CESM Models




The ocean component of the CCSM4.0 is the Parallel Ocean Program version 2 (POP2). This model is based on the POP version 2.1 of the Los Alamos National Laboratory; however, it includes many physical and software developments incorporated by the members of the Ocean Model Working Group (see the notable improvements page for these developments).



POP2 Port Validation and Model Verification

    Before running any experiements with CCSM4.0 on a local machine, the user should make sure the POP2 code has ported to their machine properly and subsequently verify the POP2 model output.
    In a successful port, CCSM POP2 ocean-model solutions are expected to be the same "to roundoff level" as solutions generated on a trusted machine. Follow the procedure outlined in the document below to assess the validity of your ported POP2 code.
    For model verification, solutions generated on a user's local machine should produce the same climate as an identical simulation on a trusted machine. A 10-year, ocean-only control simulation forced with the Coordinated Ocean-ice Reference Experiments (CORE) Version 2 Normal Year Forcing using global, 1° resolution integrated on NCAR's bluefire machine is provided for comparison. We recommend the user conduct an identical simulation on their local machine and compare the output to that from the NCAR control simulation. Follow the procedure outlined in the document below.

POP2 Post Processing Utilities

    The scripts provided below are used to create the plots found on the CCSM4.0 Diagnostics page for the ocean model and on the POP2 "Stand Alone" Diagnostics page. These scripts are configured to run on NCAR's Data Analysis Services Group (DASG) machines (gale, gust, breeze, hail, etc.); however, you can export them to your local machine. If you are running them locally, you will need NCL, IDL, Matlab, and Ferret. You will also need to download the observational data from the repository. If you do not have access to the listed non-public software packages and the module you wish to use requires it, you may use the code provided here as an example of how to process and plot your data using your preferred data analysis software. Running these scripts on a machine other than the DASG machines is untested and unsupported. These modules are a work in progress as they were initially intended for internal use; therefore, some of the modules will fail to create a plot (or data). Updates will be made periodically.


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.