Overview CMIP6 Experimental Design and Organization

The overview paper on the CMIP6 experimental design and organization has now been published in GMD (Eyring et al., 2016). This CMIP6 overview paper presents the background and rationale for the new structure of CMIP, provides a detailed description of the CMIP Diagnostic, Evaluation and Characterization of Klima (DECK) experiments and CMIP6 historical simulations, and includes a brief introduction to the 23 CMIP6-Endorsed MIPs.

A brief summary can be found in the following overview presentation (CMIP6FinalDesign_GMD_180329.pdf) and below. After a long and wide community consultation, a new and more federated structure has been put in place. It consists of three major elements:

  1. a handful of common experiments, the DECK (Diagnostic, Evaluation and Characterization of Klima) and CMIP historical simulations (1850 – near-present) that will maintain continuity and help document basic characteristics of models across different phases of CMIP,
  2. common standards, coordination, infrastructure and documentation that will facilitate the distribution of model outputs and the characterization of the model ensemble, and
  3. an ensemble of CMIP-Endorsed Model Intercomparison Projects (MIPs) that will be specific to a particular phase of CMIP (now CMIP6) and that will build on the DECK and CMIP historical simulations to address a large range of specific questions and fill the scientific gaps of the previous CMIP phases.



Overview of CMIP6 Status

Deliverable     Status   Notes 
 CMIP6 experimental design    Finalized (see here)   The GMD Special Issue on the CMIP6 Experimental Design
 Guidance for modelers    Available (see here)   Detailed summary of requirements for CMIP6 modelers
 Guidance for data managers    Scheduled release: June 2018   Summary describing process for contributing CMIP6 output to the ESGF data archive
 Guidance for data users    Scheduled release: June 2018   Roadmap for obtaining CMIP6 model output
 CMIP6 Terms of Use   Finalized (see here)   Licensing restrictions and requirements for citing and acknowledging those who have made CMIP6 possible
Forcing datasets for DECK and historical simulations   Finalized and available on input4MIPs   Detailed summary of the CMIP6 forcing datasets 
Forcing datasets for future scenarios  

Land use scenarios available on input4MIPs;
Scheduled release for GHG concentrations and emissions end of May 2018; for ozone/nitrogen concentrations and aerosol forcings mid-August 2018

  Detailed summary of the CMIP6 forcing datasets 
CMIP6 data request   Near-final; available for use (see here)   Specification of model output to be saved from each simulation
Participating Model Groups   Registered   List of institutions (see here)
List of models (see here)
ESGF portal to CMIP6 model output    Opens end of June 2018    
Availability of DECK and historical simulations on ESGF   Not yet available   First output expected when ESGF opens; in Fall 2018, most groups are expected to begin contributing output
Availability of CMIP6-Endorsed MIP experiments on ESGF   Not yet available   Status of all 23 CMIP6-Endorsed MIPs at their websites (see here)
CMIP6 documentation (ES-DOC)   In preparation (see here)    
Routine evaluation and analysis of CMIP6 models   Ready for use as CMIP6 model output is submitted to the ESGF  

Routine model evaluation with ESMValTool set up for CMIP6 model output (see here)
Will be complemented by results from PCMDI metrics package (website to be announced)

CMIP6 Terms of Use

To enable modeling groups and others who support CMIP6 to demonstrate its impact (and secure ongoing funding), you are required to cite and acknowledge those who have made CMIP6 possible. You also must abide by any licensing restrictions. Please follow the CMIP6 Terms of Use (see here).

CMIP6 Special Issue

A CMIP6 Special Issue is published in GMD (see here). This special issue describes the new design and organization of CMIP and the suite of experiments of its next phase (i.e., CMIP6) in a series of invited contributions. The description of the experiments and forcing data sets define CMIP6 in detail. The papers provide the required information to produce a consistent set of climate model simulations that can be scientifically exploited to address the three broad scientific questions of CMIP6: (1) How does the Earth system respond to forcing?, (2) What are the origins and consequences of systematic model biases?, and (3) How can we assess future climate changes given climate variability, predictability and uncertainties in scenarios? The special issue will include an overview paper on the CMIP6 design and organization, contributions from CMIP6-endorsed MIPs and descriptions of the forcing data sets. 

