In the CCPP-Physics v2 code, each parameterization is placed in its own modern Fortran module, which facilitates model development and code maintenance. While some individual parameterization can be invoked for GMTB SCM, most users will assemble the parameterizations in suites. The parameterizations contained in CCPP-Physics v2 can be used to run two suites: FV3GFS default (with GFDL cloud microphysics) and FV3GFS with Zhao-Carr microphysics.

The FV3GFS physics suite uses the parameterizations in the following order, as defined in suite_SCM_GFS_2017_updated.xml and suite_SCM_GFS_2018_updated.xml:

The parameterizations included in the CCPP-Physics v2 are all column-based, that is, computations are performed only in the vertical. The input information for the physics include the values of the gridbox mean prognostic variables (wind components, temperature, specific humidity, cloud fraction, vater contents for cloud liquid, cloud ice, rain, snow, graupel, and ozone concentration), the provisional dynamical tendencies for the same variables and various surface fields, both fixed and variable.

The time integration of the GFS physics suite is based on the following:

The tendencies from the different physical processes are computed by the parameterizations or derived in separate interstitial routines;
The first part of the suite, comprised of the parameterizations for radiation, surface layer, surface (land, ocean, and sea ice), boundary layer, orographic gravity wave drag, and Rayleigh damping, is computed using a hybrid of parallel and sequential splitting (Donahue and Caldwell(2018) [23]), a method in which the various parameterizations use the same model state as input but feel the effect of the preceding parameterizations. The tendencies from the various parameterizations are then added together and used to update the model state.
The second part of the physics suite, comprised of the parameterizations of ozone, stratospheric $H_2O$ , deep convection, convective gravity wave drag, shallow convection, and microphysics, is computed using sequential splitting in the order listed above, in which the model state is updated between calls to the parameterization.

In addition to the physical schemes themselves, this scientific documentation also covers four modules that define physics/radiation functions, parameters and constants: