Joint 900-year periodicity of Holocene climate in records from GISP2 and two sediment profiles west of the Barents shelf and the South China Sea

Different from most glacial time series and in contrast to a record of Bianchi and McCave (1999) no Dansgaard-Oeschger-style 1450-1550-y climate oscillations occur in the Holocene \delta¹⁸O temperature oscillations of the GISP2 ice core and in various Holocene proxy records which were measured on two hemipelagic sediment cores from both the lower continental slope west of the Barents shelf, 75° N (GIK 23258), and the northern slope of the South China Sea near Hong Kong (GIK 17940). Nevertheless, the Holocene records of GIK 23258 show distinct Holocene pulses of enhanced seasonal sea ice forma-tion and/or storminess on the Barents shelf. They led to cascades of cold, dense winter water down the continental slope and clear-cut maxima of coarse sediment fraction in core 23258, which follow a dominant 885-y period-icity in the early Holocene, later dropping to 840 years. A similar 890-y periodicity was first found in the GISP2 ice core, here ascribed to internal North Atlantic salinity perturbations (Schulz and Paul, 2001). On the other hand, the GISP2 temperature oscillations also parallel the ¹⁰Be accumulation rates as derived by Finkel and Nishiizumi (1997) and thus may result from solar forcing. Near Hong Kong the intensity of monsoon precipitation was dominated by a similar 950-y cycle which lagged the GISP2 signal by 250-400 years, indicating a high-latitude process control. Further solar forcing is recorded by significant deVriess (190-230 y) and Gleissberg (85-105 y) periodicities in the marine sediment records of the Holocene. Bianchi, G.G. and N. McCave (1999) Nature, 397, 515-517 Finkel, R.C. and K. Nishiizumi (1997) JGR, 102, 26,699-26,706 Schulz, M. and A. Paul (2001) in: W.H. Berger and G. Wefer (eds) Past climate and its significance for human history in NW Europe, the last 10,000 years. Springer Verlag, Berlin