The Model-Independent Chemisty Module (MICM) is an NCAR reinvestment project to create a unique chemistry module that can be be implemented in any atmosphere model used at NCAR. MICM will enable scientists to use and contribute to a state-of-the-art atmospheric chemistry package for local, regional and global studies, and use multiple models using the same chemistry for investigating topics like seasonal air quality prediction or urban air quality prediction. Its current implementation is strongly tied to the Chemistry Cafe in providing an interface to the scientist to fully describe the chemistry that is to be modeled in a particular implementation.
The ability to work with various models has been achieved by utilizing the Common Community Physics Package (CCPP) Framework initially developed by the Global Model Test Bed Team of the Developmental Testbed Center under sponsorship of NOAA. The first release of MICM contains the ability to run "3 component", "terminator" or any named chemistry package coming out of the "Chemistry Cafe". It is important to note that this version of MusicBox is using a slightly modified version of of the CCPP(V2). It is expected that the CCPP support infrastructure will be evolving and while the general plug-and-play philosophy will remain the same, the actual implementation details may change dramatically.
MICM's plug-and-play capabilities are limited in this initial version to four schemes: mass_quantities_util, k_rateConst, tuv_photolysis and a chemistry_driver. Two chemistry drivers, rosenbrock and mozart, are provided to allow users the ability to choose between the two and also demonstrates the ease that changes can be made to chemistry suites. Any of these schemes can be replaced with another group's own scheme simply by providing a CCPP-compliant version of their scheme. It is expected that the number of schemes contained within MICM will expand in upcoming years and become a much more complete chemistry model with variations and additional schemes provided by multiple groups.
This material is based upon work supported by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation under Cooperative Agreement No. 1852977.
Testing of MICM is currently supported in MusicBox. It is targeted for support in SIMA and other host models such as MuSICA.
Definition of Chemical Kinetics
Chemistry Cafe – A store of chemical reactions, species, and collection of reactions.
Configurator – An application to convert Chemistry Cafe data to FORTRAN to be used by a specified host model.