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Moisture transport across Central America as a positive feedback on abrupt climatic changes


Moisture transport from the Atlantic to the Pacific ocean across Central America leads to relatively high salinities in the North Atlantic Ocean1 and contributes to the formation of North Atlantic Deep Water2. This deep water formation varied strongly between Dansgaard/Oeschger interstadials and Heinrich events—millennial-scale abrupt warm and cold events, respectively, during the last glacial period3. Increases in the moisture transport across Central America have been proposed to coincide with northerly shifts of the Intertropical Convergence Zone and with Dansgaard/Oeschger interstadials, with opposite changes for Heinrich events4. Here we reconstruct sea surface salinities in the eastern equatorial Pacific Ocean over the past 90,000 years by comparing palaeotemperature estimates from alkenones and Mg/Ca ratios with foraminiferal oxygen isotope ratios that vary with both temperature and salinity. We detect millennial-scale fluctuations of sea surface salinities in the eastern equatorial Pacific Ocean of up to two to four practical salinity units. High salinities are associated with the southward migration of the tropical Atlantic Intertropical Convergence Zone, coinciding with Heinrich events and with Greenland stadials5. The amplitudes of these salinity variations are significantly larger on the Pacific side of the Panama isthmus, as inferred from a comparison of our data with a palaeoclimate record from the Caribbean basin6. We conclude that millennial-scale fluctuations of moisture transport constitute an important feedback mechanism for abrupt climate changes, modulating the North Atlantic freshwater budget and hence North Atlantic Deep Water formation.

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Figure 1: Averaged precipitation rates over South America for March and September for the period ad 1987–2003.
Figure 2: Records of MD02-2529 versus age for the last 90 kyr  bp.
Figure 3: Temporal variations of the calculated Δδ 18 O sw of MD02-2529 compared to other palaeoclimatic records.


  1. Zaucker, F. & Broecker, W. S. The influence of atmospheric moisture transport on the fresh water balance of the Atlantic drainage basin: General circulation model simulations and observations. J. Geophys. Res. 97, 2765–2773 (1992)

    Article  ADS  Google Scholar 

  2. Broecker, W. S., Bond, G., Klas, M., Bonani, G. & Wolfli, W. A salt oscillator in the glacial Atlantic? 1. The concept. Paleoceanography 5, 469–477 (1990)

    Article  ADS  Google Scholar 

  3. Bard, E. Climate shock: Abrupt changes over millennial time scales. Phys. Today 55, 32–37 (2002)

    Article  ADS  Google Scholar 

  4. Peterson, L. C., Haug, G. H., Hughen, K. A. & Röhl, U. Rapid changes in the hydrologic cycle of the tropical Atlantic during the Last Glacial. Science 290, 1947–1951 (2000)

    Article  ADS  CAS  Google Scholar 

  5. Stuiver, M. & Grootes, P. M. GISP2 oxygen isotope ratios. Quat. Res. 53, 277–284 (2000)

    Article  CAS  Google Scholar 

  6. Schmidt, M. W., Spero, H. J. & Lea, D. W. Links between salinity variation in the Caribbean and North Atlantic thermohaline circulation. Nature 428, 160–163 (2004)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  Google Scholar 

  8. Wang, Y. J. et al. A high-resolution absolute-dated late Pleistocene monsoon record from Hulu Cave, China. Science 294, 2345–2348 (2001)

    Article  ADS  CAS  Google Scholar 

  9. Ivanochko, T. S. et al. Variations in tropical convection as an amplifier of global climate change at the millennial scale. Earth Planet. Sci. Lett. 235, 302–314 (2005)

    Article  ADS  CAS  Google Scholar 

  10. Broecker, W. S. Does the trigger for abrupt climate change reside in the ocean or in the atmosphere? Science 300, 1519–1522 (2003)

    Article  ADS  CAS  Google Scholar 

  11. Vidal, L. & Arz, H. in Past Climate Variability Through Europe And Africa (eds Battarbee, R. W. et al.) 31–44 (Springer, Dordrecht, 2004)

    Book  Google Scholar 

  12. Liu, W. T. & Tang, W. Estimating moisture transport over oceans using space-based observations. J. Geophys. Res. 110 D10101 doi: 10.1029/2004JD005300 (2005)

    Article  ADS  Google Scholar 

  13. Manabe, S. & Stouffer, R. J. Two stable equilibria of a coupled ocean-atmosphere model. J. Clim. 1, 841–866 (1988)

    Article  ADS  Google Scholar 

  14. Hostetler, S. W. & Mix, A. C. Reassessment of ice-age cooling of the tropical ocean and atmosphere. Nature 399, 673–676 (1999)

