The ICON (ICOsahedral Non‐hydrostatic) modelling framework of DWD and MPI‐M : Description of the non‐hydrostatic dynamical core

Abstract This article describes the non‐hydrostatic dynamical core developed for the ICOsahedral Non‐hydrostatic (ICON) modelling framework. ICON is a joint project of the German Weather Service (DWD) and the Max Planck Institute for Meteorology (MPI‐M), targeting a unified modelling system for global numerical weather prediction (NWP) and climate modelling. Compared with the existing models at both institutions, the main achievements of ICON are exact local mass conservation, mass‐consistent tracer transport, a flexible grid nesting capability and the use of non‐hydrostatic equations on global domains. The dynamical core is formulated on an icosahedral‐triangular Arakawa C grid. Achieving mass conservation is…