C20C+ - International CLIVAR C20C+ Detection and Attribution project

This is an international project aiming to produce a large pool of output from climate models and impact models for use in improving our understanding of extreme weather in the context of past and current climate change.
Models are run under two families of scenarios:
  • All-Hist: under the time-varying boundary conditions observed during the past few decades
  • Nat-Hist: same as All-Hist but with the anthropogenic contribution to the boundary conditions removed
This and more detailed information can be found on the C20C+ portal


No registration is required. All output from this project published online is available according to the conditions of the Creative Commons License.
The data is provided "as-is". The contributors have endeavoured to ensure quality control, however due to the large quantity of data it has not been possible to check everything in detail. If you spot anything odd in the data then please e-mail the people listed in the "contact" attribute of the NetCDF file. Errata are listed in the "details" files referenced in the NERSC data portal.
If your analyses of this data themselves produce diagnostic data or output from "impacts" models that may be of interest to other researchers, please consider contributing them to the NERSC data portal. Protocols are described on the Experiment page.

C20C+ on raijin

We rsync data directly from the NERSC server, so we have all the files available on disk, which includes all the smaller and frequently accessed files.
  • All "fixed" ("fx") variables
  • All "month" ("mon") variables
  • The following "day/atmos" ("Aday") variables: clt, hurs, huss, pr, prsn, prw, ps, psl, rlds, rsds, rsus, tas, tasmax, tasmin, ts, uas, vas
We are also contributing to the project, these files are stored separately.
The replica is currently stored in /g/data1/ua8/C20C/

the directory structure can vary depending on the institute but it's mostly:
  • <institute-id>/<model>/<experiment>/<ensemble>/<version>/<frequency>/<realm>/<variable>/<run>/<files>
While this directory structure differs from the one used for CMIP data, the definitions of realm, frequency, mip and variable names are the same. Experiments are "All-Hist" and "Nat-Hist", ensembles are like "est1"

Also the filenames are similarly structured:
  • <variable>_<mip>_<model>_<experiment>_<ensemble>_<version>_<run>_<time-period>.nc

Available sub-projects:
C20C (includes HadISST1 NOAA-OI-v2 WRAF)

The original ARCCSS contribution is stored in /g/data1/ua8/ARCCSS_data/C20C/NERSC and it has a simplified directory structure

  • <frequency>/<realm>/<variable_name>/<ensemble>/<files>
filenames are the same as for the replica, ensembles are like CMIP ensemble ie "r1i1p1".
More information on these experiment are available from their RDA record