Boundary Conditions

Regional CRACMM simulations require chemical boundary and initial conditions. Several tools are available to assist with this process:

General Process

  1. Obtain output from a model with a larger domain or other chemical mechanism such as MPAS-CMAQ, HEMI-CMAQ, a larger CMAQ, GEOSCF, or GEOS-Chem or the CMAQ boundary profile.

  2. Extract and map the species to the regional CRACMM domain.

Tools

  • BCON . BCON prepares chemical boundary conditions for CMAQ. Files specifying how CB6r5 species map to CRACMM are available here . BCON (and ICON) include a profile that can be used.

  • ICON . ICON prepares initial conditions. The effect of initial conditions can be removed through proper spin-up, generally at least one month. See Hogrefe et al. (2017) for information on spin-up times.

  • AQMBC . AQMBC currently supports mapping of GEOSCF to CRACMM2 for creating initial and boundary conditions.

Reference
Hogrefe, C., Roselle, S. J., and Bash, J. O.: Persistence of initial conditions in continental scale air quality simulations, Atmos Environ (1994), 160, 36-45, https://doi.org/10.1016/j.atmosenv.2017.04.009 , 2017.