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Uplift of Africa as a potential cause for Neogene intensification of the Benguela upwelling system

Nature Geoscience volume 7, pages 741–747 (2014)Cite this article

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Abstract

The Benguela Current, located off the west coast of southern Africa, is tied to a highly productive upwelling system1. Over the past 12 million years, the current has cooled, and upwelling has intensified2,3,4. These changes have been variously linked to atmospheric and oceanic changes associated with the glaciation of Antarctica and global cooling5, the closure of the Central American Seaway1,6 or the further restriction of the Indonesian Seaway3. The upwelling intensification also occurred during a period of substantial uplift of the African continent7,8. Here we use a coupled ocean–atmosphere general circulation model to test the effect of African uplift on Benguela upwelling. In our simulations, uplift in the East African Rift system and in southern and southwestern Africa induces an intensification of coastal low-level winds, which leads to increased oceanic upwelling of cool subsurface waters. We compare the effect of African uplift with the simulated impact of the Central American Seaway closure9, Indonesian Throughflow restriction10 and Antarctic glaciation11, and find that African uplift has at least an equally strong influence as each of the three other factors. We therefore conclude that African uplift was an important factor in driving the cooling and strengthening of the Benguela Current and coastal upwelling during the late Miocene and Pliocene epochs.

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Figure 1: Vertical cross-sections at 25° S of annual mean horizontal wind speed (representing the low-level Benguela jet) and air temperature.
Figure 2: Annual mean wind vectors at 1,000 hPa (m s−1) and Ekman pumping velocity.
Figure 3: Vertical cross-sections of annual mean ocean temperature and vertical velocity at 25° S, the latitude of the largest Ekman pumping anomaly.
Figure 4: Global change in annual mean sea surface temperature (SST) due to uplift of Africa.
Figure 5: Annual mean surface ocean temperature, flow and vertical heat flux responses to uplift of Africa; differences represent the effect of uplift (HIGH–LOW).

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References

  1. Hay, W. W. & Brock, J. C. Temporal variation in intensity of upwelling off southwest Africa. Geol. Soc. London Spec. Publ. 64, 463–497 (1992).

    Article  Google Scholar 

  2. Rommerskirchen, F., Condon, T., Mollenhauer, G., Dupont, L. & Schefuss, E. Miocene to Pliocene development of surface and subsurface temperatures in the Benguela Current system. Paleoceanography 26, PA3216 (2011).

    Article  Google Scholar 

  3. Rosell-Mele, A., Martinez-Garcia, A. & McClymont, E. L. Persistent warmth across the Benguela upwelling system during the Pliocene epoch. Earth Planet. Sci. Lett. 386, 10–20 (2014).

    Article  Google Scholar 

  4. Marlow, J. R., Lange, C. B., Wefer, G. & Rosell-Mele, A. Upwelling intensification as part of the Pliocene-Pleistocene climate transition. Science 290, 2288–2291 (2000).

    Google Scholar 

  5. Diekmann, B., Falker, M. & Kuhn, G. Environmental history of the south-eastern South Atlantic since the Middle Miocene: Evidence from the sedimentological records of ODP Sites 1088 and 1092. Sedimentology 50, 511–529 (2003).

    Article  Google Scholar 

  6. Prange, M. & Schulz, M. A coastal upwelling seesaw in the Atlantic Ocean as a result of the closure of the Central American Seaway. Geophys. Res. Lett. 31, L17207 (2004).

    Article  Google Scholar 

  7. Roberts, G. G. & White, N. Estimating uplift rate histories from river profiles using African examples. J. Geophys. Res. 115, B02406 (2010).

    Google Scholar 

  8. Chorowicz, J. The East African rift system. J. Afr. Earth Sci. 43, 379–410 (2005).

    Article  Google Scholar 

  9. Zhang, X. et al. Changes in equatorial Pacific thermocline depth in response to Panamanian seaway closure: Insights from a multi-model study. Earth Planet. Sci. Lett. 317, 76–84 (2012).

    Article  Google Scholar 

  10. Krebs, U., Park, W. & Schneider, B. Pliocene aridification of Australia caused by tectonically induced weakening of the Indonesian throughflow. Palaeogeogr. Palaeoclimatol. Palaeoecol. 309, 111–117 (2011).

    Article  Google Scholar 

  11. Goldner, A., Huber, M. & Caballero, R. Does Antarctic glaciation cool the world? Clim. Past 9, 173–189 (2013).

    Article  Google Scholar 

  12. Nicholson, S. E. A low-level jet along the Benguela coast, an integral part of the Benguela Current ecosystem. Climatic Change 99, 613–624 (2010).

    Article  Google Scholar 

  13. Burk, S. D. & Thompson, W. T. The summertime low-level jet and marine boundary layer structure along the California coast. Mon. Weath. Rev. 124, 668–686 (1996).

