Journal cover Journal topic
Climate of the Past An interactive open-access journal of the European Geosciences Union
Clim. Past, 10, 63-77, 2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
14 Jan 2014
Hindcasting the continuum of Dansgaard–Oeschger variability: mechanisms, patterns and timing
L. Menviel1,2, A. Timmermann3, T. Friedrich3, and M. H. England1,2 1Climate Change Research Centre, University of New South Wales, Sydney, Australia
2ARC Centre of Excellence in Climate System Science, Australia
3International Pacific Research Center, University of Hawaii, Honolulu, USA
Abstract. Millennial-scale variability associated with Dansgaard–Oeschger events is arguably one of the most puzzling climate phenomena ever discovered in paleoclimate archives. Here, we set out to elucidate the underlying dynamics by conducting a transient global hindcast simulation with a 3-D intermediate complexity earth system model covering the period 50 to 30 ka BP. The model is forced by time-varying external boundary conditions (greenhouse gases, orbital forcing, and ice-sheet orography and albedo) and anomalous North Atlantic freshwater fluxes, which mimic the effects of changing northern hemispheric ice volume on millennial timescales. Together these forcings generate a realistic global climate trajectory, as demonstrated by an extensive model/paleo data comparison. Our results are consistent with the idea that variations in ice-sheet calving and subsequent changes of the Atlantic Meridional Overturning Circulation were the main drivers for the continuum of glacial millennial-scale variability seen in paleorecords across the globe.

Citation: Menviel, L., Timmermann, A., Friedrich, T., and England, M. H.: Hindcasting the continuum of Dansgaard–Oeschger variability: mechanisms, patterns and timing, Clim. Past, 10, 63-77,, 2014.
Publications Copernicus