Global Climate Model Experiment Data Archive

Welcome to the Global Climate Model Data Archive section of the Data Distribution Centre (DDC) of the Intergovernmental Panel on Climate Change (IPCC). This page is the main entry point for users who want to retrieve either data (FAR to AR4 monthly mean; AR5 in different frequencies) available at DDC or information on the models used.

About DDC GCM data archive

The DDC uses the CERA database which is run by the World Data Center Climate (WDCC) at DKRZ. Detailed information on the CERA database is available on the Web. You can look here to get more information.

The data is stored on a tape archive which is associated with the (local) database CERA. A data request will initiate a retrieval mechanism that will take some time to transfer the data from tape to disk, therefore users may have to wait before the requested data is transferred.

Data is provided in NetCDF for AR5 and otherwise in GRIB format (machine independent, self-descriptive binary formats). If you need data in GZIP (compressed ASCII) format you'll have to convert the binary data locally.

Information on both formats and the internal data structure is given here.

You can select between:

• Results from GCM-Runs for the Special Report on Global Warming of 1.5°C (SR1.5)
• Results from GCM-Runs for the Fifth Assessment Report (AR5) based on the IPCC-RCP scenarios*
• Results from GCM-Runs for the Fourth Assessment Report (AR4) based on the IPCC-SRES scenarios*
• Results from GCM-Runs for the Third Assessment Report (TAR) based on the IPCC-SRES scenarios
• Results from GCM-Runs based on the IPCC-IS92a (or similar; SAR) emission scenarios
• Results from GCM-Runs user in the First Assessment Report (FAR) (subset)

* You can get a subset of these IPCC-DDC data on storage medias here.

Download Statistics

Annual statistics and reports are available starting for 2014 at Annual IPCC-DDC statistics. Monthly statistics of the number of downloads and the download volume for IPCC-DDC data are available online:

• Total monthly downloads of IPCC-DDC data as number of downloads and download volume,
• Monthly downloads of IPCC-DDC AR5 data as number of downloads and download volume,
• Monthly downloads of IPCC-DDC AR4 data as number of downloads and download volume.

GCM data validation

One of the criteria commonly used in selecting a GCM to be used in constructing regional climate scenarios for impact assessment is the performance of the GCM in simulating the present-day climate in the region. This is evaluated by comparing the model outputs with observed climate in the target region, and also over larger scales, to determine the ability of the model to simulate large scale circulation patterns. Examples of graphical comparisons between GCM outputs and observed climate for the 1961-1990 period for subcontinental world regions can be found here.

AR5 Scenarios

AR5 Scenarios are based on scenarios of the CMIP5 (Climate Model Intercomparison Project Phase 5). Details on CMIP5 Scenarios can be found in:
Taylor, K.E., R.J. Stouffer, G.A. Meehl (2012): An Overview of CMIP5 and the experiment design. Bull. Amer. Meteor. Soc., 93, 485-498, doi:10.1175/BAMS-D-11-00094.1.
And details on the RCP Emissions and Land Use scenarios used in AR5 are described here.