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CMAQ 4.6 Release Notes

The Model Development Team is pleased to announce that CMAQ version 4.5.1 has been delivered to CMAS for public release. You can access the model from the CMAS. Exit EPA Disclaimer.

Below is a list of updates since the version 4.5.1 release:

  1. Aerosols
    • Updated ISORROPIA to v1.7 (includes correction in activity coefficients for temperatures other than 298 K)
    • Revised to use T, RH-dependent gamma (heterogeneous N2O5reaction probability) from Evans & Jacob (2005)
    • Upper limit set for the relative humidity input to ISORROPIA (95%)
    • Updated parameters written to the aerosol diagnostic file
  2. Chemistry
    • Carbon Bond (CB05) mechanism and associated EBI solver
    • Include the gas-phase reactions involving N2O5 and H2O
    • Removed obsolete mechanism combinations (e.g. gas+aerosols w/oaqueous)
  3. PBL modeling
    • New ACM2: combined non-local and local closure scheme
  4. Plume-in-Grid
    • Capability for AE4 mechanisms
  5. Mercury
    • Capability for CB05, AE4 mechanism (see MERCURY_NOTES)
  6. Hazardous Air Pollutants
    • Increased number of gas-phase HAPs; added several toxic metals and diesel components in particulate material (adapted for CB05 and SAPRC99 chemical mechanisms, and AE4)
  7. Carbon Apportionment
    • Added capability for the CB05 mechanism
  8. Sulfate Tracking
    • Added capability for: CB05, AE4 mechanisms; and "cloud_acm" module
  9. CGRID Restart File
    • Added a CGRID restart file (used to initialize next day's simulation; permits flexibility in the CONC file; can write subset of species and layers for the CONC file)
  10. Parallel I/O library
    • Various updates (new version required for CMAQv4.6 compilation)
  11. Other
    • Added a utility program to convert MCIP data into HYSPLIT format

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