International Journal of Earth Sciences

, Volume 99, Issue 7, pp 1677–1686 | Cite as

Impacts of tectonic and orbital forcing on East African climate: a comparison based on global climate model simulations

  • Frank KasparEmail author
  • Kerstin Prömmel
  • Ulrich Cubasch
Original Paper


A global atmosphere–ocean model has been forced with topographic and orbital scenarios in order to evaluate the relative role of both factors for the past climate of East Africa. Forcing the model with a significantly reduced topography in Eastern and Southern Africa leads to a distinct increase in moisture transport from the Indian Ocean into the eastern part of the continent and increased precipitation in Eastern Africa. Simulations with step-wise reduced height show that this climate change occurs continuously with the change in topography, i.e., an abrupt change of local climatic features with a critical height is not found. Simulations of the last interglacial (at 125,000 years before present, i.e., the Eemian interglacial) and the last glacial inception (at 115,000 years before present) are used as examples for the role of orbital-induced changes in insolation. Here, changes in meridional temperature gradients lead to modifications in moisture transport of similar order of magnitude, but with different spatial and seasonal structure. For the Eemian interglacial, a distinct increase in summer moisture transport from the Atlantic deep into the continent at around 20°N is simulated.


Climate simulation Paleoclimate Africa East African Rift System Tectonics Orbital forcing Interglacial Glacial Quaternary Cenozoic Human evolution 



We are grateful to Pierre Sepulchre for fruitful discussions and providing his topographic scenarios. The study was performed within the research group RiftLink, which is financially supported by the Deutsche Forschungsgemeinschaft (DFG research unit 703). The ECHO-G model was provided by the Model and Data Group at the Max-Planck-Institute for Meteorology (Hamburg, Germany). The simulations were run on the facilities of the German Climate Computing Centre (DKRZ, Hamburg). We thank Stefanie Legutke, Ingo Kirchner and Stephan J. Lorenz for supporting the preparation of the simulations. We would like to thank the anonymous reviewers for their constructive suggestions and comments.