CMIP6 Data Request

The CMIP6 Data Request is coordinated by the WGCM Infrastructure Panel

Technical Requirements for CMIP6 Participation

A Guide to the technical requirements for CMIP6 Participation is available at https://pcmdi.llnl.gov/CMIP6/Guide/.

This guide is sub-divided into three parts distinguished by the groups served:

  • Modelers carrying out CMIP6 simulations, Data managers responsible for data node operations, and Data users analyzing and making use of CMIP6 model output.

Model groups that participate in CMIP6 will have to register by following the steps outlined under “1. Requirements and expectations” at https://pcmdi.llnl.gov/CMIP6/Guide/modelers.html, including a registration of the scientific contacts with CMIP Panel Chair, This email address is being protected from spambots. You need JavaScript enabled to view it..

CMIP6 Forcing Datasets for DECK and Historical Simulations

The CMIP6 forcing datasets needed for the DECK, historical, and CMIP6-Endorsed MIP experiments are briefly described at http://goo.gl/r8up31. That document also provides links to the forcing data itself and to documentation.

  • The CMIP Panel has released the CMIP6 Forcing Datasets for DECK and Historical Simulations (v1.0) on 20 December 2016. At http://goo.gl/r8up31 and in input4MIPs, this is now version 6.0.0 (20th December 2016) - Initial DECK and historical forcings dataset release.
  •  6.1.0 (17th May 2017) - This version is the updated official CMIP6 forcings dataset collection. It supersedes the original 6.0.0 version released on the 20th December 2016. Two key datasets from the original release have been revised:
  • The latest official CMIP Panel Release of the CMIP6 Forcing Datasets is v6.2.1 (6th October 2017). Compared to the previous CMIP Panel release (dataset collection v6.1.1; May 2017), the new dataset collection incorporates updates to the CEDS (unrealistic small aircraft emissions before 1920 are set to zero) and in the IACETH (stratospheric aerosols) forcing datasets (unrealistic volcanic emissions in 1972 were removed and a time-varying background in SAOD introduced). Please refer to the CMIP6_Forcing_Datasets_Summary document for more detailed version information.

Please always check at http://goo.gl/r8up31 for minor updates compared to the official CMIP Panel releases. Not all of the other datasets have been released for use in CMIP6, and that is clearly indicated in the document. All forcing datasets are described in the CMIP6 Special Issue and we encourage the community to participate in the open discussion.

History of emission production see here


CMIP6 Model Evaluation System

Contacts: This email address is being protected from spambots. You need JavaScript enabled to view it. and This email address is being protected from spambots. You need JavaScript enabled to view it. 

Over the last decades significant progress has been made in model evaluation. The CMIP community has now reached a critical juncture at which many baseline aspects of model evaluation need to be performed much more efficiently to enable a systematic and rapid performance assessment of the large number of models participating in CMIP. Such an evaluation system will be implemented for CMIP6. Our initial goal is that two capabilities will be used to produce a broad characterization of CMIP DECK and historical simulations as soon as new CMIP6 model experiments are published to the Earth System Grid Federation (ESGF):

At the WGCM meeting, it was decided that the results of these tools can be displayed on a public (rather than a password restricted) website. The results will initially be water-marked until a quality control has occurred. This strategy was supported by the WGCM.

(a) the Earth System Model Evaluation Tool (ESMValTool, Eyring et al., 2016a) is a community-developed diagnostic and performance metrics tool for the evaluation of Earth system models with observations. It includes other well-established model evaluation packages such as the NCAR Climate Variability Diagnostics Package (CVDP, Phillips et al., 2014). The collection of standard namelists for example allows to reproduce the figures from the climate model evaluation chapter of IPCC AR5 (Chapter 9) and parts of the projection chapter (Chapter 12). The ESMValTool is available as open source software on GitHub (https://github.com/ESMValGroup/ESMValTool). The website at http://cmip-esmvaltool.dkrz.de/ already shows results produced with the ESMValTool for CMIP5 simulations. This website will be updated with CMIP6 results as soon as the model output is submitted to the ESGF. All modelling groups are encouraged to check the results for their model.

