ECHAM
ECHAM is an atmospheric general circulation model, developed at the Max Planck Institute for Meteorology. It forms the atmospheric component of the MPI-ESM. The ECHAM development branched from an early (ca 1987) version of the global numerical weather prediction model developed at the ECMWF, and has since been continually developed at the Max Planck Institute for Meteorology. The current version of ECHAM, ECHAM6, was developed to support the institutes contribution to the fifth and sixth phase of the coupled model intercomparison project (CMIP). The ECHAM source code is freely available to the public at large. External access to the model is provided through a licensing procedure.
Configurations
ECHAM6 is configured to run at several different resolutions:
Every version incorporates a model top at 0.01 hPa (or about 80 km), a complete representation of physical processes, and allows for coupling to an advanced representation of the terrestrial biosphere through the JSBACH submodel, as well as an advanced description of the atmospheric aerosol. For CMIP5 ECHAM6.1 was used in the LR and MR configurations. For CMIP6 ECHAM6.3 is used in LR and HR configuration.
ECHAM6 development has emphasized the need to be able to run the model in a variety of configurations, for instance as aquaplanet, as a radiative convective equilibrium version, or as a single column version of the model. Idealized coupled modeling can also be performed through the incorporation of a slab ocean version of the model.
For MPI-M users, information regarding the use of ECHAM within the MPI computing environment is available on the Redmine ECHAM Wiki page.
Extensions
At the MPI-M a version of ECHAM is developed to facilitate studies of the upper atmosphere. This version, called HAMMONIA is coupled to the MOZART chemistry scheme, extends the model top to 250 km, and incorporates additional processes relevant to rarified atmosphere.
In cooperation with the C2SM at ETH as well as researchers at the University of Oxford and the Research Center in Jülich a coupled atmosphere chemistry and aerosol climate model, 
ECHAM-HAMMOZ is also developed. ECHAM also forms the physical core of the ECHAM-MESSy modeling system developed by DLR and the MPI for Chemistry in Mainz. Different versions of ECHAM also form the basis for a number of further models being used throughout Germany and Europe.
Documentation
A scientific documentation for ECHAM6 is provided through many papers in the special issue of JAMES devoted to the MPI-ESM, including the ECHAM6 overview paper.
A scientific documentation for ECHAM5 and the predecessor to the MPI-ESM is provided in a special issue of the Journal of Climate.
Additional documentation of archival versions is provided in a series of internal reports:
MPI-Report No. 354 - E. Roeckner, R. Brokopf, M. Esch, M. Giorgetta, S. Hagemann, L. Kornblueh, E. Manzini, U. Schlese, U. Schulzweida (2004): The atmospheric general circulation model ECHAM5 Part II: Sensitivity of simulated climate to horizontal and vertical resolution PDF
MPI-Report No. 349 - E. Roeckner, G. Bäuml, L. Bonaventura, R. Brokopf, M. Esch, M. Giorgetta, S. Hagemann, I. Kirchner, L. Kornblueh, E. Manzini, A. Rhodin, U. Schlese, U. Schulzweida, A. Tompkins (2003): The atmospheric general circulation model ECHAM 5. PART I: Model description PDF
MPI-Report No. 218 - Erich Roeckner, Klaus Arpe, Lennart Bengtsson, Michael Christoph, Martin Claussen, Lydia Dümenil, Monika Esch, Marco Giorgetta, Ulrich Schlese, Uwe Schulzweida (1996): The atmospheric general circulation model ECHAM-4: Model description and simulation of present-day climate PDF
MPI-Report No. 93 - E. Roeckner, K. Arpe, L. Bengtsson, S. Brinkop, L. Dümenil, M. Esch, E. Kirk, F. Lunkeit, M. Ponater, B. Rockel, R. Sausen, U. Schleese, S. Schubert, M. Windelband (1992): Simulation of the present-day climate with the ECHAM model: Impact of model physics and resolution PDF Appendix
Contact:
Sebastian Rast
Phone: +49 40 41173 425
Email: sebastian.rast@mpimet.mpg.de