Coupled Model Intercomparison Project Phase 6 (CMIP6): Experimental Design and Organization Veronika Eyring, Jerry Meehl, Bjorn Stevens, Ron Stouffer, Karl Taylor (CMIP Panel) Sandrine Bony and Cath Senior (WGCM Co-chairs) 18 October 2015 WGCM Meeting, Dubrovnik Please see the CMIP Panel website for additional information and updates: http://www.wcrp-climate.org/index.php/wgcm-cmip/about-cmip Contact for questions: CMIP Panel Chair Veronika Eyring (email: Veronika.Eyring@dlr.de) The final CMIP6 Design, possibly with small modifications to the here presented figures and wording, will be published in a CMIP6 Special Issue together with a description of the CMIP6-Endorsed MIPs and the forcing datasets. This Special Issue will open ~April 2015.

Today’s and Tomorrow’s Agenda Forcings Evaluation activities for CMIP6 Data request Reports by the modelling groups …. Continued by Posters from each of the 21 CMIP6-Endorsed MIPs tomorrow Unique opportunity to have all these people in one room Modelling group representatives MIP co-chairs (1 from each MIP today; possibly more tomorrow) Martin Juckes and WIP co-chairs (Data request) WGCM members

Timeline Forcing Datasets Initial description of each forcing dataset sent to CMIP Panel chair (Forcing Group, 31 January 2015) Initial description reviewed (Model groups, 31 March 2015) Description of forcing datasets in CMIP6 Special Issue (Forcing Group, preferably by 31 December 2015) => now changed to March 2016 Forcing datasets available (Forcing group, see next slide)

1st draft description of forcings Review forcings descriptions Finalize scenario choice, March 2015 (O’Neill, Tebaldi, van Vuuren) CMIP6 Timeline WGCM CMIP6 Design Jan 1 2015 April July Oct 2016 CMIP6 Design Special Issue including forcing description Oct 2016 Jan 1 2017 1st draft description of forcings Review forcings descriptions PI/Historical SLCF emissions (S. Smith) Historical SLCF emissions with uncertainties, seasonality, + (S. Smith) Historical GHG emissions to 2014 (B. Andres) Gridded GDP and population maps etc. (HYDE & IIASA website) = prototype ready Historical land use (G. Hurtt, D. Lawrence) = Pre-industrial ready Historical GHG concentrations (M. Meinshausen) Historical ozone concentrations (M. Hegglin, J.-F. Lamarque) Historical aerosol concentrations (B. Stevens) Solar past and future (K. Matthes, B. Funke) Volcanoes (L. Thomason et al.) Future emissions (IAMs) Gridding & Harmonization past to future (IAMs) Future GHG concentrations (IAMs) Future ozone and aerosol concentrations (M. Hegglin, J.-F Lamarque, B. Stevens) Future harmonized land use dataset (G. Hurtt, D. Lawrence) PI control and idealized model experiments: DECK CMIP6 Historical Simulation ScenarioMIP global model runs Nominal Period of CMIP6 (2015-2020)

Timeline Data Request

CMIP6-Endorsed Model Intercomparison Projects (MIPs) Ongoing Diagnosis, Evaluation, and Characterization of Klima (DECK) Experiments DECK (entry card for CMIP) AMIP simulation (~1979-2014) Pre-industrial control simulation 1%/yr CO2 increase Abrupt 4xCO2 run CMIP6 Historical Simulation (entry card for CMIP6) Historical simulation using CMIP6 forcings (1850-2014) (DECK & CMIP6 Historical Simulation to be run for each model configuration used in the subsequent CMIP6-Endorsed MIPs) Note: The themes in the outer circle of the figure might be slightly revised at the end of the MIP endorsement process

