The current incarnation of the GISS series of coupled atmosphere-ocean models is available here. Called ModelE, it provides the ability to simulate many different configurations of Earth System Models — including interactive atmospheric chemistry, aerosols, carbon cycle and other tracers, as well as the standard atmosphere, ocean, sea ice and land surface components.


Model versions used for the CMIP5 and CMIP6 simulations are available via the nightly snapshots of the current code repository, including the frozen 'AR5_branch'. However, users should be aware that these snapshots are presented 'as is' and are not necessarily suitable for publication-quality experiments.

Please let us know if you intend to use this code by subscribing to our mailing list. We will then keep you (very occasionally) informed about code patches and possible improvements to the configuration.

Guidelines for Use of Model Code

Our code is freely available for download and use. Note however, that this is a work in progress and many people contribute to its development. It's important to state how much the group effort — in all the different aspects of modeling — has contributed to progress. From the people who conceive of new developments, the people who code them, the people that apply the model to new science questions, the people who find the inevitable bugs, to those who do the data processing and analyse the diagnostics, all are essential to keeping the project viable. This should be reflected on when deciding on co-authorship and acknowledgments.

The three main description papers for the ModelE2 design, historical and future simulations are now published and the authorship for those papers was very inclusive. Many other basic description papers for new developments (chemistry, ocean biology, aerosols etc.) are also now published. Not every subsequent paper needs to include everyone that contributed to any part of the model, but judging the level of contribution and how it should be acknowledged can be tricky and can lead to unnecessary complications. Authors need to work these things out individually, but some general considerations are worth thinking about:

  • If people make substantive contributions to the idea for a paper, the work, the discussion or the writing, they should be co-authors.
  • 'Honorary' co-authorship for group leads/PIs, if the previous conditions don't hold, is not encouraged.
  • If people help you out in a minor way with running models, an analysis program, a calculation, or some light editing etc., they should (at least) be acknowledged.
  • If you are building off developments that have already been published, then obviously you should reference the relevant papers, but if you are using new functionality that has not yet been described in the literature, it's probably best to discuss this with the developers directly about their expectations even if they did not directly help with your paper. The use of substantial unpublished functionality, even if modified, without acknowledgement or discussion, is strongly discouraged.

These are just guidelines and should not be taken as being definitive. Determining whether a contribution is substantive is inevitably subjective. But if there are any judgement calls to be made, try and make them in discussion with the people involved. That usually heads off any issues that might arise later. Overall, we should strive not to take the group efforts for granted or inadvertently give that impression. Time taken to acknowledge other people's contributions is often time well invested and costs little.

ModelE Documentation

Documentation is included in the distribution (under directory doc/) and is included below for reference. The User Guide includes discussion of system requirements and configuration of the distribution for any new system. For further details, see the User Guide's index.

Other available documentation includes:

General Documentation

Model documentation in the literature is usually by component, with only occasional general papers on the whole system. The most recent general papers about the ModelE CMIP5 specification and results are given in the following articles:

