@article{fdi:010072411,
  title = {{I}ntrinsic and atmospherically forced variability of the {AMOC} : insights from a large-ensemble ocean hindcast},
  author = {{L}eroux, {S}. and {P}enduff, {T}. and {B}essieres, {L}. and {M}olines, {J}. {M}. and {B}rankart, {J}. {M}. and {S}{\'e}razin, {G}uillaume and {B}arnier, {B}. and {T}erray, {L}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his study investigates the origin and features of interannual-decadal {A}tlantic meridional overturning circulation ({AMOC}) variability from several ocean simulations, including a large (50 member) ensemble of global, eddy-permitting (1/4 degrees) ocean-sea ice hindcasts. {A}fter an initial stochastic perturbation, each member is driven by the same realistic atmospheric forcing over 1960-2015. {T}he magnitude, spatiotemporal scales, and patterns of both the atmospherically forced and intrinsic-chaotic interannual {AMOC} variability are then characterized from the ensemble mean and ensemble spread, respectively. {T}he analysis of the ensemble-mean variability shows that the {AMOC} fluctuations north of 40 degrees {N} are largely driven by the atmospheric variability, which forces meridionally coherent fluctuations reaching decadal time scales. {T}he amplitude of the intrinsic interannual {AMOC} variability never exceeds the atmospherically forced contribution in the {A}tlantic basin, but it reaches up to 100% of the latter around 35 degrees {S} and 60% in the {N}orthern {H}emisphere midlatitudes. {T}he intrinsic {AMOC} variability exhibits a large-scale meridional coherence, especially south of 25 degrees {N}. {A}n {EOF} analysis over the basin shows two large-scale leading modes that together explain 60% of the interannual intrinsic variability. {T}he first mode is likely excited by intrinsic oceanic processes at the southern end of the basin and affects latitudes up to 40 degrees {N}; the second mode is mostly restricted to, and excited within, the {N}orthern {H}emisphere midlatitudes. {T}hese features of the intrinsic, chaotic variability (intensity, patterns, and random phase) are barely sensitive to the atmospheric evolution, and they strongly resemble the "pure intrinsic' interannual {AMOC} variability that emerges in climatological simulations under repeated seasonal-cycle forcing. {T}hese results raise questions about the attribution of observed and simulated {AMOC} signals and about the possible impact of intrinsic signals on the atmosphere.},
  keywords = {{ATLANTIQUE}},
  booktitle = {},
  journal = {{J}ournal of {C}limate},
  volume = {31},
  numero = {3},
  pages = {1183--1203},
  ISSN = {0894-8755},
  year = {2018},
  DOI = {10.1175/jcli-d-17-0168.1},
  URL = {https://www.documentation.ird.fr/hor/fdi:010072411},
}