In response to a proposed activity of the World Climate Research Programme (WCRP) Working Group on Cloupled Modelling (WGCM), PCMDI volunteered to collect model output contributed by leading modeling centers around the world. Climate model output from simulations of the past, present and future climate was collected by PCMDI mostly during the years 2005 and 2006, and this archived data constitutes phase 3 of the Coupled Model Intercomparison Project (CMIP3). In part, the WGCM organized this activity to enable those outside the major modeling centers to perform research of relevance to climate scientists preparing the Fourth Asssessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC). The IPCC was established by the World Meteorological Organization and the United Nations Environmental Program to assess scientific information on climate change. The IPCC publishes reports that summarize the state of the science.
This unprecedented collection of recent model output is officially known as the "WCRP CMIP3 multi-model dataset." It is meant to serve IPCC's Working Group 1, which focuses on the physical climate system -- atmosphere, land surface, ocean and sea ice -- and the choice of variables archived at the PCMDI reflects this focus. A more comprehensive set of output for a given model may be available from the modeling center that produced it.
With the consent of participating climate modelling groups, the WGCM has declared the CMIP3 multi-model dataset open and free for non-commercial purposes. After registering and agreeing to the "terms of use," anyone can now obtain model output via the ESG data portal, ftp, or the OPeNDAP server.
As of July 2009, over 36 terabytes of data were in the archive and over 536 terabytes of data had been downloaded among the more than 2500 registered users. Over 250 journal articles, based at least in part on the dataset, have been published or have been accepted for peer-reviewed publication. Latest statistics can be found at: [links from the source WWW page] 1) usage, 2) download rate, 3) CMIP3 subprojects, and 4) publications. [Source: http://cmip-pcmdi.llnl.gov/cmip3_overview.html as retrieved on 2009-08-19]
Note: Calendars are different from one model project to another, e.g. it may be Gregorian, 365days/year, 360days/year.
| Keyword Type | Keyword | Keyword thesaurus Name |
|---|---|---|
| theme | GLOBAL CHANGE > Global climate models | AGU |
| theme | Climate | GEOSS |
| theme | Atmosphere > Atmospheric Pressure > Surface Pressure, Atmosphere > Atmospheric Radiation > Radiative Flux, Atmosphere > Atmospheric Temperature, Atmosphere > Atmospheric Water Vapor, Atmosphere > Atmospheric Winds, Atmosphere > Clouds, Atmosphere > Precipitation, Oceans > Ocean Circulation > Ocean Currents, Oceans > Ocean Heat Budget, Oceans > Ocean Temperature, Oceans > Salinity Density > Salinity, Terrestrial Hydrosphere > Snow Ice > Snow Depth, Terrestrial Hydrosphere > Surface Water > Runoff | GCMD |
The directory structure of CMIP3 data in DIAS follows that of the FTP site of PCMDI. It has 7 levels of directories: 1:project, 2:scenario (or experiment), 3:submodel, 4:frequency, 5:variable, 6:model, and 7:run.
| Distribution Format name | version | specification |
|---|---|---|
| NetCDF | 3 | see http://www.unidata.ucar.edu/software/netcdf/ |
| CF Convention | 1.0 | see http://cf-pcmdi.llnl.gov/documents/cf-conventions |
In consulating with the IPCC Working Group 1 cochairs, in late 2003 WGCM {World Climate Research Program (WCRP) / Climate Variability and Predictability (CLIVAR) Working Group on Coupled Models (WGCM)} embarked on a process to coordinate a set of experiments covering many aspects of climate variability and change that could be performed by as many modeling groups as possible with state-of-the-art global coupled climate models [sometimes referred to as atmosphere-ocean general circulation models (AOGCMs)]. The model data were then collected and made available for analysis. However, a crucial part of this effort was to archive and actually organize the data so that they were readily available to the international climate science community for analysis. PCMDI agreed to take on this considerable challenge, which was destined to be the third phase of CMIP, or CMIP3. PCMDI's role proved to be crucial in CMIP3, the largest international global coupled climate model experiment and multimodel analysis effort ever attempted. [Source: Meehl et al. (2007, see Reference), 1384 - 1385.]
See "Errata" web page listed among "Online Resource" in "Dataset Overview" section.
These data are for use in research projects only. A 'research project' is any project carried out by an individual or organized by a university, a scientific institute, or similar organization (private or public) for non-commercial research purposes only. Results based on these data must be submitted for publication in the open literature without any delay linked to commercial objectives.
An additional restriction is that the UK Met. Office / Hadley Centre requires strict adherence to the conditions set forth in their "License Statement", which applies to their model output:
"These data are licensed for use in Research Projects only. A 'Research Project' is any project organised by a university, a scientific institute, or similar organisation (private or public), for non-commercial research purposes only. A necessary condition of the recognition of non-commercial purposes is that all the results obtained are openly available at delivery costs only, without any delay linked to commercial objectives, and that the research itself is submitted for open publication.
Data provided by the UK Met. Office / Hadley Centre are expected to be acknowledged by:
(c) Crown copyright 2005, Data provided by the Met Office Hadley Centre"
In first making reference to the data obtained from the CMIP3 archive, please include the phrase "the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset". Subsequent references within the same publication might refer to the data with terms such as "CMIP3 data", "the CMIP3 multi-model dataset", "the CMIP3 archive", or the "CMIP3 dataset".
Whenever you publish research based on model output from the CMIP3 database, you should include the following acknowledgement:
"We acknowledge the modeling groups, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) and the WCRP's Working Group on Coupled Modelling (WGCM) for their roles in making available the WCRP CMIP3 multi-model dataset. Support of this dataset is provided by the Office of Science, U.S. Department of Energy."
[Note that the acronyms, WCRP and CMIP3, should have already appeared in the main text of your article, where they were presumably defined. You may also have already defined "PCMDI" and "WGCM", which would allow you to simply refer to them here using the acronyms.]
You may also find it useful to reference the following article, which provides an overview and documentation of the CMIP3 modelling activity:
Meehl, G. A., C. Covey, T. Delworth, M. Latif, B. McAvaney, J. F. B. Mitchell, R. J. Stouffer, and K. E. Taylor, 2007: The WCRP CMIP3 multi-model dataset: A new era in climate change research, Bulletin of the American Meteorological Society, 88, 1383-1394.
[Source: http://www-pcmdi.llnl.gov/ipcc/info_for_analysts.php#Terms_of_use as retrieved on 2009-08-19]