    Article  ADS  CAS  Google Scholar 

  15. Schmittner, A., Meissner, K. J., Eby, M. & Weaver, A. J. Forcing of the deep ocean circulation in simulations of the Last Glacial Maximum. Paleoceanography 17 1015 doi: 10.1029/2001PA000633 (2002)

    Article  ADS  Google Scholar 

  16. Benway, H. M., Mix, A. C., Haley, B. A. & Klinkhammer, G. P. Eastern Pacific Warm Pool paleosalinity and climate variability: 0–30 kyr. Paleoceanography 21 PA3008 doi: 10.1029/2005PA001208 (2006)

    Article  ADS  Google Scholar 

  17. Waelbroeck, C. et al. Sea-level and deep water temperature changes derived from benthic foraminifera isotopic records. Quat. Sci. Rev. 21, 295–305 (2002)

    Article  ADS  Google Scholar 

  18. Benway, H. M. & Mix, A. C. Oxygen isotopes, upper-ocean salinity, and precipitation sources in the eastern tropical Pacific. Earth Planet. Sci. Lett. 224, 493–507 (2004)

    Article  ADS  CAS  Google Scholar 

  19. Wang, X. et al. Wet periods in northeastern Brazil over the past 210 kyr linked to distant climate anomalies. Nature 432, 740–743 (2004)

    Article  ADS  CAS  Google Scholar 

  20. Arz, H. W., Pätzold, J. & Wefer, G. Correlated millennial-scale changes in surface hydrography and terrigenous sediment yield inferred from last-glacial marine deposits off northeastern Brazil. Quat. Res. 50, 157–166 (1998)

    Article  CAS  Google Scholar 

  21. Masson-Delmotte, V. et al. GRIP deuterium excess reveals rapid and orbital-scale changes in Greenland moisture origin. Science 309, 118–121 (2005)

    Article  ADS  CAS  Google Scholar 

  22. Ganopolski, A. & Rahmstorf, S. Rapid changes of glacial climate simulated in a coupled climate model. Nature 409, 153–158 (2001)

    Article  ADS  CAS  Google Scholar 

  23. Masson, S. & Delecluse, P. Influence of the Amazon river runoff on the tropical Atlantic. Phys. Chem. Earth B 26, 137–142 (2001)

    Article  Google Scholar 

  24. Mignot, J. & Frankignoul, C. Interannual to interdecadal variability of sea surface salinity in the Atlantic and its link to the atmosphere in a coupled model. J. Geophys. Res. 109 C04005 doi: 10.1029/2003JC002005 (2004)

    Article  ADS  Google Scholar 

  25. Schmidt, M. W., Vautravers, M. J. & Spero, H. J. Rapid subtropical North Atlantic salinity oscillations across Dansgaard-Oeschger cycles. Nature 443, 561–564 (2006)

    Article  ADS  CAS  Google Scholar 

  26. Sonzogni, C. et al. Temperature and salinity effects on alkenone ratios measured in surface sediments from the Indian Ocean. Quat. Res. 47, 344–355 (1997)

    Article  CAS  Google Scholar 

  27. Lea, D. W., Pak, D. K. & Spero, H. J. Climate impact of Late Quaternary equatorial Pacific sea surface temperature variations. Science 289, 1719–1724 (2000)

    Article  ADS  CAS  Google Scholar 

  28. Schmidt, G. A. Error analysis of paleosalinity calculations. Paleoceanography 14, 422–429 (1999)

    Article  ADS  Google Scholar 

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We acknowledge support from INSU and the French Polar Institute IPEV, which provided the RV Marion Dufresne and the CALYPSO coring system used during the IMAGES VIII MONA cruise. Thanks to Y. Garcin and M. Siddall for discussion and reviews. Paleoclimate work at CEREGE is supported by grants from the CNRS, the ANR and the Gary Comer Science and Education Foundation.

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Correspondence to Guillaume Leduc or Edouard Bard.

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Supplementary Information

This file contains Supplementary Discussion about present-day climatotlogy and hydrology, Supplementary Methods concerning Analytical procedures and Age control, Supplementary Figures 1-5 with legendsand Supplementary Tables 1-2 containing results of core MD02-2529 and radiocarbon data used to construct the age model. This file also contains additional references. (PDF 15246 kb)

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Leduc, G., Vidal, L., Tachikawa, K. et al. Moisture transport across Central America as a positive feedback on abrupt climatic changes. Nature 445, 908–911 (2007).

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