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About Us

Welcome to the webpage of the Climate Limited-area Modelling Community!

Become a Member

The CLM-Community (Climate Limited-area Modelling-Community) is an open, international network of scientists, who develop and apply the regional climate model COSMO-CLM a.k.a. CCLM and ICON-CLM.

To become a member of the CLM-Community and get involved, you should become familiar with our CLM-Community agreement and fill in the application form (→Become a member).

In 2018, the CLM Community had 250 scientific members from 77 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.

Institutions CLM

The CLM-Community members meet every year at the general assemblyin late summer (→ Assembly). At the assembly, recent developments and exciting results are presented, further cooperations in working and project groups are initiated and community decisions are taken.

In spring, there is a second important community meeting, ICCARUS(ICON COSMO CLM ART User Seminar) together with the ICON-, COSMO- and ART-Communities (→ ICCARUS). At ICCARUS, recent model developments are presented in joint plenary sessions and in more detail also in project and working groups of both communities.

Usually shortly after ICCARUS, the annual training coursetakes place in Langen for one week. All new users of ICON-LAM and COSMO-CLM are invited to this training course to get assistance with the first steps (→ Training). 


CLM-Community Assembly 2018 in Karlsruhe (Photo by N. Laube)


The COSMO-CLM is based on the "Lokalmodell" (LM), which was developed at Deutscher Wetterdienst (DWD) in 1999. In 2005 COSMO-CLM became the regional Community-Model for climate research in Germany. Since 2007, a unified version of the weather forecast model COSMO (COnsortium for SMall scale MOdeling)and COSMO-CLM 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_5.0_clm6. It comes together with a recommended configuration 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. Research efforts are aimed at coupling of a regional ocean with NEMO for the North and Baltic Seas as well as the Mediterranean Sea. NEMO also includes a sea ice module. Other regional processes in the climate system like the 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
  • the biannual 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)

You are invited to be part of our exciting community and take part in our working and project groups:

Become a Member