CMIP6-Endorsed MIPs and Model Groups’ Commitments to Participate in each MIP   Long Name of MIP (Short Name of MIP) 1 Aerosols and Chemistry Model Intercomparison Project (AerChemMIP) 2 Coupled Climate Carbon Cycle Model Intercomparison Project (C4MIP) 3 Cloud Feedback Model Intercomparison Project (CFMIP) 4 Detection and Attribution Model Intercomparison Project (DAMIP) 5 Decadal Climate Prediction Project (DCPP) 6 Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP) 7 Geoengineering Model Intercomparison Project (GeoMIP) 8 Global Monsoons Model Intercomparison Project (GMMIP) 9 High Resolution Model Intercomparison Project (HighResMIP) 10 Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) 11 Land Surface, Snow and Soil Moisture MIP (LS3MIP) 12 Land-Use Model Intercomparison Project (LUMIP) 13 Ocean Model Intercomparison Project (OMIP) 14 Paleoclimate Modelling Intercomparison Project (PMIP) 15 Radiative Forcing Model Intercomparison Project (RFMIP) 16 Scenario Model Intercomparison Project (ScenarioMIP) 17 Volcanic Forcings Model Intercomparison Project (VolMIP) 18 Coordinated Regional Climate Downscaling Experiment (CORDEX) 19 Dynamics and Variability of the Stratosphere-Troposphere System (DynVar) 20 Sea-Ice Model Intercomparison Project (SIMIP) 21 Vulnerability, Impacts & Adaptation and Climate Services AB (VIACS AB) VIA AB includes members from the Global Programme of Research on Climate Change Vulnerability, Impacts and Adaptation (PROVIA), the IPCC Task Group on Data and Scenario Support for Impact and Climate Analysis (TGICA), the World Climate Research Programme (WCRP) Working Group on Regional Climate (WGRC), the International Committee On New Integrated Climate change assessment Scenarios (ICONICS), and the Climate Services community

Status and Outlook CMIP6 Status CMIP6 Organization and Design finalized CMIP6 MIP endorsement of April 2015 proposals finalized Timelines in place for forcing datasets CMIP6 Simulation Period (2016-2020) Infrastructure in preparation (including data request) by WGCM Infrastructure Panel (WIP) CMIP6 Participating Model Groups: > 30 using a hierarchy of models CMIP6 Scenarios New scenarios span the same range as the RCPs, but fill critical gaps for intermediate forcing levels and questions for example on short-lived species and land-use. A central goal of CMIP6 is routine evaluation of the models with observations Coordinated by the WGNE / WGCM climate diagnostics and metrics panel in collaboration with the CMIP Panel Workshops/meetings 18-20 October 2015: WGCM-19 (Dubrovnik, Croatia) 20-23 October 2015: WCRP/FP7 EMBRACE Workshop on CMIP5 Model Analysis and Scientific Plans for CMIP6 (Dubrovnik, Croatia) Geosci. Model Dev. Special Issue on CMIP6 (July 2015 - December 2016) Overview of the CMIP6 Design and Organization (Eyring et al., in prep, GMD, 2015) Experimental design from all CMIP6-Endorsed MIPs (submission by 31 March 2016) Description of the CMIP6 forcing data Description of evaluation procedures (including obs4MIPs) and Infrastructure (http://www.earth-system-science-data.net/) and the newly formed   Nature Scientific Data (http://www.nature.com/scientificdata/). The  machinery for QC of data and metadata standards falls under this. These will require a "non-trivial"   amount of work to develop (as promised in the WIP charter!) and may   involve surveys of data providers and users http://www.wcrp-climate.org/index.php/wgcm-cmip/about-cmip 8

CMIP6 Overview Paper Background and motivation for new CMIP structure Overview of Special Issue Description of CMIP DECK experiments with detailed description how Experiment CMIP6 label Experiment Description Forcing methods Start Year End Year Minimum # Years Major purpose Historical AMIP amip Observed SSTs and SICs prescribed CO2 concentration-driven 1979 2014 36 Evaluation Pre-industrial control piControl Coupled atmosphere/ocean pre-industrial control run (concentration driven) CO2 emission- or concentration-driven 1850 n/a 500 Evaluation, unforced variability 1 %/yr CO2 1pctCO2 CO2 prescribed to increase at 1%/yr until concentrations have quadrupled, and then (optionally) extended 160 years with CO2 concentration held constant 140 Climate sensitivity, feedbacks Quadruple CO2 abruptly, then hold fixed abrupt4xCO2 CO2 abruptly quadrupled and then held constant 150 Climate sensitivity, feedbacks, fast responses Past ~1.5 centuries historical Simulation of the recent past 165

