intended for users who wish to adopt the most recent bugfixes for CMAQ DDM-3D. Documentation and benchmark datasets are still based on v5.4. The next major CMAQ release will include these bugfixes along with new science updates, features, documentation, and benchmark data.

What's Changed

• Ddm3d fix 31may2023 by @sergeynk in #194

Full Changelog: CMAQv5.4.0.2_4May2023...CMAQv5.4.0.3_9June2023

CMAQv5.4.0.2 is a minor update to CMAQv5.4 that includes multiple bug fixes documented in PRs #186 and #189.

Documentation and benchmark datasets are based on v5.4. The CMAQv5.4.0.2 update is intended for users who wish to adopt the most recent bugfixes or minor updates that improve model stability and efficiency. The next major CMAQ release will include these bugfixes along with new science updates, features, documentation, and benchmark data.

CMAQv5.4.0.1 is a minor update to CMAQv5.4 that includes multiple bug fixes documented in PRs #180, #181, #182, #183.

Documentation and benchmark datasets are based on v5.4. The CMAQv5.4.0.1 update is intended for users who wish to adopt the most recent bugfixes or minor updates that improve model stability and efficiency. The next major CMAQ release will include these bugfixes along with new science updates, features, documentation, and benchmark data.

CMAQv5.4, the latest version of the Community Multiscale Air Quality modeling system (release date October 14 2022), includes many new scientific and use-oriented features:

• 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+
• 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
• See the full list of CMAQv5.4 updates on the CMAQ Wiki page: CMAQv5.4 Updates