title: A progressively wetter climate in southern East Africa over the past 1.3 million years.
abstract: African climate is generally considered to have evolved towards progressively drier conditions over the past few million years, with increased variability as glacial-interglacial change intensified worldwide. Palaeoclimate records derived mainly from northern Africa exhibit a 100,000-year (eccentricity) cycle overprinted on a pronounced 20,000-year (precession) beat, driven by orbital forcing of summer insolation, global ice volume and long-lived atmospheric greenhouse gases. Here we present a 1.3-million-year-long climate history from the Lake Malawi basin (10°-14° S in eastern Africa), which displays strong 100,000-year (eccentricity) cycles of temperature and rainfall following the Mid-Pleistocene Transition around 900,000 years ago. Interglacial periods were relatively warm and moist, while ice ages were cool and dry. The Malawi record shows limited evidence for precessional variability, which we attribute to the opposing effects of austral summer insolation and the temporal/spatial pattern of sea surface temperature in the Indian Ocean. The temperature history of the Malawi basin, at least for the past 500,000 years, strongly resembles past changes in atmospheric carbon dioxide and terrigenous dust flux in the tropical Pacific Ocean, but not in global ice volume. Climate in this sector of eastern Africa (unlike northern Africa) evolved from a predominantly arid environment with high-frequency variability to generally wetter conditions with more prolonged wet and dry intervals.
authors: Large Lakes Observatory and Department of Earth and Environmental Sciences, University of Minnesota Duluth, Duluth, Minnesota 55812, USA.|Department of Geosciences, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA.
authors: T C
authors: TC
authors: Johnson
authors: Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
authors: J P
authors: JP
authors: Werne
authors: Large Lakes Observatory and Department of Earth and Environmental Sciences, University of Minnesota Duluth, Duluth, Minnesota 55812, USA.
authors: E T
authors: ET
authors: Brown
authors: Department of Earth and Planetary Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, New South Wales 2109, Australia.
authors: A
authors: A
authors: Abbott
authors: Department of Civil &Environmental Engineering &Earth Sciences, University of Notre Dame, 257 Fitzpatrick Hall, Notre Dame, Indiana 46556, USA.
authors: M
authors: M
authors: Berke
authors: Large Lakes Observatory and Department of Earth and Environmental Sciences, University of Minnesota Duluth, Duluth, Minnesota 55812, USA.
authors: B A
authors: BA
authors: Steinman
authors: Large Lakes Observatory and Department of Earth and Environmental Sciences, University of Minnesota Duluth, Duluth, Minnesota 55812, USA.
authors: J
authors: J
authors: Halbur
authors: Departamento de Química Ambiental and Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile.
authors: S
authors: S
authors: Contreras
authors: Large Lakes Observatory and Department of Earth and Environmental Sciences, University of Minnesota Duluth, Duluth, Minnesota 55812, USA.
authors: S
authors: S
authors: Grosshuesch
authors: Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 94709, USA.
authors: A
authors: A
authors: Deino
authors: Earth Sciences Department, Syracuse University, 011a Heroy Geology Laboratory, Syracuse, New York 13244, USA.
authors: C A
authors: CA
authors: Scholz
authors: Earth Sciences Department, Syracuse University, 011a Heroy Geology Laboratory, Syracuse, New York 13244, USA.
authors: R P
authors: RP
authors: Lyons
authors: NIOZ Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands.|Faculty of Geosciences, Department of Earth Sciences, Utrecht University, PO Box 80.021, 3508 TA Utrecht, The Netherlands.
authors: S
authors: S
authors: Schouten
authors: NIOZ Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands.|Faculty of Geosciences, Department of Earth Sciences, Utrecht University, PO Box 80.021, 3508 TA Utrecht, The Netherlands.
authors: J S Sinninghe
authors: JS
authors: Damsté
mesh_terms: D000351:Africa, Eastern; D000473:Alkanes / Q000032:analysis; D001272:Atmosphere / Q000737:chemistry; D002118:Calcium / Q000032:analysis; D002245:Carbon Dioxide / Q000032:analysis; D002980:Climate; D003889:Desert Climate; D004391:Dust / Q000032:analysis; D049690:History, Ancient; D007053:Ice / Q000032:analysis; D019156:Indian Ocean; D060106:Lakes; D008295:Malawi; D018515:Plant Leaves / Q000737:chemistry; D010944:Plants; D011891:Rain; D012621:Seasons; D013696:Temperature; D014885:Waxes / Q000737:chemistry
chemical_list: D000473:Alkanes; D004391:Dust; D007053:Ice; D014885:Waxes; D002245:Carbon Dioxide; D002118:Calcium