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Millennial and sub-millennial scale climatic variations recorded in polar ice cores over the last glacial period
E. Capron1, A. Landais1, J. Chappellaz2, A. Schilt3, D. Buiron2, D. Dahl-Jensen4, S. J. Johnsen4, J. Jouzel1, B. Lemieux-Dudon2, L. Loulergue2, M. Leuenberger3, V. Masson-Delmotte1, H. Meyer5, H. Oerter5, and B. Stenni6
1Institut Pierre-Simon Laplace/Laboratoire des Sciences du Climat et de l'Environnement, CEA-UMR INSU/CNRS 8212-UVSQ, 91191 Gif-sur-Yvette, France
2Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS-UJF, 38400 St Martin d'Hères, France
3Climate and Environmental Physics, Physics Institute, and Oeschger Centre for Climate Change Research, University of Bern, Sidlerstr. 5, 3012 Bern, Switzerland
4Centre for Ice and Climate, Niels Bohr Institute, Univ. of Copenhagen, Juliane Maries Vej 30, 2100, Copenhagen, Denmark
5Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, P.O. Box 120161, 27515, Bremerhaven, Germany
6University of Trieste, Department of Geosciences, Via E. Weiss 2, 34127 Trieste, Italy
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Abstract. Since its discovery in Greenland ice cores, the millennial scale climatic
variability of the last glacial period has been increasingly documented at
all latitudes with studies focusing mainly on Marine Isotopic Stage 3 (MIS 3; 28–60 thousand of years before present, hereafter ka) and characterized
by short Dansgaard-Oeschger (DO) events. Recent and new results obtained on
the EPICA and NorthGRIP ice cores now precisely describe the rapid
variations of Antarctic and Greenland temperature during MIS 5 (73.5–123 ka),
a time period corresponding to relatively high sea level. The results
display a succession of abrupt events associated with long Greenland
InterStadial phases (GIS) enabling us to highlight a sub-millennial scale
climatic variability depicted by (i) short-lived and abrupt warming events
preceding some GIS (precursor-type events) and (ii) abrupt warming events at
the end of some GIS (rebound-type events). The occurrence of these
sub-millennial scale events is suggested to be driven by the insolation at
high northern latitudes together with the internal forcing of ice sheets.
Thanks to a recent NorthGRIP-EPICA Dronning Maud Land (EDML) common
timescale over MIS 5, the bipolar sequence of climatic events can be
established at millennial to sub-millennial timescale. This shows that for
extraordinary long stadial durations the accompanying Antarctic warming
amplitude cannot be described by a simple linear relationship between the
two as expected from the bipolar seesaw concept. We also show that when ice
sheets are extensive, Antarctica does not necessarily warm during the whole
GS as the thermal bipolar seesaw model would predict, questioning the
Greenland ice core temperature records as a proxy for AMOC changes
throughout the glacial period.
Final Revised Paper (PDF, 2330 KB) Discussion Paper (CPD) Special Issue
Citation: Capron, E., Landais, A., Chappellaz, J., Schilt, A., Buiron, D., Dahl-Jensen, D., Johnsen, S. J., Jouzel, J., Lemieux-Dudon, B., Loulergue, L., Leuenberger, M., Masson-Delmotte, V., Meyer, H., Oerter, H., and Stenni, B.: Millennial and sub-millennial scale climatic variations recorded in polar ice cores over the last glacial period, Clim. Past, 6, 345-365, doi:10.5194/cp-6-345-2010, 2010. Bibtex EndNote Reference Manager XML
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