Attribution of multi-annual to decadal changes in the climate system: The Large Ensemble Single Forcing Model Intercomparison Project (LESFMIP)

• DOI: 10.3389/fclim.2022.955414
• Publication Date: 2022-09-16T05:55:46Z
• Authors: Doug M. Smith; Nathan P. Gillett; Isla R. Simpson; Panos J. Athanasi...; Johanna Baehr; Ingo Bethke; Tarkan A. Bilge; Rémy Bonnet; Olivier Boucher; Kirsten L. Findell; Guillaume Gastineau; Silvio Gualdi; Leon Hermanson; L. Ruby Leung; Juliette Mignot; Wolfgang A. Müller; Scott Osprey; Odd Helge Otterå; Geeta G. Persad; Adam A. Scaife; Gavin A. Schmidt; Hideo Shiogama; Rowan T. Sutton; Didier Swingedouw; Shuting Yang; Tianjun Zhou; Tilo Ziehn
• Keywords: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; model; 550; large ensembles; Lighthouse Activity; attribution; 551; 01 natural sciences; [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; intercomparison; external forcings; Environmental sciences; decadal climate; model intercomparison; 13. Climate action; GE1-350; 0105 earth and related environmental sciences

Multi-annual to decadal changes in climate are accompanied by changes in extreme events that cause major impacts on society and severe challenges for adaptation. Early warnings of such changes are now potentially possible through operational decadal predictions. However, improved understanding of the causes of regional changes in climate on these timescales is needed both to attribute recent events and to gain further confidence in forecasts. Here we document the Large Ensemble Single Forcing Model Intercomparison Project that will address this need through coordinated model experiments enabling the impacts of different external drivers to be isolated. We highlight the need to account for model errors and propose an attribution approach that exploits differences between models to diagnose the real-world situation and overcomes potential errors in atmospheric circulation changes. The experiments and analysis proposed here will provide substantial improvements to our ability to understand near-term changes in climate and will support the World Climate Research Program Lighthouse Activity on Explaining and Predicting Earth System Change.