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Rapid changes in the mechanism of ocean convection during the last glacial period

Nature volume 401, pages 458–461 (1999)Cite this article

Abstract

High-amplitude, rapid climate fluctuations are common features of glacial times. The prominent changes in air temperature recorded in the Greenland ice cores1,2 are coherent with shifts in the magnitude of the northward heat flux carried by the North Atlantic surface ocean3,4; changes in the ocean's thermohaline circulation are a key component in many explanations of this climate flickering5. Here we use stable-isotope and other sedimentological data to reveal specific oceanic reorganizations during these rapid climate-change events. Deep water was generated more or less continuously in the Nordic Seas during the latter part of the last glacial period (60 to 10 thousand years ago), but by two different mechanisms. The deep-water formation occurred by convection in the open ocean during warmer periods (interstadials). But during colder phases (stadials), a freshening of the surface ocean reduced or stopped open-ocean convection, and deep-water formation was instead driven by brine-release during sea-ice freezing. These shifting magnitudes and modes nested within the overall continuity of deep-water formation were probably important for the structuring and rapidity of the prevailing climate changes.

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Figure 1: Stratigraphic data sets.
Figure 2: Climate proxy data in sediment cores MD95-2010 and ENAM93-21 (ref.
Figure 3: Relationships between salinity, δ18O and sea-ice formation.

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References

  1. Dansgaard,W. et al. Evidence for general instability of past climate from a 250-kyr ice core record. Nature 364, 218–220 (1993).

    Article  ADS  Google Scholar 

  2. Grootes,P. M., Stuvier,M., White,J. W. C., Johnsen,S. & Jouzel,J. Comparison of oxygen isotope records from the GISP2 and GRIP Greenland Ice cores. Nature 366, 552–554 (1993).

    Article  ADS  CAS  Google Scholar 

  3. Bond,G. et al. Correlation between climate records from North Atlantic sediments and Greenland ice. Nature 365, 143–147 (1993).

    Article  ADS  Google Scholar 

  4. Bond,G. C. & Lotti,R. Iceberg discharges into the North Atlantic on millennial timescales during the last glaciation. Science 267, 1,005–1,010 (1995).

    Article  CAS  Google Scholar 

  5. Broecker,W. S. Thermohaline circulation, the Achilles heel of our climate system: Will man made CO2 upset the current balance? Science 278, 1,582–1,588 (1997).

    Article  CAS  Google Scholar 

  6. Rasmussen,T., Thomsen,E., Labeyrie,L. & van Weering,T. C. E. Circulation changes in the Faeroe–Shetland Channel correlating with cold events during the last glacial period 58–10 ka BP. Geology 24, 937–940 (1996).

    Article  ADS  CAS  Google Scholar 

  7. Shackleton,N. J. Oxygen isotopes, ice volume and sea level. Quat. Sci. Rev. 6, 183–190 (1987).

    Article  ADS  Google Scholar 

  8. Shackleton,N. J. Attainment of isotopic equilibrium between ocean water and the benthonic foraminifera genus Uvigirina: Isotopic changes in the ocean during the last glacial. Colloques Int. CNRS 219, 203–210 (1974).

    Google Scholar 

  9. Manabe,S. & Stouffer,R. J. Simulation of abrupt climatic change induced by freshwater input to the North Atlantic Ocean. Nature 378, 165–167 (1995).

    Article  ADS  CAS  Google Scholar 

  10. Manabe,S. & Stouffer,R. J. Coupled ocean–atmosphere model response to freshwater input: Comparison to younger Dryas event. Paleoceanography 12, 321–336 (1997).

    Article  ADS  Google Scholar 

  11. Craig,H. & Gordon,L. I. in Stable Isotope in Oceanographic Studies and Paleotemperatures (ed. Tongiorgi, T.) 9–130 (Cons. Nazional Rich. Lab. Geol. Nucl., Pisa, Italy, 1965).

    Google Scholar 

  12. Zahn,R. et al. Thermohaline instability in the north Atlantic during meltwater events: Stable isotope and ice rafted detritus records from core SO75-26KL, Portuguese margin. Paleoceanography 12, 696–710 (1997).

    Article  ADS  Google Scholar 

  13. Oppo,D. W. & Lehman,S. J. Suborbital timescale variability of North Atlantic Deep Water during the past 200,000 years. Paleoceanography 10, 901–910 (1995).

    Article  ADS  Google Scholar 

  14. Oppo,D. W. & Lehman,S. J. Mid-depth circulation of the subpolar North Atlantic during the last glacial maximum. Science 259, 1,148–1,152 (1993).

    Article  CAS  Google Scholar 

  15. Lehman,S. J., Wright,D. G. & Stocker,T. F. in Ice in the Climate System (ed. Peltier, W. R.) 187–209 (NATO ASI Series I, Vol. 12, Springer, Berlin, 1993).

