Asynchrony of antartic and Greenland climate change during the last glacial period.

Nature vol 394, Aug. 20 1998

T. Blunier, J. Schwander, A. Dällenbach, B. Stauffer, T.F. Stocker
Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland.
J. Chappellaz, D. Raynaud,
Laboratoire de Glaciologie et de Geophysique de l'Environnement, Centre National de la Recherche Scientifique St. Martin d'Héres, France.
J. Jouzel
Laboratoire de Glaciologie et de Geophysique de l'Environnement, Centre National de la Recherche Scientifique St. Martin d'Héres, France.
and Laboratoire de Modélisation du Climat et de l'Environnement , Gif-Sur-Yvette, France.
H.B. Clausen, C.U. Hammer
Departement of Geophysics, The Niels Bohr Institute of Astronomy, Physics and Geophysics, University of Copenhagen..
S.J. Johnsen
Science Institute, University of Iceland, Reykjavik, also at Departement of Geophysics, The Niels Bohr Institute of Astronomy, Physics and Geophysics, University of Copenhagen .

ABSTRACT.
A central issue in climate dynamics is to understand how the Northern and Southern hemispheres are coupled during climate events. The strongest of the fast temperature changes observed in Greenland (so-called Dansgaard-Oeschger events) during the last glaciation have an analogue in the temperature record from Antarctica. A comparison of the global atmospheric concentration of methane as recorded in ice cores from Antarctica and Greenland permits a determination of the phase relationship (in leads or lags) of these temperature variations. Greenland warming events around 36 and 46 kyr before present lag their Antarctic counterpart by more than 1 kyr. On average, Antarctic climate change leeds that of Greenland by 1-2.5 kyr over the period 47-23 kyr before present.