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UP: Umweltphysik
UP 21: Atmosph
äre und Klima
UP 21.1: Invited Talk
Wednesday, March 15, 2006, 11:30–12:00, A
Possible solar origin of the 1,470-year glacial climate cycle demonstrated in a coupled model — •H. Braun1, M. Christl1, S. Rahmstorf2, A. Ganopolski2, A. Mangini1, C. Kubatzki3, K. Roth4, and B. Kromer1 — 1Heidelberger Akademie der Wissenschaften, c/o Institut für Umweltphysik, Im Neuenheimer Feld 229, 69120 Heidelberg — 2Potsdam-Institut für Klimafolgenforschung, Telegrafenberg A 31, 14473 Potsdam — 3Alfred-Wegener Institut für Polar- und Meeresforschung, Bussestraße 24, 27570 Bremerhaven — 4Institut für Umweltphysik, Im Neuenheimer Feld 229, 69120 Heidelberg
Many palaeoclimate records from the North Atlantic region show rapid climate oscillations, the so-called Dansgaard-Oeschger events, with an apparent quasi-periodicity of 1470 years for the late glacial period. Various hypotheses were suggested to explain these rapid temperature shifts, including internal oscillations in the climate system and external forcing, possibly from the Sun. But whereas pronounced solar cycles of about 87 and 210 years are well known, a 1470-year solar cycle has not been detected. Here we show that an intermediate-complexity climate model with glacial climate conditions simulates rapid climate shifts similar to the Dansgaard-Oeschger events with a spacing of 1470 years when forced by periodic freshwater input into the North Atlantic Ocean in cycles of about 87 and 210 years.
[1] Braun H, Christl M, Rahmstorf S, Ganopolski A, Mangini A, Kubatzki C, Roth K, Kromer B. Possible solar origin of the 1,470-year glacial climate cycle demonstrated in a coupled model. Nature 438, 208 (2005).