Ortega P. auteur aut IRD Mignot Juliette auteur aut IRD Swingedouw D. auteur aut IRD Sevellec F. auteur aut IRD Guilyardi E. auteur aut IRD text journalArticle eng text/pdf born digital access Understanding the preferential timescales of variability in the North Atlantic, usually associated with the Atlantic meridional overturning circulation (AMOC), is essential for the prospects for decadal prediction. However, the wide variety of mechanisms proposed from the analysis of climate simulations, potentially dependent on the models themselves, has stimulated the debate of which processes take place in reality. One mechanism receiving increasing attention, identified both in idealized models and observations, is a westward propagation of subsurface buoyancy anomalies that impact the AMOC through a basin-scale intensification of the zonal density gradient, enhancing the northward transport via thermal wind balance. In this study, we revisit a control simulation from the Institut Pierre-Simon Laplace Coupled Model 5A (IPSL-CM5A), characterized by a strong AMOC periodicity at 20 years, previously explained by an upper ocean atmosphere sea ice coupled mode driving convection activity south of Iceland. Our study shows that this mechanism interacts constructively with the basin-wide propagation in the subsurface. This constructive feedback may explain why bi-decadal variability is so intense in this coupled model as compared to others. specialized ATLANTIQUE NORD 032 020 137 A 237-249 2015 0079-6611 https://www.documentation.ird.fr/hor/fdi:010065359 10.1016/j.pocean.2015.06.009 0079-6611 [F B010065359] https://www.documentation.ird.fr/hor/fdi:010065359 https://www.documentation.ird.fr/intranet/publi/2015/10/010065359.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2015-11-06 2017-08-23 fdi:010065359 fre