@article{fdi:010080619,
  title = {{E}astern {A}tlantic deep-water circulation and carbon storage inferred from neodymium and carbon isotopic compositions over the past 1.1 million years},
  author = {{T}achikawa, {K}. and {R}apuc, {W}. and {V}idal, {L}. and {D}ubois-{D}auphin, {Q}. and {W}esterhold, {T}. and {G}uihou, {A}. and {B}ickert, {T}. and {P}erez-{A}sensio, {J}. {N}. and {D}eschamps, {P}ierre and {S}konieczny, {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {M}id-{P}leistocene transition ({MPT}; 1200 to 800 thousand years, kyr) is marked by the shift from 41-kyr to 100-kyr interglacial-glacial cyclicity without substantial change in the astronomical forcing. {T}his change in climate response relied on internal feedback processes including interaction between ice sheet/sea ice, ocean circulation and the carbon cycle. {I}t was suggested that a major perturbation of global oceanic carbon chemistry occurred at around 900 ka ({M}arine {I}sotope {S}tage, {MIS}, 24-22) although the mechanism responsible for the change is still to be elucidated. {T}o investigate the link between the {A}tlantic {M}eridional {O}verturning {C}irculation ({AMOC}) and oceanic carbon storage for the past 1100 kyr, we combined neodymium isotopic composition ({N}d-143/{N}d-144 or epsilon({N}d)) recorded in foraminiferal authigenic fractions with epibenthic foraminiferal delta {C}-13 and delta {O}-13 from two cores in the {N}orth- and {S}outh-east {A}tlantic {O}cean. {G}lacial/interglacial e{N}d amplitude is smaller before the 900-ka event than after the event. {T}he 900-ka event is marked by increase in seawater epsilon({N}d) at both sites. {T}hese observations are consistent with previous studies, suggesting basin-wide epsilon({N}d) changes. {C}ombined with existing data, these new results reveal a persistent meridional gradient of seawater epsilon({N}d) in the {A}tlantic {O}cean over the past 1100 kyr. {B}y comparing the reconstructions with numerical modelling results, we propose that weaker {AMOC} and changes in {N}d sources to the {N}orth {A}tlantic were the main reasons for the observed e{N}d shift at the 900-ka event in relation to the evolution of the {N}orthern hemisphere cryosphere. {T}he influence of enhanced {S}outhern {O}cean overturning circulation on e{N}d values was estimated to be minor. {S}eawater epsilon({N}d) and benthic delta {C}-13 relationship for the whole study period indicates the presence of carbon-rich glacial deep water (>3000 m) in the {N}orth and the {S}outh {A}tlantic, in particular at {MIS} 22 and 24. {T}his suggests that, in addition to weaker {AMOC}, reduction of deep-water ventilation and/or air-sea exchange in the {S}outhern {O}cean could have been responsible for the observed low benthic delta {C}-13 values. {T}ogether with increased biological productivity due to iron fertilization in the {S}outhern {O}cean, the physical process significantly contributed to the deep {A}tlantic carbon storage during the 900-ka event and the subsequent glacial periods.},
  keywords = {{M}id-{P}leistocene transition ; {N}d isotopic composition ; {B}enthic foraminiferal delta {C}-13 ; {O}cean circulation ; {A}tlantic ocean ; {ATLANTIQUE}},
  booktitle = {},
  journal = {{Q}uaternary {S}cience {R}eviews},
  volume = {252},
  numero = {},
  pages = {106752 [14 p.]},
  ISSN = {0277-3791},
  year = {2021},
  DOI = {10.1016/j.quascirev.2020.106752},
  URL = {https://www.documentation.ird.fr/hor/fdi:010080619},
}