(b) the PCMDI Metrics Package (PMP, Gleckler et al., 2016) emphasizes a diverse suite of summary statistics to objectively gauge the level of agreement between model simulations and observations across a broad range of space and time scales. It is built on the Python based Ultrascale Visualization Climate Data Analysis Tools (UV-CDAT), a powerful software tool kit that provides cutting-edge data management, diagnostic and visualization capabilities. The PMP is available as open source software on GitHub (https://github.com/PCMDI/pcmdi_metrics).

Since these tools are freely available on GitHub, modelling groups participating in CMIP can additionally make use of these packages. They could choose, for example, to utilize the tools during the model development process in order to identify relative strengths and weaknesses of new model versions also in the context of the performance of other models or they could run the tools locally before publishing the model output to the ESGF. Mechanisms are in place to enable contributions from the broader community. Both tools are designed to readily work across ESGF nodes with the intent of ultimately expediting routine analysis by alleviating the needs for data transfer. We expect the benefits of this activity to become increasingly apparent during the research phase of CMIP6. We encourage the community to consider contributing additional diagnostics and metrics to these CMIP6 evaluation tools. More details on this approach can be found in Eyring et al. (2016b).



Applications for CMIP6 Endorsed MIPs

See https://www.wcrp-climate.org/modelling-wgcm-mip-catalogue/modelling-wgcm-cmip6-endorsed-mips

CMIP5 survey

  • CMIP5 Survey - sent out to representatives of the climate community end of June 2013
  • Synthesis of CMIP5 Survey (August 2013) (Presentation by Veronika Eyring and Ron Stouffer at the Workshop ‘Next Generation Climate Change Experiments Needed to Advance Knowledge and for Assessment of CMIP6’, 5 August 2013, Aspen, CO, USA
  • Synthesis of CMIP5 Survey (October 2013) (Presentation by Veronika Eyring and Ron Stouffer at the WGCM 17th Session, 1-3 October 2013, Victoria, Canada)

Previous iterations on the CMIP6 Design

The CMIP6 design and organization was finalized at the WGCM 18th Session that was held 8-10 October 2014 in Grainau/Garmisch-Partenkirchen (Germany).

A brief summary can be found in the following overview presentation (CMIP6FinalDesign_WGCMMeeting_150116_Sent.pdf) and below. The final CMIP6 Design, possibly with small modifications to the here presented figures and wording, will be published in a GMD Special Issue together with a description of the CMIP6-Endorsed MIPs and the forcing datasets. This Special Issue will open 30 April 2015.

The DECK which will serve as an entry card for CMIP will consist of the following four simulations: (a) AMIP simulation (~1979-2014); (b) Pre-industrial control simulation; (c) 1%/yr CO2 increase, and (d) Abrupt 4xCO2 run. In addition, the CMIP6 Historical Simulation has been added which will serve as the entry card for CMIP6 and as a benchmark for CMIP6-Endorsed MIPs . The historical simulation (1850-2014) will use the specific forcings consistent with CMIP6 which will be finalized on the timescales laid out in slide 10. The CMIP6 Historical Simulation has been introduced in addition to the DECK to better separate CMIP from a specific Phase of CMIP (see slide 4 for illustration and slide 5 for the main criteria for DECK and Historical Phase X). Both DECK and the CMIP6 Historical Simulation should be run for each model configuration used in the subsequent CMIP6-Endorsed MIPs. Future climate change scenarios will be run as part of ScenarioMIP with a Tier 1 that includes three different scenarios, spanning different possible futures.

The criteria for MIP endorsement have been streamlined and agreed at the WGCM 18th session. They now comprise a single set covering MIPs and their experiments. A timeline towards MIP endorsement and beyond has been agreed. Input to the data request will be coordinated by the WGCM Infrastructure Panel.