Abstract203 – University of Copenhagen

A continuous record of temperature evolution over a sequence of Dansgaard-Oeschger events during Marine Isotopic Stage 4 (76 to 62 kyr BP) 

Geophysical Research Letters, Vol. 31, L22211, doi: 10.1029/2004GL021193, 2004 

A. Landais, V. Masson-Delmotte, J. Jouzel and N. Caillon
Institut Pierre-Simon Laplace/Laboratoire des Sciences du Climat et de l'Environnement, CEA Saclay, Gif-sur-Yvette, France
J.M. Barnola and J. Chappellaz
Laboratoire de Glaciologie Geophysique de l'Environnement, Centre National de la Recherche Scientifique, Saint Martin d'Heres, France
C. Huber and M. Leuenberger
Physics Institute, University of Bern, Bern, Switzerland
S.J. Johnsen
Geofysisk Afdeling, Niels Bohr Instituttet for Astronomi, Fysik og Geofysik, Københavns Universitet

Our knowledge of the temperature evolution over Greenland during Dansgaard-Oeschger events (DO) is currently qualitatively described through the water isotopic profile. Using two independent paleothermometry methods, one based on air isotopic measurements and the other on the combined measurements of water isotopes (δD and δ18O), we show a complete and quantitative reconstruction of temperature at the NorthGRIP site over the period 76 to 62 kyr BP (DO 18, 19 and 20). We confirm that the associated warmings are larger than those conventionally depicted by the water isotopes (11oC, 16oC and 11oC for DO 18, 19 and 20). Secondly, we demonstrate that the relationship between temperature and δ18O varies rapidly during the last glacial period, even over a DO. Finally, our temperature reconstruction over DO 19 agrees well with that predicted from simple climate models linking the DO to iceberg discharges.