Evidence of 550-year and 1000-year cyclicities in North Atlantic circulation patterns during the Holocene

• Published in: The Holocene
• Main Authors: Chapman, Mark R., Shackleton, Nicholas J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: SAGE Publications 2000
• Subjects: Greenland; NADW; North Atlantic Deep Water; North Atlantic
• Online Access: http://dx.doi.org/10.1191/095968300671253196; http://journals.sagepub.com/doi/pdf/10.1191/095968300671253196

Sedimentological colour data obtained from North Atlantic deep-sea sediment core NEAP15K pro vide a continuous climate record for the last 11500 yr with a mean sampling interval of <15 yr. Variations in sediment lightness, a proxy for changes in North Atlantic Deep Water (NADW) circulation, are characterized by high-frequency fluctuations with periodicities equivalent to 550 and 1000 yr, as well as a <1600-yr cyclicity comparable to that reported in other studies of Holocene climate. Cross-spectral analysis suggests that the 550-yr and 1000-yr cyclical variations in NADW circulation were coherent with fluctuations in atmospheric con ditions over Greenland, where both these periodicities have been identified previously in the Holocene GISP2 d 18 O record (Stuiver et al., 1995). A similar statistical comparison provides evidence that high-frequency (550-yr) variability in NADW circulation patterns may have been linked to short-term variations in atmospheric 14 C values during the Holocene. In general, NADW production was lower and 14C levels were higher when colder climatic conditions prevailed. These results imply that the pattern of NADW production has been a significant factor affecting centennial-to millennial-scale Holocene climate variability in the North Atlantic region.