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Strength and geometry of the glacial Atlantic Meridional Overturning Circulation

Nature Geoscience volume 5, pages 813–816 (2012)Cite this article

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Abstract

The strength and geometry of the Atlantic meridional overturning circulation is tightly coupled to climate on glacial–interglacial and millennial timescales1, but has proved difficult to reconstruct, particularly for the Last Glacial Maximum2. Today, the return flow from the northern North Atlantic to lower latitudes associated with the Atlantic meridional overturning circulation reaches down to approximately 4,000 m. In contrast, during the Last Glacial Maximum this return flow is thought to have occurred primarily at shallower depths. Measurements of sedimentary 231Pa/230Th have been used to reconstruct the strength of circulation in the North Atlantic Ocean3,4, but the effects of biogenic silica on 231Pa/230Th-based estimates remain controversial5. Here we use measurements of 231Pa/230Th ratios and biogenic silica in Holocene-aged Atlantic sediments and simulations with a two-dimensional scavenging model to demonstrate that the geometry and strength of the Atlantic meridional overturning circulation are the primary controls of 231Pa/230Th ratios in modern Atlantic sediments. For the glacial maximum, a simulation of Atlantic overturning with a shallow, but vigorous circulation and bulk water transport at around 2,000 m depth best matched observed glacial Atlantic 231Pa/230Th values. We estimate that the transport of intermediate water during the Last Glacial Maximum was at least as strong as deep water transport today.

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Figure 1: 231Pa/230Th versus water depth.
Figure 2: 231Pa/230 Th versus preserved opal flux.
Figure 3: Correlation between 231Pa/230Th and model outputs from grid cells closest to core locations.
Figure 4: Fit between observations and model outputs generated with the optimal LGM model geometry with varying Glacial North Atlantic Intermediate Water (GNAIW) and AABW strengths.

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References

  1. Rahmstorf, S. Ocean circulation and climate during the past 120,000 years. Nature 419, 207–214 (2002).

    Article  Google Scholar 

  2. Lynch-Stieglitz, J. et al. Atlantic Meridional Overturning Circulation during the Last Glacial Maximum. Science 316, 66–69 (2007).

    Article  Google Scholar 

  3. Marchal, O., Francois, R., Stocker, T. & Joos, F. Ocean thermohaline circulation and sedimentary 231Pa/230Th ratio. Paleoceanography 15, PA000496 (2000).

    Article  Google Scholar 

  4. Yu, E., Francois, R. & Bacon, M. Similar rates of modern and last-glacial ocean thermohaline circulation inferred from radiochemical data. Nature 379, 689–694 (1996).

    Article  Google Scholar 

  5. Keigwin, D. & Boyle, E. Did North Atlantic Overturning halt 17,000 years ago? Paleoceanography 23, PA1101 (2008).

    Article  Google Scholar 

  6. Curry, W. & Oppo, D. Glacial water mass geometry and the distribution of δ13C of CO2 in the western Atlantic Ocean. Paleoceanography 20, PA1017 (2005).

    Article  Google Scholar 

  7. Boyle, E. & Keigwin, L. North Atlantic thermohaline circulation during the past 20,000 years linked to high-latitude surface temperature. Nature 330, 35–40 (1987).

    Article  Google Scholar 

  8. Marchitto, T. & Broecker, W. Deep watermass geometry in the glacial Atlantic ocean: a review of constraints from the paleonutrient proxy Cd/Ca. Geochem. Geophys. Geosyst. 7, Q12003 (2006).

    Google Scholar 

  9. Burke, A., Marchal, O., Bradtmiller, L., McManus, J. & François, R. Application of an inverse method to interpret 231Pa/230Th observations from marine sediments. Paleoceanography 26, PA1212 (2011).

    Article  Google Scholar 

  10. Kitoh, A., Murakami, S. & Koide, H. A simulation of the Last Glacial Maximum with a coupled atmosphere-ocean GCM. Geophys. Res. Lett. 28, 2221–2224 (2001).

    Article  Google Scholar 

  11. Hesse, T., Butzin, M., Bickert, T. & Lohmann, G. A model-data comparison of δ13C in the glacial Atlantic Ocean. Paleoceanography 26, PA3220 (2011).

    Article  Google Scholar 

  12. McManus, J., Francois, R., Gherardi, J., Keigwin, L. & Brown-Leger, S. Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate change. Nature 428, 834–837 (2004).

    Article  Google Scholar 

  13. Gherardi, J. et al. Glacial-interglacial circulation changes inferred from 231Pa/230Th sedimentary record in the North Atlantic region. Paleoceanography 24, PA2204 (2009).

    Article  Google Scholar 

  14. Anderson, R. et al. Wind-driven upwelling in the Southern Ocean and the deglacial rise in atmospheric CO2 . Science 323, 1443–1448 (2009).

    Article  Google Scholar 

  15. Bradtmiller, L., Anderson, R., Fleisher, M. & Burckle, L. Opal burial in the equatorial Atlantic Ocean over the last 30 kyr: Implications for glacial-interglacial changes in the ocean silicon cycle. Paleoceanography 22, PA4216 (2007).

    Article  Google Scholar 

  16. Lippold, J. et al. Does sedimentary 231Pa/230Th from the Bermuda Rise monitor past Atlantic Meridional Overturning Circulation? Geophys. Res. Lett. 36, L12601 (2009).

