Climate Data Request Task Team

Co-leads: Martin Juckes, STFC and Chloe Mackallah, CSIRO

This task team will focus on how the CMIP data request should define the quantities from CMIP7 simulations that should be archived, both quantities of general interest needed from the majority of CMIP7 model intercomparsion projects (MIPs) and more specialised quantities only of interest to individual/small numbers of MIPs.

On this page:


The complexity of the data request has increased from the early days of model intercomparisons, as has the data volume. The CMIP6 request defined distinct sets of highly tailored variables to be saved from each of the more than 200 experiments. Following review of the CMIP6 experience, some rationalisation has been agreed and there will be more consistency of the request between related experiments, while allowing enough flexibility to avoid archiving redundant data. Further details in Juckes et al. (2020).

It has also been suggested that the model used for defining the priority of variables should be simplified, with greater use of common template variable lists for experiments and a more cautious approach to applying top priority to data requirements.

Aim & Objectives

The aim of this TT is to ensure that a consolidated final request is ready when modelling centres need to start CMIP7 simulations.

The objectives are to:

  • Oversee the creation of the CMIP7 Data Request which should provide participating modelling centres with full details of CMIP7 output requirements from participating science teams.
  • Ensure that the CMIP7 output requirements accurately reflect both the ambition of the science teams, the constraints of the data managing services, and the resources of the modelling centres.

A number of strategic requirements have been identified for the next version of the data request (see IS-ENES3 Milestone M10.2 report). These include:

  • maintaining a similar structure, to minimise effort needed to interpret the Request
  • clearer links with externals sources of information such as the controlled vocabularies, allowing for alternate representations such as normalised databases, and;
  • the ability to clearly understand changes to the content of the Data Request as it is updated.


Climate Data Request Task Team members

James Anstey 2024- (member since 2022) Co-lead Environment Canada Canada
Martin Juckes 2022- Co-lead STFC UK
Chloe Mackallah 2022- Co-lead CSIRO Australia
Tommi Bergman 2022- Member FMI Finland
Léa Braschi 2022- Member CBCL Canada
Pierre-Antoine Bretonnière 2022- Member BSC-CNS Spain
Antonio S. Cofiño 2022- Member IFCA-CSIC Spain
Michio Kawamiya 2022- Member JAMSTEC Japan
Hyungjun Kim 2022- Member KAIST CEE Republic of Korea
Charles Koven 2022- Member Berkeley Lab USA
Hsin-Chien Liang 2022- Member Sinica Taiwan
Tomas Lovato 2022- Member CMCC Italy
Marie-Pierre Moine 2022- Member CERFACS France
Sandeep Narayanasetti 2022- Member IITM India
Alison Pamment 2022- Member STFC UK
Charlotte Pascoe 2022- Member STFC UK
Gaëlle Rigoudy 2022- Member Météo France France
Martin Schupfner 2022- Member DKRZ Germany
Klaus Zimmermann 2022- Member SMHI Sweden


Harmonised thematic variables

The task team are working with community representatives to devise a controlled list of high priority variables that facilitate the majority of user needs. Papers across the identified themes will define a collection of harmonised variables to support the high impact analysis of climate model output, and provide a consistent and robust set of parameters on which to build the CMIP7 archive. Each will be a collaboration between the CMIP Data Request Task Team and the MIPs and communities relevant to each theme.

Read about the CMIP7 Data Request process and progress on the dedicated webpage.

MIP drop-in sessions – CMIP AR7 Fast Track Data Request (June 2024)

These CMIP AR6 Fast Track Data Request MIP drop-in sessions were held across two time slots: Wednesday 5 June 15.00-16:00 UTC and Thursday 6 June at 08:00-09:00 UTC to support equitable global participation. 

Data Request Task Team members presented the process for MIP engagement in development of the harmonised variable list for the AR7 Fast Track experiments. This was followed in each session by an interactive question and answer session. The sessions set out the current engagement process through the author teams and outlined the forthcoming consultation and survey for MIPs and modelling centres/groups.

Variables drop-in session and report (June 2023)

A series of regular drop-in sessions was launched in early 2023, facilitated by the CMIP International Project Office (CMIP IPO), to cover key aspects of CMIP7 design and development and promote community feedback to the CMIP governance and Task Teams. 

The first CMIP Variables drop-in sessions were held on 1 June 2023 and 8 June 2023 across two timeslots (16:00 UTC and 05:00 UTC respectively) to support equitable global participation. Each session was chaired by either CMIP Panel co-chair John Dunne (1st June) or CMIP Panel member Julie Arblaster (8th June) and led by one of the Data Request Task Team co-leads, Martin Juckes (CEDA/STFC, UK) or Chloe Mackallah (CSIRO, AU). During the sessions, attendees were asked to provide feedback on their evolving variable needs (in terms of complexity, volume, and timing) with respect to increasingly complex models. There were also discussions on meeting the demands of downstream users, and the capacity of models and workflows to support those needs. These sessions aimed to facilitate community discussion on variable requirements as planning for CMIP7 gets underway. 

Find the Variables drop-in session report by following this link (opens in a new tab).

Membership call

Open call for members closed in October 2022 – call text available here.

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