Coherent high- and low-latitude control of the northwest African hydrological balance

Article metrics

Abstract

The evolution of the northwest African hydrological balance throughout the Pleistocene epoch influenced the migration of prehistoric humans1. The hydrological balance is also thought to be important to global teleconnection mechanisms during Dansgaard–Oeschger and Heinrich events2. However, most high-resolution African climate records do not span the millennial-scale climate changes of the last glacial–interglacial cycle1,3,4,5, or lack an accurate chronology6. Here, we use grain-size analyses of siliciclastic marine sediments from off the coast of Mauritania to reconstruct changes in northwest African humidity over the past 120,000 years. We compare this reconstruction to simulations of palaeo-humidity from a coupled atmosphere–ocean–vegetation model. These records are in good agreement, and indicate the reoccurrence of precession-forced humid periods during the last interglacial period similar to the Holocene African Humid Period. We suggest that millennial-scale arid events are associated with a reduction of the North Atlantic meridional overturning circulation and that millennial-scale humid events are linked to a regional increase of winter rainfall over the coastal regions of northwest Africa.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Average precipitation rates, surface wind direction and strength over the northeastern Atlantic for boreal winter and summer.
Figure 2: Palaeoenvironmental records of the NGRIP ice core, MD95 2042 and GeoB7920 for the last 120 kyr BP.
Figure 3: Model–data comparison of the northern Africa humidity and vegetation cover during the last 120 kyr BP.
Figure 4: Model–data comparison of the northern Africa humidity and vegetation cover from 65 to 15 kyr BP.

Change history

  • 18 September 2008

    The name of the first affiliation has changed, and has been corrected for all versions of this Letter.

References

  1. 1

    Kuper, R. & Kröpelin, S. Climate-controlled Holocene occupation in the Sahara: Motor of Africa’s evolution. Science 313, 803–807 (2006).

  2. 2

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

  3. 3

    Gasse, F. Hydrological changes in the African tropics since the Last Glacial Maximum. Quat. Sci. Rev. 19, 189–211 (2000).

  4. 4

    Street-Perrott, F. A. & Perrott, R. A. Abrupt climate fluctuations in the tropics: the influence of Atlantic Ocean circulation. Nature 343, 607–612 (1990).

  5. 5

    deMenocal, P. B. et al. Abrupt onset and termination of the African Humid period: Rapid climate response to gradual insolation forcing. Quat. Sci. Rev. 19, 347–361 (2000).

  6. 6

    Zhao, M., Mercer, J. L., Eglinton, G., Higginson, M. J. & Huang, C.-Y. Comparative molecular biomarker assessment of phytoplankton paleoproductivity for the last 160 kyr off Cap Blanc, NW Africa. Org. Geochem. 37, 72–97 (2006).

  7. 7

    Schefuß, E., Schouten, S., Jansen, J. H. F. & Sinninghe Damsté, J. S. African vegetation controlled by tropical sea surface temperatures in the mid-Pleistocene period. Nature 422, 418–421 (2003).

  8. 8

    Weldeab, S., Lea, D. W., Schneider, R. R. & Andersen, N. 155,000 Years of West African Monsoon and Ocean thermal evolution. Science 316, 1303–1307 (2007).

  9. 9

    Claussen, M. et al. Simulation of an abrupt change in Saharan vegetation in the mid-Holocene. Geophys. Res. Lett. 26, 2037–2040 (1999).

  10. 10

    Jolly, D., Harrison, S. P., Damnati, B. & Bonnefille, R. Simulated climate and biomes of Africa during the late quaternary: Comparison with pollen and lake status data. Quat. Sci. Rev. 17, 629–657 (1998).

  11. 11

    Renssen, H., Brovkin, V., Fichefet, T. & Goosse, H. Simulation of the Holocene climate evolution in Northern Africa: The termination of the African Humid Period. Quat. Int. 150, 95–102 (2006).

  12. 12

    Liu, Z. et al. Simulating the transient evolution and abrupt change of Northern Africa atmosphere-ocean-terrestrial ecosystem in the Holocene. Quat. Sci. Rev. 26, 1818–1837 (2007).

  13. 13

    Liu, Z., Wang, Y., Gallimore, R., Notaro, M. & Prentice, I. C. On the cause of abrupt vegetation collapse in North Africa during the Holocene: Climate variability vs. vegetation feedback. Geophys. Res. Lett. 33, L22709 (2006).

  14. 14

    Adegbie, A. T., Schneider, R. R., Rohl, U. & Wefer, G. Glacial millennial-scale fluctuations in central African precipitation recorded in terrigenous sediment supply and freshwater signals offshore Cameroon. Palaeogeogr. Palaeoclimatol. Palaeoecol. 197, 323–333 (2003).

