New Earth system model of Max Planck Institute for Meteorology

After five years of developing and improving the well-known ECHAM5/MPIOM climate model of the Max Planck Institute for Meteorology (MPI-M), the new Earth system model MPI-ESM is now ready and available for use by the scientific community. The present and future workhorse of all three MPI-M departments has already been used for comparative model calculations in the context of the CMIP5 process (“Coupled Models Intercomparison Project Phase 5”). The main improvement to the previous ECHAM5/MPIOM is the coupled carbon cycle, which now allows studying feedbacks of climate change on to the carbon cycle itself. The representation of shortwave radiative transfer, surface albedo and aerosol has also been improved. The representation of the middle atmosphere as well as the land surface with interactive vegetation dynamics and the possibility of using different resolutions depending on the different questions were also incorporated into the design of the MPI-ESM. A special issue of the Journal of Advances in Modeling Earth Systems (JAMES) will be dedicated to the initial description of the MPI-ESM, through numerous papers (currently in review) by MPI-M researchers.



The MPI-ESM couples the atmosphere, ocean and land surface through the exchange of energy, momentum, water and important trace gases such as carbon dioxide. It has been used for comparative model calculations in the context of CMIP5, which constitute the German contribution to the Fifth Assessment Report of the IPCC (Intergovernmental Panel on Climate Change), scheduled for publication in late 2013. Compared to the previous version ECHAM5/MPIOM, the MPI-ESM was extended by numerous developments. It is based on the components of ECHAM6 for atmosphere and MPIOM for ocean as well as JSBACH for terrestrial biosphere and HAMOCC for the ocean´s biogeochemistry. The coupling of atmosphere and land on the one hand and ocean and biogeochemistry on the other hand is made possible by the separate coupling program OASIS3. Energy, momentum, water and CO2 are exchanged with the help of this coupling.

The most important changes and improvements of the MPI-ESM compared to the previous model ECHAM5/MPIOM are:

  • advanced/improved treatment of radiative transfer
  • improved representation of surface albedo
  • new and improved representation of the aerosol
  • much better representation of the middle atmosphere
  • a capacity to simulate at a range of different resolutions depending on the question
  • interactive vegetation dynamics
  • coupled carbon cycle

The simulation of the carbon cycle allows statements about the effects of climate change on the carbon cycle itself. The MPI-ESM has been freely available to the scientific community since February 2012, and can be accessed with a license on the MPI-M Model distribution website.



Michael Botzet (Opens window for sending emailmail), phone: (+49 40) 41173- 137