General descriptions

• This paper provides an overview of the project.
• The main technical brochure describing the project (updated 2014-02-04)
• A new short description of the project in CLIVAR Exchanges (2014)

  Generation of experimental setups

• This paper describes the generation and testing of the All-Hist/est1 and Nat-Hist/CMIP5-est1 sea surface temperatures and sea ice coverage
• See the publications page for a further list of experiment descriptions particular to each model.

  Output data

• The list of the requested output and requested metadata formats for output from climate models and wind-wave models (updated 2017-09-27)

  Data portal

• The description structure of the data portal and file naming conventions (updated 2017-03-09)
• File naming conventions for most non-climate variables have still not been developed. Please contact dstone@lbl.gov for additions.

All-Hist/est1 experiment

• This is a time-varying estimate of the boundary conditions of the climate that actually occurred. It is to be used by all climate models.
• Documentation (updated 2021)
• See table below for available files.

Nat-Hist/CMIP5-est1 experiment

• This is a time-varying estimate of what the boundary conditions of the climate system might have been like if historical anthropogenic emissions had never occurred. The sea surface temperatures are estimated by calculating a multi-model average of the attributable ocean warming estimated CMIP5 models and substracting that from observed values. This is the benchmark estimate of the natural world for use across models in the C20C+ D&A Project.
• Documentation (updated 2021)
• See table below for available files.

Nat-Hist/* experiments

• These are additional (to Nat-Hist/CMIP5-est1) time-varying estimates of what the boundary conditions of the climate system might have been like if historical anthropogenic emissions had never occurred. The sea surface temperatures are estimated by subtracting various estimates of the ocean warming attributable to anthropogenic emissions. Various estimates are used, varying across models.
• Documentation
  • Coming soon.
• See table below for available files.

Table of available sea surface temperature (SST) and sea ice concentration (SIC) files

Notes

• Abbreviations:
  • SSTs: Sea surface temperatures (labeled as "tos" in the files)
  • SICs: Sea ice concentrations (labeled as "sic" in the files)
• Table headings:
  • Grids: The spatial grid on which the data is provided. The HadISST1, Hurrell et alii (2008), and NOAA OI.v2 grids are identical (1°×1° polar grid).
  • Attributable ΔSSTs: A time-varying gridded estimate of the warming attributable to historical anthropogenic emissions. This array should be subtracted from an observational product to estimate the sea surface temperatures for the Nat-Hist experiment.
  • Reference SST and SIC product: The observational SST and SIC product from which an attributable ΔSST warming estimate is subtracted to produce a Nat-Hist estimate of SSTs and SICs.
  • Estimated SSTs and SICs: For All-Hist/est1 these are the observed sea surface temperatures and sea ice concentrations. For Nat-Hist, these are estimated sea surface temperatures and sea ice concentrations for the relevant Nat-Hist experiment, calculated by subtracting the ΔSST file from the specified reference SST and SIC product.
• Naming conventions:
  • Hurrell et alii (2008): If you need estimates based on the Hurrell et alii (2008) observational product then simply use the files based on the NOAA OI.v2 product in the table. Hurrell et alii (2008) and NOAA OI.v2 are identical over their common period (1982-present). What is labeled in the table as being based on NOAA OI.v2 is actually based on a concatenation of Hurrell et alii (2008) and the operational updates of NOAA OI.v2.
• Files:
  • Format: The files are in the NetCDF format, following "CF" conventions (e.g. which have also been adopted by CMIP5).
  • Time periods: A number of files are available for each of the experiment-grid combinations, each covering different periods.

  NetCDF formating tools

• NetCDF formating code for the C20C+ D&A Project. A bash script created for performing some standardisation, metadata additions, and checks specifically for this project. Requires CDO and NCO. Current version of the generic code: v5-0-20170309.
• The CDO (Climate Data Operators) package from the Max-Planck-Institute für Meterologie
• The ESGF CMOR Data Converter, used by CMIP5 for properly formating files. Needs modification for application on this project.
• The NCO (NetCDF Operator) package from the University of California, Irvine

  Generation of ocean/sea ice surface boundary conditions

• C20C dtos v2 IDL package. IDL (GDL compatible) code for generating the sea surface temperature and sea ice concentration input data used in the C20C+ D&A project simulations. For current version, follow above link.