  • Schmidt, G.A., M. Kelley, L. Nazarenko, R. Ruedy, G.L. Russell, I. Aleinov, M. Bauer, S.E. Bauer, M.K. Bhat, R. Bleck, V. Canuto, Y.-H. Chen, Y. Cheng, T.L. Clune, A. Del Genio, R. de Fainchtein, G. Faluvegi, J.E. Hansen, R.J. Healy, N.Y. Kiang, D. Koch, A.A. Lacis, A.N. LeGrande, J. Lerner, K.K. Lo, E.E. Matthews, S. Menon, R.L. Miller, V. Oinas, A.O. Oloso, J.P. Perlwitz, M.J. Puma, W.M. Putman, D. Rind, A. Romanou, M. Sato, D.T. Shindell, S. Sun, R.A. Syed, N. Tausnev, K. Tsigaridis, N. Unger, A. Voulgarakis, M.-S. Yao, and J. Zhang, 2014: Configuration and assessment of the GISS ModelE2 contributions to the CMIP5 archive. J. Adv. Model. Earth Syst., 6, no. 1, 141-184, doi:10.1002/2013MS000265.
  • Shindell, D.T., O. Pechony, A. Voulgarakis, G. Faluvegi, L. Nazarenko, J.-F. Lamarque, K. Bowman, G. Milly, B. Kovari, R. Ruedy, and G. Schmidt, 2013: Interactive ozone and methane chemistry in GISS-E2 historical and future climate simulations. Atmos. Chem. Phys., 13, 2653-2689, doi:10.5194/acp-13-2653-2013.
  • Kim, D., A. Del Genio, and M.-S. Yao, 2011. Moist Convection scheme in ModelE2, Technical note (PDF).
  • Miller, R.L., G.A. Schmidt, L.S. Nazarenko, N. Tausnev, S.E. Bauer, A.D. Del Genio, M. Kelley, K.K. Lo, R. Ruedy, D.T. Shindell, I. Aleinov, M. Bauer, R. Bleck, V. Canuto, Y.-H. Chen, Y. Cheng, T.L. Clune, G. Faluvegi, J.E. Hansen, R.J. Healy, N.Y. Kiang, D. Koch, A.A. Lacis, A.N. LeGrande, J. Lerner, S. Menon, V. Oinas, C. Pérez García-Pando, J.P. Perlwitz, M.J. Puma, D. Rind, A. Romanou, G.L. Russell, M. Sato, S. Sun, K. Tsigaridis, N. Unger, A. Voulgarakis, M.-S. Yao, and J. Zhang, 2014: CMIP5 historical simulations (1850-2012) with GISS ModelE2. J. Adv. Model. Earth Syst., 6, no. 2, 441-477, doi:10.1002/2013MS000266.
  • Nazarenko, L., G.A. Schmidt, R.L. Miller, N. Tausnev, M. Kelley, R. Ruedy, G.L. Russell, I. Aleinov, M. Bauer, S. Bauer, R. Bleck, V. Canuto, Y. Cheng, T.L. Clune, A.D. Del Genio, G. Faluvegi, J.E. Hansen, R.J. Healy, N.Y. Kiang, D. Koch, A.A. Lacis, A.N. LeGrande, J. Lerner, K.K. Lo, S. Menon, V. Oinas, J.P. Perlwitz, M.J. Puma, D. Rind, A. Romanou, M. Sato, D.T. Shindell, S. Sun, K. Tsigaridis, N. Unger, A. Voulgarakis, M.-S. Yao, and J. Zhang, 2015: Future climate change under RCP emission scenarios with GISS ModelE2. J. Adv. Model. Earth Syst., 7, no. 1, 244-267, doi:10.1002/2014MS000403.

Note: PDF documents require the free Adobe Reader or compatible viewing software to be viewed.

Earlier articles relating to the CMIP3 model are as follows:

More documentation is available within the distribution. Please let us know if any of the information in these files is out-of-date or otherwise incomplete. NOTE: we are updating the documentation — please excuse any out-of-date information.

Source Code Repository

View source code in the repository (access limited to approved users within the domain) for latest updates. This link allows you to view all the source files currently in the central Git repository together with their older versions. You can also make comparisons between different versions of the same file.

CMIP Model Configurations and Descriptions

CMIP6 Configuration and Description

The description of planned configurations for the GISS contributions to the CMIP6 archive can be found here. As this project develops and as output data is made available through ESGF and elsewhere, this page is where updates will be posted.

CMIP5 Configuration and Description

The description of configurations for the GISS contributions to the CMIP5 archive can be found here. Initial and boundary condition files for these configurations (and many others) can be downloaded from the NCCS portal.

Output from the CMIP5 simulations is available via the Earth System Grid Federation (ESGF) nodes at NASA GSFC and LLNL. There is also direct web access to our data (email us for details).

CMIP3 Configuration and Description

GISS submitted a number of different configurations to the CMIP3 model data repository at PCMDI. Information about the configurations and about updates and the known issues are provided on ModelE CMIP3 simulations page.

The frozen version of the ModelE code used for CMIP3 simulations and the controls for model description papers is denoted as ModelE1 (internal version number 3.0, dated Feb. 1, 2004). This code can be freely downloaded (as a 1.2 MB gzip-ed tar file) from modelE1.tar.gz.

Boundary and initial conditions for the CMIP3 version can be downloaded from fixed.tar.gz (191 MB). This is a large amount of data due to things like transient 3-D aerosol concentrations etc. A wider selection of input data (encompassing many different configurations, but mainly for a more up-to-date codebase are available on the NCCS Dataportal. There are more variants of this data available internally, so if you do not find the configuration you'd like, let us know and we may be able to help you.

If you require any further details on these configurations, please read the submitted papers, or contact us as described below.

Other ModelE Simulations

The results of various ModelE simulations conducted by GISS scientists may be found in the Datasets section of the GISS website.


Please address all inquiries about the ModelE code to:

Dr. Gavin Schmidt
NASA Goddard Institute for Space Studies
2880 Broadway, New York, NY 10025 USA