    Book  Google Scholar 

  16. Grootes,P. M. & Stuvier,M. Oxygen 18/16 variability in Greenland snow and ice with 10-3–105-year time resolution. J. Geophys. Res. 102, 26,455–26,470 (1997).

    Article  ADS  CAS  Google Scholar 

  17. Mayewski,P. A. et al. Major feature and forcing of high-latitude northern hemisphere atmospheric circulation using a 110,000-year-long glaciochemical series. J. Geophys. Res. 102, 26,345–26,366 (1997).

    Article  ADS  CAS  Google Scholar 

  18. Broecker,W. S. The great ocean conveyor. Oceanography 4, 79–89 (1991).

    Article  Google Scholar 

  19. Berger,W. H. & Jansen,E. in The Younger Dryas (eds. Troelstra, S. R. et al.) 61–105 (Royal Dutch Academy of Scientific Processes, Amsterdam, Netherlands, 1995).

    Google Scholar 

  20. Cortijo,E. et al. Changes in sea surface hydrology associated with Heinrich event 4 in the North Atlantic Ocean between 40° and 60° N. Earth Planet. Sci. Lett. 146, 29–45 (1997).

    Article  ADS  CAS  Google Scholar 

  21. Korsun,S. A. & Polyak,L. V. Distribution of benthic foraminiferal morphogroups in the Barents Sea. Oceanology 29, 838–844 (1989).

    Google Scholar 

  22. Jansen,E., Bleil,U., Henrich,R., Kringstad,L. & Slettemark,B. Paleoenvironmental changes in the Norwegian Sea and the Northwest Atlantic during the last 2.8 m.y.: Deep Sea Drilling Project/Ocean Drilling Program sites 610, 642, 643 and 644. Paleoceanography 3, 563–581 (1988).

    Article  ADS  Google Scholar 

  23. Graham,D. W., Corliss,B. H., Bender,M. L. & Keigwin,L. D. Carbon and oxygen disequilibria of recent deep-sea bethic foraminifera. Mar. Micropaleontol. 6, 483–497 (1981).

    Article  ADS  Google Scholar 

  24. Bard,E., Arnold,M. & Hamelin,B. Present status of the radiocarbon calibration for the last Pleistocene. GEOMAR-Rep. 15, 52–53 (1992).

    Google Scholar 

  25. Martinson,D. G. et al. Age dating and the orbital theory of the ice ages: Development of a high resolution 0 to 300,000-year chronostratigraphy. Quat. Res. 27, 1–29 (1987).

    Article  CAS  Google Scholar 

  26. Meese,D. A. et al. Preliminary depth-age scale of the GISP2 ice core. CRREL Spec. Rep. 94-1 (US Army Cold Region Research and Engineering Laboratory, Hanover, NH, 1987).

  27. Bender,M. et al. Climate correlations between Greenland and Antarctica during the past 100,000 years. Nature 372, 663–666 (1994).

    Article  ADS  CAS  Google Scholar 

  28. Labeyrie,L. D., Duplessy,J. C. & Blanc,P. L. Variation in mode of formation and temperature of oceanic deep waters over the past 125,000 years. Nature 327, 477–482 (1987).

    Article  ADS  CAS  Google Scholar 

  29. Weinelt,M. et al. Ice free Nordic Seas during the last glacial maximum? Potential sites of deepwater formation. Paleoclimates 1, 283–309 (1996).

    Google Scholar 

  30. Fairbanks,R. G. A 17,000-year glacio-eustatic sea level record: influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation. Nature 342, 637–642 (1989).

    Article  ADS  Google Scholar 

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Acknowledgements

We thank L. Labeyrie, and the science party and crew of the Marion Dufresne and the IMAGES program, C. Kissel, E. Boyle and T. Rasmussen. We acknowledge the support of the French agencies MENRT, TAAF, CNRS/INSU and IFRTP. We also thank S. Østerhus, R. Søraas and O. Hansen. This work was funded by the Norwegian Science Foundation and the Environment and Climate program of the European Union.

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Authors and Affiliations

  1. Department of Geology, University of Bergen, Allegt. 41, Bergen, N-5007, Norway

    Trond M. Dokken & Eystein Jansen

  2. The University Courses on Svalbard (UNIS), PO Box 156, Longyearbyen, N-9170, Norway

    Trond M. Dokken

  3. Nansen Environmental and Remote Sensing Centre, Bergen, Norway

    Eystein Jansen

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  1. Trond M. Dokken
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Correspondence to Trond M. Dokken.

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Dokken, T., Jansen, E. Rapid changes in the mechanism of ocean convection during the last glacial period. Nature 401, 458–461 (1999). https://doi.org/10.1038/46753

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