    Article  Google Scholar 

  17. Hall, I. et al. Accelerated drawdown of meridional overturning in the late-glacial Atlantic triggered by transient pre-H event freshwater perturbation. Geophys. Res. Lett. 33, L16616 (2006).

    Article  Google Scholar 

  18. Guihou, A. et al. Late slowdown of the Atlantic Meridional Overturning Circulation during the Last Glacial Inception: New constraints from sedimentary (231Pa/230Th). Earth Planet. Sci. Lett. 289, 520–529 (2010).

    Article  Google Scholar 

  19. Luo, Y., Francois, R. & Allen, S. Sediment 231Pa/230Th as a recorder of the rate of the Atlantic Meridional Overturning Circulation: Insights from a 2-D model. Ocean Sci. 6, 381–400 (2010).

    Article  Google Scholar 

  20. Lippold, J., Gherardi, J. & Luo, Y. Testing the 231Pa/230Th paleocirculation proxy—A data versus 2D model comparison. Geophys. Res. Lett. 38, L20603 (2011).

    Article  Google Scholar 

  21. Francois, R. Proxies in Late Cenozoic Paleoceanography: Paleoflux and Paleocirculation from Sediment 230Th and 231Pa/230Th Ch. 16 (Elsevier, 2007).

    Google Scholar 

  22. Gherardi, J. et al. Reply to comment by S. Peacock on glacial–interglacial circulation changes inferred from 231Pa/230Th sedimentary record in the North Atlantic region. Paleoceanography 25, PA2207 (2010).

    Article  Google Scholar 

  23. Lippold, J., Mulitza, S., Mollenhauer, G., Weyer, S. & Christl, M. Boundary scavenging at the east Atlantic margin does not negate use of Pa/Th to trace Atlantic overturning. Earth Planet. Sci. Lett. 333–334, 317–331 (2012).

    Article  Google Scholar 

  24. Christl, M. et al. 231Pa/230Th: A proxy for upwelling off the coast of West Africa. Nucl. Instrum. Methods Phys. Res. B 268, 1159–1162 (2009).

    Article  Google Scholar 

  25. Scholten, J. et al. Advection and Scavenging: Effect on 230Th and 230Pa distribution off Southwest-Africa. Earth Planet. Sci. Lett. 271, 159–169 (2008).

    Article  Google Scholar 

  26. Anderson, B., Bacon, M. & Brewer, P. Removal of 230Th and 231Pa at ocean margins. Earth Planet. Sci. Lett. 66, 73–90 (1983).

    Article  Google Scholar 

  27. Talley, L., Reid, J. & Robbins, P. Data-based meridional overturning streamfunctions for the global ocean. J. Clim. 16, 3213–3226 (2003).

    Article  Google Scholar 

  28. Kwon, E. et al. North Atlantic ventilation of southern-sourced deep water in the glacial ocean. Paleoceanography 27, PA2208 (2012).

    Article  Google Scholar 

Download references

Acknowledgements

Sediment material for this study was provided by J. Pätzold, the ODP/IODP core repository Bremen, and S. Jaccard. The manuscript benefited from inputs by J-C. Duplessy and C. Waelbroeck. Expertise was provided by M. Andersen, B. Antz, P. Blaser, E. Böhm, M. Christl, E. Christner, M. Deininger, H. Dicht, M. Gutjahr, A. Mangini, S. Rheinberger, M. Ruckelshausen, M. Soon, Q. Supiramaniam, S. Weyer and F. Wombacher. Support for this research was provided by the Deutsche Forschungsgesellschaft, grant Li1815/2 to J.L. and a NSERC Discovery Grant to R.F.

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Authors and Affiliations

  1. Institute of Environmental Physics, University of Heidelberg, 69120 Heidelberg, Germany

    Jörg Lippold

  2. Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada

    Yiming Luo, Roger Francois & Susan E. Allen

  3. LSCE/IPSL Laboratoire CNRS/CEA/UVSQ, domaine du CNRS, 91190 Gif sur Yvette, France

    Jeanne Gherardi

  4. Ecole Normale Supérieure de Lyon, Université Claude Bernard and CNRS, 69364 Lyon, France

    Sylvain Pichat

  5. Department of Earth Sciences, University of Oxford, Oxford, OX1 3AN, UK

    Ben Hickey

  6. Institute for Geosciences, University of Tübingen, 72074 Tübingen, Germany

    Hartmut Schulz

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Contributions

J.L., Y.L., J.G. and R.F. developed the concept and designed the study. J.L., J.G., S.P. and B.H. performed Pa/Th measurements. J.L., Y.L., R.F. and B.H. performed opal measurements. Y.L., R.F. and S.E.A. developed and applied the model. S.P., J.G., B.H. and H.S. provided sample material and age models. J.L., Y.L. and R.F. wrote the manuscript.

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Correspondence to Jörg Lippold.

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The authors declare no competing financial interests.

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Lippold, J., Luo, Y., Francois, R. et al. Strength and geometry of the glacial Atlantic Meridional Overturning Circulation. Nature Geosci 5, 813–816 (2012). https://doi.org/10.1038/ngeo1608

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