Coupled climate response to Atlantic Multidecadal Variability in a multi-model multi-resolution ensemble

• Published in: Climate Dynamics
• Main Authors: Hodson, Daniel L. R., Bretonnière, Pierre-Antoine, Cassou, Christophe, Davini, Paolo, Klingaman, Nicholas P., Ruprich-Robert, Yohan
• Other Authors: Barcelona Supercomputing Center
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2022
• Subjects: Àrees temàtiques de la UPC::Enginyeria agroalimentària::Ciències de la terra i de la vida::Climatologia i meteorologia; Sea surface microlayer; Air-sea interaction; AMV; Atlantic multidecadal variability; AMO; Atlantic multidecadal oscillation; High resolution; Decadal variability; Canvis climàtics > Models matemàtics; Simulació per ordinador; Pacific; Lopez; Gomez; Cierva; Seddon; North Atlantic
• Online Access: http://hdl.handle.net/2117/363393; https://doi.org/10.1007/s00382-022-06157-9

North Atlantic sea surface temperatures (SSTs) underwent pronounced multidecadal variability during the twentieth and early twenty-first century. We examine the impacts of this Atlantic Multidecadal Variability (AMV), also referred to as the Atlantic Multidecadal Oscillation (AMO), on climate in an ensemble of five coupled climate models at both low and high spatial resolution. We use a SST nudging scheme specified by the Coupled Model Intercomparision Project’s Decadal Climate Prediction Project Component C (CMIP6 DCPP-C) to impose a persistent positive/negative phase of the AMV in the North Atlantic in coupled model simulations; SSTs are free to evolve outside this region. The large-scale seasonal mean response to the positive AMV involves widespread warming over Eurasia and the Americas, with a pattern of cooling over the Pacific Ocean similar to the Pacific Decadal Oscillation (PDO), together with a northward displacement of the inter-tropical convergence zone (ITCZ). The accompanying changes in global atmospheric circulation lead to widespread changes in precipitation. We use Analysis of Variance (ANOVA) to demonstrate that this large-scale climate response is accompanied by significant differences between models in how they respond to the common AMV forcing, particularly in the tropics. These differences may arise from variations in North Atlantic air-sea heat fluxes between models despite a common North Atlantic SST forcing pattern. We cannot detect a widespread effect of increased model horizontal resolution in this climate response, with the exception of the ITCZ, which shifts further northwards in the positive phase of the AMV in the higher resolution configurations. The Authors would like to acknowledge the use of the UKRI funded JASMIN data analysis facility which was essential to the analysis and storage of PRIMAVERA project data. Ongoing curation of project data has been supported by the IS-ENES3 project that has received funding from the European Union’ Horizon 2020 research and innovation programme under Grant Agreement No. 824084. Authors DH, PM, JS, PD, YRR, CDR acknowledge funding from the PRIMAVERA project (www.primavera-h2020.eu), funded by the European Union’s Horizon 2020 programme under Grant Agreement 641727. PM was supported by U.K.–China Research and Innovation Partnership Fund through the Met Office Climate Science for Service Partnership (CSSP) China as part of the Newton Fund. PD thanks ECMWF for providing computing time in the framework of the special projects SPITDAVI. YRR was funded by the European Union’s Horizon 2020 Research and Inovation Programme in the framework of the Marie Skłodowska-Curie grant INADEC (Grant Agreement 80015400). Author DH would like to thank Nick Klingaman and Linda Hirons for their extensive help with the MetUM-GOML model. This article was written with support (DH) from National Environmental Research Council (NERC) national capability grant for the North Atlantic Climate System: Integrated study (ACSIS) program (Grants NE/N018001/1, NE/N018044/1, NE/N018028/1, and NE/N018052/1). MMR is supported by a Juan de la Cierva Incorporacion research contract of MICINN (Spain). The authors wish to acknowledge use of the Ferret program for analysis and graphics in this paper. Ferret is a product of NOAA’s Pacific Marine Environmental Laboratory. (Information is available at http://ferret.pmel.noaa.gov/Ferret/) and also the CF-python analysis package http://ncas-cms.github.io/cf-python/. Assembly of MetUM-GOML and development of MC-KPP was supported by the National Centre for Atmospheric Science and led by Dr. Nicholas Klingaman. The authors would also like to thank the three anonymous reviewers whose comments contributed to a much improved final manuscript. Peer Reviewed "Article signat per 17 autors/es: Daniel L. R. Hodson, Pierre-Antoine Bretonnière, Christophe Cassou, Paolo Davini, Nicholas P. Klingaman, Katja Lohmann, Jorge Lopez-Parages, Marta Martín-Rey, Marie-Pierre Moine, Paul-Arthur Monerie, Dian A. Putrasahan, Christopher D. Roberts, Jon Robson, Yohan Ruprich-Robert, Emilia Sanchez-Gomez, Jon Seddon & Retish Senan" Postprint (published version)