Affiliation: | (1) Natural Resources Division, Paul Smith s College, Paul Smiths, NY 12970, USA;(2) Climate Studies Center, Institute for Quaternary and Climate Studies, University of Maine, 04469 Orono, ME , USA;(3) Department of Geography, Loughborough University, LE11 3TU Loughborough, Leicestershire, United Kingdom;(4) P.E.A.R.L., Biology Department, Queen s University, K7L 3N6 Kingston, ONT, Canada;(5) Climate Change Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, 03824 Durham, NH, USA;(6) Swiss Federal Institute of Environmental Science and Technology (EAWAG), CH-8600 Dübendorf, Switzerland |
Abstract: | A new diatom series with 1–6 year resolution from Lake Victoria, East Africa, shows that lake level minima occurred ca. 820–760, 680–660, 640–620, 370–340, and 220–150 calendar years BP. Inferred lake levels were exceptionally high during most of the Little Ice Age (ca. 600–200 calendar years BP). Synchrony between East African high lake levels and prolonged sunspot minima during much of the last millenium may reflect solar variability s effects on tropical rainfall, but those relationships reversed sign ca. 200 years ago. Historical records also show that Victoria lake levels rose during every peak of the ca. 11-year sunspot cycle since the late 19th century. These findings suggest that, if these apparent tropical sun–climate associations during the last millenium were real, then they were subject to abrupt sign reversals.Electronic Supplementary Material to this article is available at . |