The COSMOS General Assembly determines the configuration of the board, which should not have more than 12 members, as a workable size. The members of the board need to come from institutions having signed the COSMOS–MoU. 3 of these members are the Chair and two Co-chairs; the board decides about these positions.

The current members are:

Chair: Martin Claussen; University of Hamburg and MPI for Meteorology, Hamburg, Germany
Co-Chair: Heikki Järvinen; Finnish Meteorological Institute, Helsinki, Finland
Co-Chair: Robert Sausen; DLR, Insitute for Atmospheric Physics, Oberpfaffenhofen, Germany

Martin Heimann; MPI for Biogeochemistry, Jena, Germany
Pavel Kabat; Wageningen University Research, Wageningen, The Netherlands
Rupert Klein; PIK, Potsdam, Germany
Jos Leliefeld; MPI for Chemistry, Mainz, Germany
Jørgen Nilsson; SMHI, Norkøpping, Sweden
Uwe Ulbrich; Free University Berlin, Berlin, Germany

The Scientific Dircector: Daniela Jacob; MPI for Meteorology, Hamburg, Germany