  15. 15

    deMenocal, P. B., Ortiz, J., Guilderson, T. & Sarnthein, M. Coherent high- and low-latitude climate variability during the Holocene Warm Period. Science 288, 2198–2202 (2000).

  16. 16

    Sarnthein, M., Tetzlaff, G., Koopmann, B., Wolter, K. & Pflaumann, U. Glacial and interglacial wind regimes over the eastern subtropical Atlantic and North-West Africa. Nature 293, 193–196 (1981).

  17. 17

    Parkin, D. W. & Shackleton, N. J. Trade wind and temperature correlations down a deep-sea core off the Saharan coast. Nature 245, 455–457 (1973).

  18. 18

    Weltje, G. J. & Prins, M. A. Muddled or mixed? Inferring palaeoclimate from size distributions of deep-sea clastics. Sedim. Geol. 162, 39–62 (2003).

  19. 19

    Holz, C., Stuut, J. b. W. & Henrich, R. Terrigenous sedimentation processes along the continental margin off NW Africa: Implications from grain-size analysis of seabed sediments. Sedimentology 51, 1145–1154 (2005).

  20. 20

    Weltje, G. J. & Prins, M. A. Genetically meaningful decomposition of grain-size distributions. Sedim. Geol. 202, 409–424 (2007).

  21. 21

    Vidal, L. et al. Evidence for changes in the North Atlantic Deep Water linked to meltwater surges during the Heinrich events. Earth Planet. Sci. Lett. 146, 13–27 (1997).

  22. 22

    Chapman, M. R., N J, S. & Duplessy, J.-C. Sea surface temperature variability during the last glacial-interglacial cycle: Assessing the magnitude and pattern of climate change in the North Atlantic. Palaeogeogr. Palaeoclimatol. Palaeoecol. 157, 1–25 (2000).

  23. 23

    Bard, E. Abrupt climate changes over millennial timescales: Climate shock. Phys. Today 55, 32–38 (2002).

  24. 24

    Claussen, M., Fohlmeister, J., Ganopolski, A. & Brovkin, V. Vegetation dynamics amplifies precessional forcing. Geophys. Res. Lett. 33, L09709 (2006).

  25. 25

    Arz, H. W., Lamy, F., Pätzold, J., Müller, P. J. & Prins, M. Mediterranean moisture source for an early-Holocene humid period in the Northern Red Sea. Science 300, 118–121 (2003).

  26. 26

    Claussen, M., Ganopolski, A., Brovkin, V., Gerstengarbe, F. W. & Werner, P. Simulated global-scale response of the climate system to Dansgaard/Oeschger and Heinrich events. Clim. Dyn. 21, 361–370 (2003).

  27. 27

    Allen, J. R. M. et al. Rapid environmental changes in southern Europe during the last glacial period. Nature 400, 740–743 (1999).

  28. 28

    Combourieu Nebout, N. et al. Enhanced aridity and atmospheric high-pressure stability over the western Mediterranean during the North Atlantic cold events of the past 50 kyr. Geology 30, 863–866 (2002).

  29. 29

    Moreno, A. et al. Links between marine and atmospheric processes oscillating on a millennial time-scale. A multi-proxy study of the last 50,000 yr from the Alboran Sea (Western Mediterranean Sea). Quat. Sci. Rev. 24, 1623–1636 (2005).

  30. 30

    NGRIP-Members.High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature 431, 147–151 (2004).

Download references

Acknowledgements

We thank the crew and participants of Meteor cruise M53/1. The authors acknowledge G. J. Weltje for providing the End-Member Model Algorithm and the constructive discussion with A. Ganopolski, E. Bauer, V. Brovkin, H. Arz and M. Prins. M. Segl is thanked for supervising the stable isotope analyses. This research was supported by the Deutsche Forschungsgemeinschaft as part of the DFG Research Center for Ocean Margins of the University of Bremen.

Author information

Experimental work, data analysis and interpretation of the proxy data were carried out by R.T., J.B.W.S., T.B., F.L. and U.R. The CLIMBER model simulations were set up and carried out by M.C., J.F. and A.J.

Correspondence to Rik Tjallingii or Martin Claussen.

Supplementary information

Supplementary Information

Supplementary figures S1-S7 (PDF 608 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Tjallingii, R., Claussen, M., Stuut, J. et al. Coherent high- and low-latitude control of the northwest African hydrological balance. Nature Geosci 1, 670–675 (2008) doi:10.1038/ngeo289

Download citation

Further reading