Centennial to multi-millennial signals in the atmospheric radiocarbon record during the Holocene

HR: 08:30h
AN: U41B-03 [Abstracts]
TI: Centennial to multi-millennial signals in the atmospheric radiocarbon record during the Holocene - a solar link from tree-rings
AU: * Kromer, B
EM: bernd.kromer@iup.uni-heidelberg.de
AF: Heidelberg Academy of Sciences , INF 229 , Heidelberg, D-69120 Germany
AU: Claussen, M
EM: Martin.Claussen@pik-potsdam.de
AF: Potsdam Institute for Climate Impact Research, Telegrafenberg A31, Potsdam, D-14473 Germany
AU: Friedrich, M
EM: michaelf@Uni-Hohenheim.de
AF: University Hohenheim, Institute of Botany-210, Stuttgart, D-70595 Germany
AU: Latuske, N
EM: nicolas.latuske@iup.uni-heidelberg.de
AF: Heidelberg Academy of Sciences , INF 229 , Heidelberg, D-69120 Germany
AU: Latuske, N
EM: nicolas.latuske@iup.uni-heidelberg.de
AF: InsInstitute of Environmental Physics University of Heidelberg , Institute of Environmental Physics INF 229, Heidelberg, D-69120 Germany
AU: L〔en, M
EM: lueken@pik-potsdam.de
AF: InsInstitute of Environmental Physics University of Heidelberg , Institute of Environmental Physics INF 229, Heidelberg, D-69120 Germany
AU: L〔en, M
EM: lueken@pik-potsdam.de
AF: Potsdam Institute for Climate Impact Research, Telegrafenberg A31, Potsdam, D-14473 Germany
AB: Commonly, fluctuations of the atmospheric 14C level are taken as an indicator of solar variability. This concept is based on the well understood physical relation between 14C production from cosmic ray flux and heliomagnetic and geomagnetic shielding of the earth, on one hand, and on the observed close correlation of sunspot numbers (SSN), and other indicators of solar activity, and D14C over the past three centuries, on the other hand. Although there are good arguments for considering solar activity changes to dominate decadal to multi-centennial signals in the 14C record, it remains an open question as to how much carbon system changes, and the changes in the relative distribution of 14C among the major reservoirs contribute to 14C variations. In our contribution we address this questions focussing on the tree-ring based 14C record, now reaching back to 12,400 years BP. We discuss spectral features of the record, and compare them to results obtained from the 10Be record in ice cores. Using possible range of changes in the meridional overturning circulation of the North Atlantic we calculate their contribution to the 14C signals. We show the response of forcing the CLIMBER-2 model with irradiance variations scaled by the 14C anomalies. We report on our ongoing work to relate climate proxies in tree-ring parameters to intervals of strong 14C anomalies in the Holocene.
DE: 3344 Paleoclimatology
DE: 4221 Dendrochronology
DE: 1650 Solar variability
SC: Union [U]
MN: 2004 AGU Fall Meeting