Geoscientific Model Development www.geosci-model-dev.net 1991-959X 1991-9603 2 2 2009 10.5194/gmd-2-231-2009 http://www.geosci-model-dev.net/2/231/2009/ http://www.geosci-model-dev.net/2/231/2009/gmd-2-231-2009.html http://www.geosci-model-dev.net/2/231/2009/gmd-2-231-2009.pdf 231 251 2009-12-07 Icosahedral Shallow Water Model (ICOSWM): results of shallow water test cases and sensitivity to model parameters P. Rípodas maria-pilar.ripodas@dwd.de A. Gassmann J. Förstner D. Majewski M. Giorgetta P. Korn L. Kornblueh H. Wan G. Zängl L. Bonaventura T. Heinze Deutscher Wetterdienst, Offenbach, Germany Max Planck Institute for Meteorology, Hamburg, Germany now at: Politecnico di Milano, Milan, Italy now: freelance scientist The Icosahedral Shallow Water Model (ICOSWM) has been a first step in the development of the ICON (acronym for ICOsahedral Nonhydrostatic) models. ICON is a joint project of the Max Planck Institute for Meteorology in Hamburg (MPI-M) and Deutscher Wetterdienst (DWD) for the development of new unified general circulation models for climate modeling and numerical weather forecasting on global or regional domains. A short description of ICOSWM is given. Standard test cases are used to test the performance of ICOSWM. The National Center for Atmospheric Research (NCAR) Spectral Transform Shallow Water Model (STSWM) has been used as reference for test cases without an analytical solution. The sensitivity of the model results to different model parameters is studied. The kinetic energy spectra are calculated and compared to the STSWM spectra. A comparison to the shallow water version of the current operational model GME at DWD is presented. The results presented in this paper use the ICOSWM version at the end of 2008 and are a benchmark for the new options implemented in the development of the ICON project. 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