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CMAQ 4.5 Release Notes

The Model Development Team is pleased to announce that CMAQ version 4.5 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 4.4 release:

  1. Aerosols
    • Added sea salt (fine equilibrium; non-interactive coarse mode) -- aero4
    • Updated aerosol dry deposition algorithm
    • Updated mechanism include files to remove any aerosol species with zero concentrations for aero4
    • Updated ISORROPIA to v1.5 (25 Oct 2003) and fixed some discontinuities
    • Added diagnostic variables to calculate PM2.5 concentrations
    • Corrected bug in mode merging to reduce mode crossover
    • Modified SO4 used in ISORROPIA call
    • Corrected inconsistency in MINL2SG (aerodepv)
    • Corrected the EMSULF (H2SO4 emissions) unit conversion bug
  2. Chemistry
    • Added CB4/chlorine chemistry and associated EBI solver
    • Added CB4/air toxics and SAPRC99/air toxics chemistry and associated EBI solvers
    • Added degradation algorithm to the generalized solvers
    • Corrected treatment of convergence failures in EBI solvers
    • No longer support the RADM2 mechanism
  3. P-in-G
    • Improved calculation of plume centerline
    • Fixed bug in the aerosol species array subscripting
    • Corrected error in non-reactive species NH3 fluxes and dry deposition
  4. PBL modeling
    • Updated to use PURB (% urban) for setting minimum Kz
  5. Clouds
    • Added new sub-grid cloud mixing algorithm/module (based on ACM)
    • Added new cloud diagnostic variables
    • Corrected the interpolation times for resolved clouds (to time-step midpoint) and for subgrid clouds (to half hour)
  6. Advection
    • Added new mass continuity scheme
  7. Other
    • Added dynamic vertical layer allocation
    • Added primary carbon source apportionment capability
    • Added sulfate tracking capability


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