HR: 08:15h
AN: U41B-02 INVITED     [Abstracts]
TI: Solar Forcing of Abrupt Glacial Climate Change in a Coupled Climate System Model
AU: * Braun, H
EM: Holger.Braun@iup.uni-heidelberg.de
AF: Heidelberg Academy of Sciences, c/o Institute for Environmental Physics, University of Heidelberg, Im Neuenheimer Feld 229, Heidelberg, 69120 Germany
AU: Christl, M
EM: Marcus.Christl@iup.uni-heidelberg.de
AF: Heidelberg Academy of Sciences, c/o Institute for Environmental Physics, University of Heidelberg, Im Neuenheimer Feld 229, Heidelberg, 69120 Germany
AU: Rahmstorf, S
EM: Stefan.Rahmstorf@pik-potsdam.de
AF: Potsdam Institute for Climate Impact Research, PO Box 601203, Potsdam, 14412 Germany
AU: Ganopolski, A
EM: Andrey.Ganopolski@pik-potsdam.de
AF: Potsdam Institute for Climate Impact Research, PO Box 601203, Potsdam, 14412 Germany
AU: Mangini, A
EM: Augusto.Mangini@iup.uni-heidelberg.de
AF: Heidelberg Academy of Sciences, c/o Institute for Environmental Physics, University of Heidelberg, Im Neuenheimer Feld 229, Heidelberg, 69120 Germany
AU: Kubatzki, C
EM: Claudia.Kubatzki@pik-potsdam.de
AF: Potsdam Institute for Climate Impact Research, PO Box 601203, Potsdam, 14412 Germany
AU: Roth, K
EM: Kurt.Roth@iup.uni-heidelberg.de
AF: Institute for Environmental Physics, University of Heidelberg, Im Neuenheimer Feld 229, Heidelberg, 69120 Germany
AU: Kromer, B
EM: Bernd.Kromer@iup.uni-heidelberg.de
AF: Heidelberg Academy of Sciences, c/o Institute for Environmental Physics, University of Heidelberg, Im Neuenheimer Feld 229, Heidelberg, 69120 Germany
AB: Various climate archives show a quasi-periodicity of about 1470 years in the North Atlantic region. In the last Glacial, this cycle manifests itself in prominent warmings, the Dansgaard-Oeschger events. In the Holocene, a drift-ice cycle of approximately 1500 years coincides with "rapid (100- to 200-year), conspicuously large amplitude variations" in proxies of solar activity [1], which suggests a solar origin of the 1470-year climate cycle. Using the coupled climate system model CLIMBER-2 we show that the combined effect of two well-known centennial-scale solar cycles could explain the timing of the Dansgaard-Oeschger events. These pronounced cycles, the Gleissberg and DeVries cycles with almost stable periods near 87 and 210 years, are close to prime factors of 1470 years. Due to the dynamics inherent in the simulated Dansgaard-Oeschger events, i.e. the threshold behavior and the thermal inertia of the thermohaline circulation, the combined effect of the two solar cycles results in a very robust 1470-year timescale of these events for Glacial conditions. [1] Bond, G. et al., Persistent Solar Influence on North Atlantic Climate During the Holocene, Science 294, 2130-2136 (2001); published online 15 November 2001 (10.1126/science.1065680)
DE: 7536 Solar activity cycle (2162)
DE: 3344 Paleoclimatology
DE: 4203 Analytical modeling
DE: 4267 Paleoceanography
DE: 3220 Nonlinear dynamics
SC: Union [U]
MN: 2004 AGU Fall Meeting