    Article  Google Scholar 

  14. Nyblade, A. A. & Robinson, S. W. The African Superswell. Geophys. Res. Lett. 21, 765–768 (1994).

    Article  Google Scholar 

  15. Seranne, M. & Anka, Z. South Atlantic continental margins of Africa: A comparison of the tectonic vs climate interplay on the evolution of equatorial west Africa and SW Africa margins. J. Afr. Earth Sci. 43, 283–300 (2005).

    Article  Google Scholar 

  16. Moucha, R. & Forte, A. M. Changes in African topography driven by mantle convection. Nature Geosci. 4, 707–712 (2011).

    Article  Google Scholar 

  17. Pik, R. East Africa on the rise. Nature Geosci. 4, 660–661 (2011).

    Article  Google Scholar 

  18. Erlanger, E. D., Granger, D. E. & Gibbon, R. J. Rock uplift rates in South Africa from isochron burial dating of fluvial and marine terraces. Geology 40, 1019–1022 (2012).

    Article  Google Scholar 

  19. Roberts, E. M. et al. Initiation of the western branch of the East African Rift coeval with the eastern branch. Nature Geosci. 5, 289–294 (2012).

    Article  Google Scholar 

  20. Sepulchre, P. et al. Tectonic uplift and Eastern Africa aridification. Science 313, 1419–1423 (2006).

    Article  Google Scholar 

  21. Al-Hajri, Y., White, N. & Fishwick, S. Scales of transient convective support beneath Africa. Geology 37, 883–886 (2009).

    Article  Google Scholar 

  22. Cohen, A. S., Soreghan, M. J. & Scholz, C. A. Estimating the age of formation of lakes — an example from Lake Tanganyika, East-African Rift system. Geology 21, 511–514 (1993).

    Article  Google Scholar 

  23. Sepulchre, P., Sloan, L. C., Snyder, M. & Fiechter, J. Impacts of Andean uplift on the Humboldt Current system: A climate model sensitivity study. Paleoceanography 24, PA4215 (2009).

    Article  Google Scholar 

  24. Collins, W. D. et al. The community climate system model version 3 (CCSM3). J. Clim. 19, 2122–2143 (2006).

    Article  Google Scholar 

  25. Holt, T. R. Mesoscale forcing of a boundary layer jet along the California coast. J. Geophys. Res. 101, 4235–4254 (1996).

    Article  Google Scholar 

  26. Large, W. G. & Danabasoglu, G. Attribution and impacts of upper-ocean biases in CCSM3. J. Clim. 19, 2325–2346 (2006).

    Article  Google Scholar 

  27. Dekens, P. S., Ravelo, A. C. & McCarthy, M. D. Warm upwelling regions in the Pliocene warm period. Paleoceanography 22, PA3211 (2007).

    Article  Google Scholar 

  28. Oleson, K. W. et al. Improvements to the Community Land Model and their impact on the hydrological cycle. J. Geophys. Res. 113, G01021 (2008).

    Article  Google Scholar 

  29. Grodsky, S. A., Carton, J. A., Nigam, S. & Okumura, Y. M. Tropical Atlantic biases in CCSM4. J. Clim. 25, 3684–3701 (2012).

    Article  Google Scholar 

  30. Veitch, J., Penven, P. & Shillington, F. Modeling equilibrium dynamics of the Benguela Current system. J. Phys. Oceanogr. 40, 1942–1964 (2010).

    Article  Google Scholar 

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Acknowledgements

This work was funded by the Deutsche Forschungsgemeinschaft (DFG) Research Center/Excellence Cluster ‘The Ocean in the Earth System’. The authors would like to thank G. Strand (NCAR) for making available the spun-up pre-industrial control run restart files. Thanks also to B. Briegleb (NCAR) for making pre-industrial aerosol data available. Special thanks to X. Zhang (MARUM), A. Goldner (Purdue University), U. Krebs-Kanzow (AWI) and S. Khon (University of Kiel) for kindly making available data of additional model simulations of Panama closure, Antarctic glaciation and Indonesian Throughflow restriction. The CCSM3 experiments were run on the SGI Altix Supercomputer of the ‘Norddeutscher Verbund für Hoch- und Höchstleistungsrechnen’ (HLRN).

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  1. MARUM - Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, 28334 Bremen, Germany

    Gerlinde Jung, Matthias Prange & Michael Schulz

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  1. Gerlinde Jung
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Contributions

M.P. and M.S. developed the project. G.J., M.P. and M.S. interpreted the model results and wrote the paper. G.J. performed the model simulations, analysed the model results and created the figures.

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Correspondence to Gerlinde Jung.

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The authors declare no competing financial interests.

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Jung, G., Prange, M. & Schulz, M. Uplift of Africa as a potential cause for Neogene intensification of the Benguela upwelling system. Nature Geosci 7, 741–747 (2014). https://doi.org/10.1038/ngeo2249

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