The GEOS-5 AGCM consists of a hierarchy of ESMF gridded components constructed and connected using MAPL. The model's architecture is illustrated in the tree diagram below. Most of the calculations are done by components at the leafs of this tree. The composite components above the leafs serve as connectors, performing specialized connections between the children and producing combined outputs.

Components in green are those that run on the exchange grid. All other components currently run on the atmospheric grid used for the dynamics, except SURFACE, which acts as an interface between the two grids.

The root component, AGCM, connects it two children, the DYNAMICS and the COLUMN PHYSICS. The COLUMN PHYSICS consists of components that compute radiative fluxes, turbulent fluxes and surface interactions, the effects of moist processes and of sub-grid scale gravity waves. It also includes chemistry and aerosol packages. The dynamics has an option of one of two finite-volume cores.