Mercier, HerléDesbruyères, DamienLherminier, PascaleVelo, AntónCarracedo, LidiaF. Pérez, FizMorente Fontela, Marcos2024-09-032024-09-032024-06-141812-0792http://hdl.handle.net/10400.1/25828The Atlantic Meridional Overturning Circulation (AMOC) is a key component of the Earth's climate. However, there are few long time series of observations of the AMOC, and the study of the mechanisms driving its variability depends mainly on numerical simulations. Here, we use four ocean circulation estimates produced by different data-driven approaches of increasing complexity to analyse the seasonal to decadal variability of the subpolar AMOC across the Greenland-Portugal OVIDE (Observatoire de la Variabilit & eacute; Interannuelle & agrave; D & Eacute;cennale) line since 1993. We decompose the MOC strength variability into a velocity-driven component due to circulation changes and a volume-driven component due to changes in the depth of the overturning maximum isopycnal. We show that the variance of the time series is dominated by seasonal variability, which is due to both seasonal variability in the volume of the AMOC limbs (linked to the seasonal cycle of density in the East Greenland Current) and to seasonal variability in the transport of the Eastern Boundary Current. The decadal variability of the subpolar AMOC is mainly caused by changes in velocity, which after the mid-2000s are partly offset by changes in the volume of the AMOC limbs.engjournal article10.5194/os-20-779-2024