Solar Variability Reflected in 10Be Concentrations in the Summit Ice Core from the Holocene Period and Comparisons with 14C- and Historical Sunspot Data
Abstract
Cosmogenic isotopes 10Be and 14C reflect certain aspects of solar variability in terrestrial archives. The paper presents an analysis of 10Beryllium data from the SUMMIT ice core during the holocene period and comparisons with the STUIVER 14C record and with historical sunspot data. Longer cycles with about 88 years period length and 208 years could be identified by means of spectral analysis and bandfilterings. For the comparison of the 10Be data with the 14C data a 14C model of BEER &MUSCHELER is used. This allows a rectification of the 10Be time scale during some time windows in the holocene. The improvement of the 10Be time scale could be confirmed by the better spectral contrast of the identified 88- and 208-year solar cycles. Also the 11-year SCHWABE cycle could be identified in form of a spectral peak during periods where the sampling rate is sufficiently dense. In some cases comparisons with corresponding 14C data allow us to identify and to reconstruct single 11-year SCHWABE cycles and groups of contiguous cycles. The shapes of these cycles could be modelled and compared with historical sunspot cycles.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA....12849M