RELEASE_NOTES  9 July 2002

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  The major changes and new features of this release are:

  1) A new aerosols module, aero3, that includes:
     + improved treatment for Secondary Organic Aerosol formation by including
       semivolatile compounds that partition between gas and aerosol phases,
     + updated process for Sulfate nucleation,
     + heterogeneous conversion of N2O5 to Nitric Acid,
     + incorporate the ISORROPIA model for thermodynamics.

  2) Incorporate aerosol emissions in the vertical diffusion process.

  3) Change the order of the time splitting science processes:
        from chemistry -> clouds -> aerosols
          to clouds -> chemistry -> aerosols
     to provide a better linkage between gas-phase chemistry and aerosols.

  4) Add the Saprc99 gas-phase mechanism and all CMAQ variants.

  5) Add Modified Euler Backward Iterative (MEBI) solvers for all variants
     of CB4, SAPRC99, and the RADM2-Carter-4-Product-Isoprene mechanisms.

  6) Add a new vertical diffusion module, the Asymmetric Convective Model (ACM).

  7) Change to a dynamic allocation of the horizontal grid for the chemistry
     model (CCTM) and the initial and boundary concentrations pre-processors
     (ICON and BCON). This allows one executable to run any horizontal
     domain that CMAQ supports.

  8) In conjunction with (7), CCTM now can window from meteorology and
     emissions datasets, so that runs on many subdomains can be executed using
     one dataset that encompasses all those subdomains.

  9) Addition of hour-averaging output option for any chemical species.