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Published Online September 11, 2008
Science DOI: 10.1126/science.1160485

Reports

Submitted on May 14, 2008
Accepted on September 2, 2008

Northern Hemisphere Controls on Tropical Southeast African Climate During the Past 60,000 Years

Jessica E. Tierney 1*, James E. Russell 1, Yongsong Huang 1, Jaap S. Sinninghe Damsté 2, Ellen C. Hopmans 2, Andrew S. Cohen 3

1 Department of Geological Sciences, Brown University, Providence, RI 02912, USA.
2 Department of Marine Organic Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, 1790 AB Den Burg, Netherlands.
3 Department of Geosciences, University of Arizona, Tucson, AZ 85721, USA.

* To whom correspondence should be addressed.
Jessica E. Tierney , E-mail: Jessica_Tierney{at}brown.edu

The processes that control climate in the tropics are poorly understood. Here, we apply compound-specific hydrogen isotopes ({delta}D) and the TEX86 temperature proxy to sediment cores from Lake Tanganyika to independently reconstruct precipitation and temperature variations during the past 60,000 years. Tanganyika temperatures follow northern hemisphere insolation, and indicate that warming in tropical Southeast Africa during the last glacial termination began to rise ~3000 years before atmospheric carbon dioxide concentrations. {delta}D data show that this region experienced abrupt changes in hydrology coeval with orbital and millennial-scale events recorded in northern hemisphere monsoonal climate records. This implies that precipitation in tropical Southeast Africa is more strongly controlled by changes in Indian Ocean sea-surface temperatures and the winter Indian monsoon than migration of the Inter-Tropical Convergence Zone.




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Science. ISSN 0036-8075 (print), 1095-9203 (online)