HR: 1340h
AN: U43A-0746 [Abstracts]
TI: Solar Forcing of Abrupt Glacial Climate Change in a Coupled Climate System Model and in a Simple
Conceptual Model
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: * 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: Rahmstorf, S
EM: Stefan.Rahmstorf@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: 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
AU: Ganopolski, A
EM: Andrey.Ganopolski@pik-potsdam.de
AF: Potsdam Institute for Climate Impact Research, PO Box 601203, Potsdam, 14412
Germany
AU: Kubatzki, C
EM: Claudia.Kubatzki@pik-potsdam.de
AF: Potsdam Institute for Climate Impact Research, PO Box 601203, Potsdam, 14412
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.
The coupled climate system model CLIMBER-2 is able to reproduce many features of the observed Dansgaard-Oeschger events when
forced by two well-known centennial-scale solar cycles, the Gleissberg and DeVries cycles with periods near 87 and 210 years.
Due to the model dynamics, i.e. the threshold behavior and the thermal inertia of the thermohaline circulation, the combined
effect of these two cycles results in a very robust 1470-year timescale of the model response for Glacial conditions.
Here we show how a very simple conceptual model, which incorporates only the threshold character and the thermal inertia of
the THC, can be used to clarify the dynamics and the response of CLIMBER-2. Other concepts, e.g. the idea of an intrinsic
1470-year mode, are far less applicable to explain the response of CLIMBER-2.
[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