CESM Models

CCSM4.0 Public Release

About CCSM 4.0

The Community Climate System Model (CCSM) is a coupled climate model for simulating the earth's climate system. Composed of four separate models simultaneously simulating the earth's atmosphere, ocean, land surface and sea-ice, and one central coupler component, the CCSM allows researchers to conduct fundamental research into the earth's past, present and future climate states. Please see the brief overview of the notable model improvements

It is important to note that CCSM4 is a subset of CESM1. The CCSM4.0 code base is frozen and all future model updates will occur from the CESM1.0 code base. In addition, although CESM1 supersedes CCSM4, users can run all CCSM4 experiments from the CESM1 code base.

Model Output Data and Diagnostics

Model Documentation



External Library Documentation

Model Input Data

The input data necessary to run all supported component sets is made available from a public Subversion input data repository. Note that the inputdata repository has much more data in it than you need to run CCSM4.0 ---- DO NOT attempt to svn checkout the whole input data repository. The CCSM4.0 User's Guide (see above) explains how to obtain the subset of input data required for your needs.

Performance and Load Balancing Data

The CCSM4 Timing Table provides performance data that will continue to evolve due to changes in the model, machine hardware and input from the user community.


CESM Project

The Community Earth System Model (CESM) is a fully-coupled, global climate model that provides state-of-the-art computer simulations of the Earth's past, present, and future climate states.

CESM is sponsored by the National Science Foundation (NSF) and the U.S. Department of Energy (DOE). Administration of the CESM is maintained by the Climate and Global Dynamics Laboratory (CGD) at the National Center for Atmospheric Research (NCAR).

Model Source Code

Copyright and Terms of Use

All CCSM source code is subject to the following Copyright Notice and Disclaimer.

Acquiring the Code

CCSM source code is distributed through a public Subversion code repository. This code can be checked out using Subversion client software, such as the command tool svn, or simply viewed with a web browser.

A short registration is required to access the repository. After registering, you will receive an email containing a user name and password that is necessary to gain access to the repository.

Acquistion of the code is more fully described in the CCSM4.0 User's Guide.

Version Summaries and Known Problems

The following table lists the available versions of code along with their test record and any known problems in the code.

Reporting a Problem

If you have any problems, please first read the User's Guide including the sections on FAQs and Use Cases. Please also refer to the CCSM Bulletin Board, which is in place to facilitate communication within the CCSM community. Finally, please also refer to the Known Problems entries that are provided with every release and release update. If questions or problems still exist, then please send an email to help@cgd.ucar.edu. Support questions will be answered as resources are available.