ICON Climate Limited-area Mode - ICON-CLM

The ICON modelling framework

The ICON (ICOsahedral Nonhydrostatic) modelling framework (Zängl et al, 2015 ) is a joint project of Deutscher Wetterdienst (DWD), Max-Planck-Institute for Meteorology (MPI-M), the German Climate Computing Center (DKRZ), the Karlsruhe Institute of Technology (KIT) and the Center for Climate Systems Modeling (C2SM) for developing a unified next-generation global numerical weather prediction and climate modelling system. The ICON modelling framework became operational in DWD's forecast system in January 2015. Starting from 21 July 2015 model simulations have been complemented by a nesting region over Europe. Since January 2021, the convection-permitting model setup ICON-D2 (i.e. using the limited-area mode of ICON) runs operationally at DWD. End of January 2024, ICON was released under an open source license (see for further information). 

The ICON modelling framework offers a wide range of possibilities for applications for all temporal and spatial scales. ICON can be used for global and regional numerical weather prediction as well as for global and regional climate simulations. The Climate Limited-area Mode of ICON (ICON-CLM, Pham et al. 2021 ) is developed by the CLM Community. It is based on the limited-area mode of ICON and includes further developments and adjustments that are necessary for regional climate simulations. The CLM Community is the key development partner of DWD for the further development of ICON in the field of regional climate modelling and has signed a development partnership agreement with DWD in January 2021. 


A first version of ICON-CLM has been developed. The first recommended setup will be made available for CLM Community members as soon as the tests are completed. If you want to contribute to the development process, please have a look at the WG MODEV page and contact the coordinator of the working group.


Much information about ICON is already available from different sources. The listing below provides a non-exhaustive overview of the information that is publicly available. CLM-Community members can find further information about ICON-CLM and related topics in the CLM-Community Wiki 🔑. A namelist overview is distributed with the ICON code (see Namelist_overview.pdf in the directory doc).