Document ID: EPA-HQ-OAR-2011-0135-0102
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2013-04-15T04:00Z

RELEASE_NOTES for CMAQv4.7 - 30 September 2008

The changes and new features of this release are:

1) Aerosols
      - SOA Model Enhancements
        + Updates: isoprene SOA, sesquiterpene SOA, polymerization, acid-
          catalyzed SOA, NOx-dependent SOA yields, and enthalpy of 
          vaporization
        + In-cloud SOA formation pathways (glyoxal, methylglyoxal)
        + Changes in gas-phase chemistry mechanism, emissions speciation, 
          and biogenic emmissions model, to represent SOA precursors
      - Coarse PM
        + Semi-volatile inorganic components (NO3-, Cl-, and NH4+) can 
          condense and evaporate from the coarse mode, via dynamic mass 
          transfer
        + Nonvolatile sulfate can condense on the coarse mode
        + Variable standard deviation of coarse mode size distribution
        + Emissions of sea salt from the surf zone
      - Heterogeneous reaction probability 
        + Re-derived parameterization based on Davis et al. (2008)

2) Chemistry

      - HONO enhancements
        + Heterogeneous reaction on aerosol and ground surfaces
        + Emissions from mobile sources 
      - Photolysis Options (beta versions)
        + In-line photolysis rate module, with aerosol feedback
        + Photolysis rates adjusted using satellite-derived cloud
          information (currently table-approach only)
      - Aqueous Chemistry
        + Added two organic oxidation reactions (glyoxal, methylglyoxal)
        + Updates to Henry's Law constants based on literature review
      - Base CB05 mechanism with Cl2 chemistry
      - Multi-pollutant Capability
      	+ Include HAPs and Hg in single modeling platform

3) In-line options
      - Dry Deposition
        + Moved calculation into CCTM
      - Emissions
        + Integrated BEIS into CCTM
        + Incorporated Plume-rise into CCTM
      - Bi-directional NH3 and Hg surface flux
        + for NH3, fertilizer emissions will be applied through the flux
          model (under development)

4) Emissions
      - Biogenic emissions:  added sesquiterpene emissions
      - Sea-salt emissions
        + Updated flux parameterizations & surf zone emissions
        + Used spatial allocator to produce ocean file
      - Speciation changes for HONO and benzene

5) Clouds
      - Convective cloud model
        + Revised to reduce layer configuration differences
        + Changed the integration timestep
      - Resolved cloud model
        + Correction in precipitation flux calculation

6) Diagnostic Tools (will be released during FY09)
      - Direct Decoupled Method (DDM)
      - Primary carbon source apportionment model
      - Sulfate tracking model

7) Model options no longer supported:
      - Plume-in-grid
      - CB4 mechanisms
      - Aero3 module and AE3 mechanisms
      - RADM cloud module
      - Stand-alone mercury version of CMAQ (capability is included in
        the multipollutant version)