Articles | Volume 6, issue 3
Clim. Past, 6, 295–303, 2010
https://doi.org/10.5194/cp-6-295-2010

Special issue: Retrospective views on our planet's future – PAGES Open...

Clim. Past, 6, 295–303, 2010
https://doi.org/10.5194/cp-6-295-2010

  05 May 2010

05 May 2010


Patterns of millennial variability over the last 500 ka

M. Siddall1, E. J. Rohling2, T. Blunier3, and R. Spahni4 M. Siddall et al.
  • 1Department of Earth Science, University of Bristol, Bristol, UK
  • 2National Oceanography Centre, Southampton, Southampton, UK
  • 3Centre for Ice & Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
  • 4Climate and Environmental Physics and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland

Abstract. Millennial variability is a robust feature of many paleoclimate records, at least throughout the last several glacial cycles. Here we use the mean signal from Antarctic climate events 1 to 4 to probe the EPICA Dome C temperature proxy reconstruction through the last 500 ka for similar millennial-scale events. We find that clusters of millennial events occurred in a regular fashion over half of the time during this with a mean recurrence interval of 21 kyr. We find that there is no consistent link between ice-rafted debris deposition and millennial variability. Instead we speculate that changes in the zonality of atmospheric circulation over the North Atlantic form a viable alternative to freshwater release from icebergs as a trigger for millennial variability. We suggest that millennial changes in the zonality of atmospheric circulation over the North Atlantic are linked to precession via sea-ice feedbacks and that this relationship is modified by the presence of the large, Northern Hemisphere ice sheets during glacial periods.