  1. Anyah RO, Semazzi FHM (2007) Variability of East African rainfall based on multiyear RegCM3 simulations. Int J Climatol 27:358–371. doi: 10.1002/joc.1401 CrossRefGoogle Scholar
  2. Berger AL (1978) Long-term variations of daily insolation and quaternary climate changes. J Atmos Sci 35:2362–2367CrossRefGoogle Scholar
  3. Berger A, Loutre MF (1991) Insolation values for the climate of the last 10 million years. Quat Sci Rev 10:297–317CrossRefGoogle Scholar
  4. Berger A, Loutre MF, Kaspar F, Lorenz SJ (2007) Insolation during interglacials. In: Sirocko F, Litt T, Claussen M, Sánchez-Goñi MF (eds) The climate of past interglacials, Chap. 4. Elsevier, Amsterdam, pp 13–27Google Scholar
  5. Felis T, Lohmann G, Kuhnert H, Lorenz SJ, Scholz D, Pätzold J, Al-Rousan SA, Al-Moghrabi SM (2004) Increased seasonality in Middle East temperatures during the last interglacial period. Nature 429:164–168CrossRefGoogle Scholar
  6. Hay WW (1996) Tectonics and climate. Geol Rundsch 85:409–437CrossRefGoogle Scholar
  7. Indeje M, Semazzi FHM, Ogallo LJ (2000) ENSO signals in East African rainfall seasons. Int J Climatol 20:19–46CrossRefGoogle Scholar
  8. Indeje M, Semazzi FHM, Xie L (2001) Mechanistic model simulations of the East African climate using NCAR regional climate model: influence of the large-scale orography on the Turkana low-level jet. J Climate 14:2710–2724CrossRefGoogle Scholar
  9. Kaspar F, Cubasch U (2007a) Simulations of the Eemian interglacial and the subsequent glacial inception with a coupled ocean–atmosphere general circulation model. In: Sirocko F, Litt T, Claussen M, Sánchez-Goñi MF (eds) The climate of past interglacials, Chap. 33. Elsevier, Amsterdam, pp 499–515Google Scholar
  10. Kaspar F, Cubasch U (2007b) Simulation of the Eemian interglacial and possible mechanisms for the glacial inception. In: Harff J, Hay B, Tetzlaff D (eds) Coastline changes: interrelation of climate and geological processes. Geological Society of America, Special Paper 426, Chap. 3, pp 29–42. doi: 10.1130/2007.2426(03)
  11. Kaspar F, Cubasch U (2008) Simulation of East African precipitation patterns with the regional climate model CLM. Met Z 17(4):511–517. doi: 10.1127/0941-2948/2008/0299 CrossRefGoogle Scholar
  12. Kaspar F, Kühl N, Cubasch U, Litt T (2005) A model-data-comparison of European temperatures in the Eemian interglacial. Geophys Res Lett 32:L11703. doi: 10.1029/2005GL022456 CrossRefGoogle Scholar
  13. Kukla GJ, Bender ML, de Beaulieu JL, Bond G, Broecker WS, Cleveringa P, Gavin JE, Herbert TD, Imbrie J, Jouzel J, Keigwin LD, Knudsen KL, McManus JF, Merkt J, Muhs DR, Müller H, Poore RZ, Porter SC, Seret G, Shackleton NJ, Turner C, Tzedakis PC, Winograd IJ (2002) Last interglacial climates. Quat Res 58:2–13CrossRefGoogle Scholar
  14. Legutke S, Voss R (1999) The Hamburg atmosphere-ocean coupled circulation model ECHO-G. Technical Report 18, Deutsches Klimarechenzentrum, HamburgGoogle Scholar
  15. Levitus S, Burgett R, Boyer TP (1994) World Ocean Atlas. Vol. 3, salinity and vol. 4, temperature. NOAA Atlas NESDIS 3/4, U. S. Government Printing Office, Washington, DCGoogle Scholar
  16. Maslin MA, Christensen B (2007) Tectonics, orbital forcing, global climate change, and human evolution in Africa: introduction to the African paleoclimate special volume. J Hum Evol 53:443–464CrossRefGoogle Scholar
  17. McHugh MJ (2004) Near-surface zonal flow and East African precipitation receipt during austral summer. J Climate 17(20):4070–4079CrossRefGoogle Scholar
  18. Min SK, Legutke S, Hense A, Kwon WT (2005) Internal variability in a 1000-year control simulation with the coupled climate model ECHO-G. Part I: near surface temperature, precipitation, and mean sea-level pressure. Tellus A 57(4):605–621CrossRefGoogle Scholar
  19. Schneider U, Fuchs T, Meyer-Christoffer A, Rudolf B (2008) Global precipitation analysis products of the GPCC. Global Precipitation Climatology Centre (GPCC), Deutscher Wetterdienst, Offenbach am Main, Germany. Available at
  20. Schreck CJ, Semazzi FHM (2004) Variability of the recent climate of Eastern Africa. Int J Climatol 24:681–701. doi: 10.1002/joc.1019 CrossRefGoogle Scholar
  21. Sepulchre P, Ramstein G, Fluteau F, Schuster M, Tiercelin JJ, Brunet M (2006) Tectonic uplift and Eastern Africa aridification. Science 313:1419–1423CrossRefGoogle Scholar
  22. Slingo J, Spencer H, Hoskins B, Berrisford P, Black E (2005) The meteorology of the Western Indian Ocean, and the influence of the East African Highlands. Philos Trans R Soc A 363:25–42. doi: 10.1098/rsta.2004-1473 CrossRefGoogle Scholar
  23. Sun L, Semazzi FHM, Giorgi F, Ogallo L (1999) Application of the NCAR regional climate model to eastern Africa. 1. Simulation of the short rains of 1988. J Geophys Res 104(D6):6529–6548CrossRefGoogle Scholar
  24. Tjallingii R, Claussen M, Stuut JBW, Fohlmeister J, Jahn A, Bickert T, Lamy F, Röhl U (2008) Coherent high- and low-latitude control of the northwest African hydrological balance. Nat Geosci 1:670–675. doi: 10.1038/ngeo289 CrossRefGoogle Scholar
  25. Vettoretti G, Peltier WR (2004) Sensitivity of glacial inception to orbital and greenhouse gas climate forcing. Quat Sci Rev 23:499–519CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Frank Kaspar
    • 1
    • 2
    Email author
  • Kerstin Prömmel
    • 1
  • Ulrich Cubasch
    • 1
  1. 1.Institute for MeteorologyFreie Universität BerlinBerlinGermany
  2. 2.Satellite Application Facility on Climate Monitoring (CM-SAF)OffenbachGermany

Personalised recommendations