About us

Welcome to the webpages of the CLM-Community!

Become a Member


To give you get a brief overview over who we are and what we are aiming for:  

The CLM-Community (Climate Limited-area Modelling-Community) is an open, international network of scientists, who are employing and developing the regional climate model COSMO-CLM aka CCLM. To become a member and get involved, you should get yourself acquainted with our CLM-Community agreement and fill in the application form (→ Become a member).

map of participating countries 09 17


In summer 2015, the CLM Community had 251 scientific members from 67 climate research institutions all over the world (→ CLM-Institutions). It is the largest obliging cooperation in the field of regional climate modelling aiming to address the challenges of model development stated above, to efficiently use the computing resources and to make substantial contributions to answer the key questions of regional climate modelling.

The CLM-Community members meet every year at the general assembly in late summer (→ Assembly). Here, recent developments and exciting results are presented, further cooperations in working and project groups are decided as well as community decisions taken. In springtime, there is a second important community meeting, the user seminar together with the COSMO- and ART-Communities (→ User seminar). In the user seminar, recent developments are presented as well in the plenary and the project and working groups of both communities convene. Shortly before the user seminar, the annual training course is held in Langen for one week. All new users of COSMO and COSMO-CLM are invited to this training course to get assistance with the first steps (→ Training). 



Group picture assembly 2013

COSMO-CLM Assembly, Zurich, Switzerland, August 2013 (Photo by O. Bellprat)




The CCLM is based on LM, which was developed at Deutscher Wetterdienst (DWD) in 1999. In 2005 the CCLM became the regional Community-Model for the German climate research. Since 2007, a unified version of the weather forecast model COSMO (COnsortium for SMall scale MOdeling) and CCLM exists. The two communities COSMO and CLM work closely together in further developing the model. 2014, the unified model version COSMO 5 for weather, climate, and environmental research was released.


The current released and evaluated climate model version of the CLM-Community is the COSMO_4.8_clm17. It comes together with a recommendation for the configurations for the European domain (→ Model details).

COSMO-CLM is an atmosphere model coupled to the soil-vegetation model TERRA. Additionally, there is the possibility to use COSMO-ART (Vogel at al., 2009), which enables the calculation of the interactions of trace gases and aerosol with the atmospheric radiation. Other regional processes in the climate system like ocean and ice sheet dynamics, plant responses, aerosol-cloud interaction, and the feedback to the GCM driving the RCM are still prescribed or neglected.



The most important goal of the CLM-Community is communication to enable a harmonized model development, on cooperations and community issues themself. There are several ways to exchange information at the moment:


  • this website itself
  • the half-yearly published CLM-Community newsletter (→ Newsletter)
  • our regular meetings (→ assembly and user seminar)
  • working and project group meetings and their mailing lists (→ Mailing lists)
  • information on model development, releases,  pre- and postprocessing (→ Model)
  • the RedC forum to post and answer questions (→ RedC forum)
  • the RedC wiki (→ RedC wiki)
  • publications by the members (→ Publications)

So, you are invited to be part of our exciting community and take part in our working and project groups: Become a Member