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

• Published in: Science (American Association for the Advancement of Science) Vol. 322; no. 5899; pp. 252 - 255
• Main Authors: Tierney, Jessica E, Russell, James M, Huang, Yongsong, Damsté, Jaap S. Sinninghe, Hopmans, Ellen C, Cohen, Andrew S
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 10.10.2008; The American Association for the Advancement of Science
• Subjects: Carbon; Climate change; Climate models; Earth sciences; Earth, ocean, space; Exact sciences and technology; Geochemistry; Lakes; Marine and continental quaternary; Northern hemisphere; Paleoclimatology; Paleoecology; Precipitation; Rain; Sediments; Surficial geology; Tropical climates; Tropical regions; Waxes; East African Lakes; Indian Ocean; Southern Africa; Lake Tanganyika; Africa; Africa, Tanganyika L; ISW, Indian Ocean; AS, Atlantic, Intertropical Convergence Zone; carbon dioxide; stable isotopes; controls; hydrology; atmospheric precipitation; Quaternary; paleotemperature; tropical zone; concentration; upper Quaternary; paleoclimate; insolation; lake sediments; glaciation; Northern Hemisphere; surface temperature; migration; Cenozoic; Phanerozoic; D/H; monsoons; climate change
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1160485

The processes that control climate in the tropics are poorly understood. We applied compound-specific hydrogen isotopes (δD) and the TEX₈₆ (tetraether index of 86 carbon atoms) 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 increase ~3000 years before atmospheric carbon dioxide concentrations. δD 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 by migration of the Intertropical Convergence Zone.