- University of Vienna Austria
- Canadian Centre for Climate Modelling and Analysis Canada
- University of Toronto Canada
- Met Office United Kingdom
- Universität Hamburg Germany
- Parthenope University of Naples Italy
- Ewha Womans University Korea (Republic of)
- National Centre for Atmospheric Science United Kingdom
- Met Office Hadley Centre United Kingdom
- Barcelona Supercomputing Center Spain
- University of Oxford and National Centre for Atmospheric Science
- BARCELONA SUPERCOMPUTING CENTER - CENTRO NACIONAL DE SUPERCOMPUTACION Spain
- Meteorological Research Institute Japan
- Japan Agency for Marine-Earth Science and Technology Japan
- National Center for Atmospheric Research, University Corporation for Antmospheric Research, Library United States
- University Corporation for Atmospheric Research United States
- Universitätszahnklinik Wien Austria
- Japan Agency for Marine-Earth Science and Technology, Center for Deep Earth Exploration Japan
- University of Oxford United Kingdom
- Northwest Research Associates United States
- Japan Agency for Marine Earth Science an Japan
- Met Office United Kingdom
- Universität Wien, University Library Austria
- National Center for Atmospheric Research United States
- Karlsruher Institut für Technologie, Institut für Nukleare Entsorgung Germany
- University of Hamburg, Herbarium Hamburgense Germany
- Laboratoire de Météorologie Dynamique France
- Japan Agency for Marine-Earth Science and Technology, Institute for Marine-Earth Exploration and Engineering Japan
- Universitat Hamburg, Hamburg, Germany Germany
- Univeristät Wien Austria
- THE GOVERNING COUNCIL OF THE UNIVERSITY OF TORONTO Canada
- European Centre for Medium-Range Weather Forecasts United Kingdom
- Karlsruhe Institute of Technology Germany
- Yonsei University Korea (Republic of)
- University of Exeter United Kingdom
- EDUCATIONAL FOUNDATION YONSEI UNIVERSITY Korea (Republic of)
- Karlsruhe Institute of Technology (KIT) Germany
- JAPAN AGENCY FOR MARINE-EARTH SCIENCE AND TECHNOLOGY
- Karlsruher Institut für Technologie, Institut für Kernphysik Germany
- National Center for Atmospheric Research | University Corporation for Atmospheric Research United States
- Università degli Studi Napoli Parthenope Italy
- National Center for Atmospheric Research (NCAR), Boulder, CO, USA United States
The Stratosphere–troposphere Processes And their Role in Climate (SPARC) Quasi-Biennial Oscillation initiative (QBOi) aims to improve the fidelity of tropical stratospheric variability in general circulation and Earth system models by conducting coordinated numerical experiments and analysis. In the equatorial stratosphere, the QBO is the most conspicuous mode of variability. Five coordinated experiments have therefore been designed to (i) evaluate and compare the verisimilitude of modelled QBOs under present-day conditions, (ii) identify robustness (or alternatively the spread and uncertainty) in the simulated QBO response to commonly imposed changes in model climate forcings (e.g. a doubling of CO2 amounts), and (iii) examine model dependence of QBO predictability. This paper documents these experiments and the recommended output diagnostics. The rationale behind the experimental design and choice of diagnostics is presented. To facilitate scientific interpretation of the results in other planned QBOi studies, consistent descriptions of the models performing each experiment set are given, with those aspects particularly relevant for simulating the QBO tabulated for easy comparison.