Relative Timing of Deglacial Climate Events in Antarctica and Greenland
Vin Morgan,1*
Marc Delmotte,23*
Tas van Ommen,1
Jean Jouzel,3
Jérôme Chappellaz,2
Suenor Woon,1
Valérie Masson-Delmotte,3
Dominique Raynaud2
The last deglaciation was marked by large, hemispheric,
millennial-scale climate variations: the Bølling-Allerød and Younger Dryas periods in the north, and the Antarctic Cold Reversal in the
south. A chronology from the high-accumulation Law Dome East Antarctic
ice core constrains the relative timing of these two events and
provides strong evidence that the cooling at the start of the Antarctic
Cold Reversal did not follow the abrupt warming during the northern
Bølling transition around 14,500 years ago. This result suggests that
southern changes are not a direct response to abrupt changes in North
Atlantic thermohaline circulation, as is assumed in the conventional
picture of a hemispheric temperature seesaw.
1 Antarctic Cooperative Research Centre and
Australian Antarctic Division, GPO Box 252-80, Hobart, Tasmania,
Australia.
2 CNRS/Laboratoire de Glaciologie et
Geophysique de l'Environment, 54 Rue Molière, B.P. 96, 38402 St.
Martin d'Hères Cedex, France.
3 Institut
Pierre-Simon Laplacer Laboratoire des Sciences du Climat et
L'Environment, Unite Mixte de Recherche Commissariat à
l'Energie Atomique-CNRS 1572, l'Orme des Merisiers, CEA Saclay, 91191 Gif sur Yvette Cedex, France.
*
These authors contributed equally to this work.
Present address: CNRS/Institut de Physique du Globe de
Paris, Laboratoire de Cosmochimie et Géochimie, 4 place Jussieu
tour 14, 3ème ètage, 75252 Paris Cedex 05, France.
To whom correspondence should be addressed. E-mail:
tas.van.ommen{at}utas.edu.au
