How to Run

Grids & External Parameters

Grid Files

The ICON model receives information about the horizontal grid from so-called grid files in the NetCDF format. These files store coordinates and topological index relations between cells, edges and vertices of the chosen domain. A detailed description of the content of these grid files is provided in the Necessary Input Data section of the ICON Tutorial 2024.

The grid files for ICON usually follow the nomenclature R<n>B<k>, where <n> denotes the number of root divisions and <k> the number of subsequent bisections. From <n> and <k> the resolution of the grid can be estimated by the formula:

\[\Delta x \sim \frac{5050}{n \cdot 2^k} \quad km.\]

Download Grid & External Parameter Data

A set of predefined grid and external parameter datasets is available at http://icon-downloads.mpimet.mpg.de/.

External Parameters (NWP)

Please note that this description applies to the NWP Physics Package.

External parameter datasets contain topological and climatological data that is assumed to be constant during a typical NWP integration. These datasets are aggregated to a given ICON grid using the EXTPAR Software. Like for the grid files, a more detailed description is given in the Necessary Input Data section of the ICON Tutorial 2024.

Initial & Boundary Data