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ACC GCM Data archives

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This page provides links to outputs from the ENSEMBLES anthropogenic climate-change (ACC) global simulations.


Stream 1 simulations:

These anthropogenic climate-change runs simulate anthropogenic and natural forced climate response for the historical period from 1860 to present and projected response to 2100 for three SRES scenarios: A2, A1B and B1. These centennial predictions have been performed with seven different coupled atmosphere-ocean general circulation models (AOGCMs) of the ENSEMBLES partners: BCM2 (NERCS-BCCR), CNRM-CM3 (CNRM), ECHAM5/MPI-OM (MPIMET, DMI), EGMAM (FUB), HadCM3, HadGEM1 (both METO-HC) and IPSL-CM4 (IPSL).

Results from these simulations are reported in the IPCC working group 1 Fourth Assessment Report and provide the focus of ENSEMBLES climate change downscaling activities.

Stream 2 simulations:

These stream 2 historical simulations consist of a first simulation with anthropogenic forcings only, including the land use fraction, for the period 1860-2000 and an optional second simulation with the addition of observed natural forcing. The projected future response uses the A1B scenario and the new stabilisation E1 scenario simulated by the IMAGE model. Stream 2 simulations use improved models - some including carbon cycle models and aerosol transport.

More detail about the forcings and simulations can be found on the RT2A website

Data archives:

Stream 1 and 2 output for a common subset of variables is available from the ENSEMBLES CERA archives and metadata are accesible from the ENSEMBLES RT2A web page. Some Stream 1 output is also available from the IPCC WGI PCMDI data base and from the IPCC Data Distribution Centre (DDC). Additional output is available from the individual modelling centres.

Links to data archives Details Access
CERA This is the central ENSEMBLES ACC GCM archive based in Hamburg. It provides access to an agreed subset of monthly and daily output in netCDF format from the ENSEMBLES simulations. Users can utilise the graphical interface or a command-line based program. See ENSEMBLES data policy
ENSEMBLES RT2A Links to the CERA database and other download links. From the RT2A results page there is access to:
  • list of the available simulations and model documentation
  • list of variables and output intervals
  • technical details on forcing fields and how to construct the datafiles to be stored
PCMDI data archives These archives consist of a subset of coupled ocean-atmosphere GCM output in netCDF format to support the Working Group I component of the IPCC's 4th Assessment Report. It includes ouput from non-ENSEMBLES models.

Registration with IPCC required

data archives
IPCC Fourth Assessment Report monthly output can be downloaded in GRIB or netCDF format or ordered on DVD. It includes ouput from non-ENSEMBLES models. Public



A series of ENSEMBLES reports provides technical descriptions and analyses of the ACC GCM outputs.

Links to data archives Details Access
D2A.2 Simulations based on existing atmospheric and coupled ocean-atmosphere-sea-ice models over the past 100 years (mean climate, interannual variability and trends) ENSEMBLES partners
D2A.3 First set (Stream 1) of scenario experiments for the prediction of future climate using existing coupled ocean-atmosphere climate models ENSEMBLES partners
D2A.3.2 Data and report on stream one simulations for the prediction of future climate ENSEMBLES partners
M2A.2.2 Provision of stream one simulations of the 20th century climate evolution on servers or on request ENSEMBLES partners
M2A.3.2 Provision of stream one 21st century climate predictions on servers or on request ENSEMBLES partners
D2A.4.4 Preliminary version of the ENSEMBLES view into the WDCC archive ENSEMBLES partners
D2A.4.5 Stream 1 data centrally stored in distributed archive (CERA, PCMDI) Public
D2A.4.6 20th century runs of stream 2: all data archived centrally in CERA data base Public
D2B.17 GCM-based predictor data set for statistical downscaling (Task 2B.2.5) Public
D4.1.1 Characterisation of the water vapour and cloud feedbacks in response to anthropogenic forcing Public
D5.5 Preliminary report on systematic errors in the ENSEMBLES models Public
D5.14 Assessment of the impact of model resolution on the simulation of ENSO Public
D5.16 Assessment of the representation of cloud regimes in the tropical regions Public
D5.17 Assessment of the representation of the monsoon and its teleconnection with the ocean variability from IPCC scenarios with the European models Public
D5.19 Scientific paper on the impact of the underestimates of Northern Hemisphere blocking in seasonal and climate change predictions of European winter precipitation Public
D5.25 Understanding the double ITCZ in the eastern Pacific Public
D5.26 Model performance in the Indo Pacific sector Public
M2A.3.3 Specification of the forcings for the 21st C. simulations in stream 2 Public
M4.2.3 Preliminary assessment of changes in large scale, low frequency modes of variability under anthropogenic climate change based on scenario and time slice experiments Public

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