The intensification of northern component deepwater formation during the mid‐Pleistocene climate transition

Poirier, Robert K.; Billups, Katharina

doi:10.1002/2014pa002661

Cited by 35 publications

(44 citation statements)

References 89 publications

(169 reference statements)

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“…The similarity between the benthic foraminiferal d 18 O and d 13 C trends in our downcore records ( Fig. 1A) indicates a close relationship between these "climate" and "carbon cycle" signals, which has been described previously (e.g., Raymo et al, 1990Raymo et al, , 1997Poirier and Billups, 2014). We use our metal/Ca records to explore potential mechanisms behind this tight coupling.…”

Section: Introductionsupporting

confidence: 75%

Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition

Lear

Billups

Rickaby

et al. 2016

Geology

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The ~100 k.y. cyclicity of the late Pleistocene ice ages started during the mid-Pleistocene transition (MPT), as ice sheets became larger and persisted for longer. The climate system feedbacks responsible for introducing this nonlinear ice sheet response to orbital variations in insolation remain uncertain. Here we present benthic foraminiferal stable isotope (d 18 O, d 13 C) and trace metal records (Cd/Ca, B/Ca, U/Ca) from Deep Sea Drilling Project Site 607 in the North Atlantic. During the onset of the MPT, glacial-interglacial changes in d 13 C values are associated with changes in nutrient content and carbonate saturation state, consistent with a change in water mass at our site from a nutrient-poor northern source during interglacial intervals to a nutrient-rich, corrosive southern source during glacial intervals. The respired carbon content of glacial Atlantic deep water increased across the MPT. Increased dominance of corrosive bottom waters during glacial intervals would have raised mean ocean alkalinity and lowered atmospheric pCO 2 . The amplitude of glacial-interglacial changes in d 13 C increased across the MPT, but this was not mirrored by changes in nutrient content.We interpret this in terms of air-sea CO 2 exchange effects, which changed the d 13 C signature of dissolved inorganic carbon in the deep water mass source regions. Increased sea ice cover or ocean stratification during glacial times may have reduced CO 2 outgassing in the Southern Ocean, providing an additional mechanism for reducing glacial atmospheric pCO 2 . Conversely, following the establishment of the ~100 k.y. glacial cycles, d 13 C of interglacial northern-sourced waters increased, perhaps reflecting reduced invasion of CO 2 into the North Atlantic following the MPT.

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Section: Introductionsupporting

confidence: 75%

Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition

Lear

Billups

Rickaby

et al. 2016

Geology

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“…This time is interesting as the midpoint contains a particularly cold interglacial interval, MIS 23 (~900 Ka) as evidenced by relatively high benthic foraminiferal δ 18 O values (e.g., Lisiecki & Raymo, ) and minima in North Atlantic sea surface temperatures (McClymont et al, ). Various proxies from the Atlantic Ocean (benthic foraminiferal δ 13 C values, CaCO 3 content, and Nd isotopes) agree that thermohaline circulation was relatively weak during this time (e.g., Pena & Goldstein, ; Poirier & Billups, ; Raymo et al, ; Schmieder et al, ). Pena and Goldstein () go as far as referring to this event as a “thermohaline crisis” as they saw a lack of North Atlantic‐sourced waters reaching the Southern Ocean.…”

Section: Introductionmentioning

confidence: 91%

“…However, according to these studies a stronger Gulf Stream would place Site 1058 gyreward of the boundary current and hence optimize G. truncatulinoides (sinistral) abundances rather than shoreward where dextral morphotypes dominate. As there is ample evidence that thermohaline circulation was relatively strong during peak MIS 21 (e.g., Poirier & Billups, 2014, and references therein), we would think that the Gulf Stream, which is an integral part of the meridional overturning circulation (e.g., Rahmstorf, 2002), was relatively strong as well, at least as strong as today. It may be that the absence of the sinistral morphotype during MIS 21 is an early response to the factors responsible for the general lack of this morphotype after MIS 21 at all the other sites, a phenomenon discussed next.…”

Section: 1029/2018pa003502mentioning

confidence: 99%

North Atlantic Upper‐Ocean Hydrography During the Mid‐Pleistocene Transition Evidenced by Globorotalia truncatulinoides Coiling Ratios

Kaiser

Caldwell

Billups

2019

Paleoceanog and Paleoclimatol

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We use the coiling direction of planktic foraminifer Globorotalia truncatulinoides from four sites in the North Atlantic Ocean to assess spatial changes in upper‐ocean hydrography during the mid‐Pleistocene climate transition. Core top sediments indicate that the left‐coiling (sinistral) variety dominates regions characterized by a deep permanent thermocline as is characteristic of the subtropical gyre (Ocean Drilling Program Sites 1058 and Deep Sea Drilling Project Site 607) while right‐coiling (dextral) tests dominate the tropical (Ocean Drilling Program Site 925) and subpolar site (Deep Sea Drilling Project Site 552). We observe pronounced changes in the dominant coiling direction at the three subtropical to subpolar sites during the first of the more extreme glacial to interglacial transitions of the mid‐Pleistocene climate transition, Marine Isotope Stages (MISs) 22 to 21. We interpret these observations to reflect an increase in poleward warm water advection. The time interval between MIS 21 and MIS 15 is marked by a pronounced absence of sinistral tests. Because G. truncatulinoides (sinistral) is a deep dwelling species, their absence may be related to a decrease in dissolved oxygen during warm interglacial intervals. At the tropical site, precessional‐scale variations dominate changes in the coiling direction until midpoint interglacial MIS 23. Occurrences in the sinistral variety at this locale must be linked to cross‐equatorial water transport in the North Brazil Current, and precessional‐scale variations provide evidence for the sensitivity of the tropical regions to precessional forcing, at least until MIS 23 when this morphotype disappears in agreement with observation at other sites in the Atlantic Ocean.

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“…The late Pleistocene (<0.9 Ma) Atlantic Ocean experienced glacial suppression of NADW at its greatest for the entire PlioPleistocene (Hodell et al, 2001;Raymo et al, 1997;Venz and Hodell, 2002), while interglacial NADW remained strong, possibly even enhancing across the EMPT (Poirier and Billups, 2014). The associated changes in AMOC during the late Pleistocene are considered central to producing the severe~100 kyr glacials cycles, through reductions in northward heat transport and enhanced storage of CO 2 at depth (Imbrie et al, 1993).…”

Section: The Early-middle Pleistocene Transitionmentioning

confidence: 99%

The Plio-Pleistocene development of Atlantic deep-water circulation and its influence on climate trends

Bell

Jung

Kroon

2015

Quaternary Science Reviews

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The intensification of northern component deepwater formation during the mid‐Pleistocene climate transition

Cited by 35 publications

References 89 publications

Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition

Breathing more deeply: Deep ocean carbon storage during the mid-Pleistocene climate transition

North Atlantic Upper‐Ocean Hydrography During the Mid‐Pleistocene Transition Evidenced by Globorotalia truncatulinoides Coiling Ratios

The Plio-Pleistocene development of Atlantic deep-water circulation and its influence on climate trends

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