CMIP6 Overview Paper Background and motivation for new CMIP structure Overview of Special Issue Description of CMP DECK CMIP standardization, coordination, infrastructure, and documentation functions Overview of CMIP6-Endorsed MIPs   Short name of MIP Long name of MIP Primary Goal in CMIP6 1 AerChemMIP Aerosols and Chemistry Model Intercomparison Project Quantifying forcings, feedbacks and global-to-regional climate response from changes in near term climate forcers (NTCF) emissions (aerosols and ozone precursors) and reactive GHGs concentrations. 2 C4MIP Coupled Climate Carbon Cycle Model Intercomparison Project Understanding and quantifying future (century-scale) changes in land and ocean carbon storage and fluxes. 21 VIACS AB => Please send us 1-2 sentences on the goal of you MIP that you want to see in this table if possible by Friday lunch time

CMIP6 Special Issue in GMD 1 CMIP6 Experimental Design & Organisation Overview 2 AerChemMIP CMIP6-Endorsed MIP 3 C4MIP 4 CFMIP 5 DAMIP 6 DCPP 7 FAFMIP 8 GeoMIP 9 GMMIP 10 HighResMIP 11 ISMIP6 12 LS3MIP 13 LUMIP 14 OMIP 15 PMIP 16 RFMIP 17 ScenarioMIP 18 VolMIP 19 CORDEX* 20 DynVar* 21 SIMIP* 22 VIACS AB* 23 Historical SLCF and GHG Emissions Forcings DECK and Historical Simulation 24 Global Gridded Land-use Forcing Datasets 25 Historical GHG concentrations 26 Ozone and Stratospheric Water Vapor Concentrations 27 Aerosol Concentrations 28 Solar forcing 29 Stratospheric Aerosol Data Set 30 Future Emissions Should be described in ScenarioMIP paper? 31 AMIP SSTs and Sea Ice Datasets 32 WGCM Infrastructure Panel (WIP) Infrastructure 33 CMIP6 Data Request 34 WGNE/WGCM climate model diagnostics and metrics panel Model Evaluation 35 WDAC Task Team on Observations for Model Evaluation (http://www.earth-system-science-data.net/) and the newly formed   Nature Scientific Data (http://www.nature.com/scientificdata/). The  machinery for QC of data and metadata standards falls under this. These will require a "non-trivial"   amount of work to develop (as promised in the WIP charter!) and may   involve surveys of data providers and users 11

MIP Papers (1) We are hoping that the GMD paper describing your MIP addresses all points of the application template and links clearly to one or more of the CMIP6 scientific questions and the WCRP Grand Challenges. that your paper covers the experimental design and scientific justification of each of the experiments in detail for Tier 1 (and possibly beyond), so that the groups actually find all the necessary information on why and how to run the experiment in your paper. Detailed technical instructions could be moved to supporting material if required. Your paper should also clearly make links from your experiments to the DECK and the CMIP6 Historical Simulation which form the glue of our CMIP6 multi-model, multi- experiment exercise.   It is expected that the MIPs also include a strong analysis plan to fully justify the resources used to produce the various requested variables. Further if the analysis plan is to compare model results to observations, please indicate what observations will be used, and whether the comparison entails any particular requirement for the simulations or outputs. The forcings for the DECK and the CMIP6 Historical Simulations will be described as well in the CMIP6 Special Issue. Should you require additional forcings as part of your MIP experiments these would need to be created by your MIP and described in your GMD contribution.

MIP Papers (2) We have chosen an open-discussion journal for the review process to allow for yet another entry point for the community to broadly review the specific design. Should you receive comments on specific experiments that your author team finds worth considering, or receive otherwise important information, individual experiments can still change or be added. If this results in a change to the Tier 1 experiments, this requires CMIP Panel approval. In addition, the modelling groups that participate in your MIP need to be informed and confirm that they would still run all of the Tier 1 experiments for a specific science question. If this applies to Tier 2 or 3 experiments, the MIP endorsement criteria that relate to these experiments need to be fulfilled, in particular that the experiments are well-defined, useful in a multi-model context and don’t overlap with other CMIP6 experiments. All authors for GMD are expected to suggest 5 reviewers for each manuscript which the editor may, at their own discretion, use as a guide for inviting reviewers. For our GMD special issue on CMIP6, the GMD chief-executive editor requests that the authors find at least one reviewer from their five suggestions who agrees beforehand to review the manuscript. The authors should state this person's name in the message to the editor. In order to get the CMIP6 design well-described in time for the modelling groups to prepare and start the runs, the deadline for the submission of the papers for the now endorsed MIPs is 31 March 2016.