Portion of Figure 1. Dome C CH4 (purple line), N2O (red line), and dD (black line).
Click for full image.
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Atmospheric methane and nitrous oxide of the late Pleistocene from Antarctic ice cores
Science
Vol. 310, Issue 5752, pp. 1317-1321, 25 November 2005.
Renato Spahni1, Jérôme Chappellaz2, Thomas F. Stocker1,
Laetitia Loulergue2, Gregor Hausammann1, Kenji Kawamura1,
Jacqueline Flückiger1, Jakob Schwander1, Dominique Raynaud2,
Valérie Masson-Delmotte3, Jean Jouzel3
1
Climate and Environmental Physics, Physics Institute,
University of Bern, Sidlerstrasse 5, CH-3012 Bern,
Switzerland.
2
Laboratoire de Glaciologie et de Géophysique
de l'Environnement (CNRS), 54 Rue
Molières, 38402 St. Martin d'Hères Cedex, France.
3
Institut Pierre Simon Laplace/Laboratoire des
Sciences du Climat et de l'Environnement, CEA-CNRS
1572, CE Saclay, Orme des Merisiers, 91191 Gif-sur-
Yvette, France.
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ABSTRACT:
The European Project for Ice Coring in Antarctica Dome C ice core enables us to extend
existing records of atmospheric methane (CH4) and nitrous oxide (N2O) back to 650,000
years before the present. A combined record of CH4 measured along the Dome C and the
Vostok ice cores demonstrates, within the resolution of our measurements, that
preindustrial concentrations over Antarctica have not exceeded 773 +/- 15 ppbv
(parts per billion by volume) during the past 650,000 years. Before 420,000 years ago,
when interglacials were cooler, maximum CH4 concentrations were only about 600 ppbv,
similar to lower Holocene values. In contrast, the N2O record shows maximum concentrations
of 278 +/- 7 ppbv, slightly higher than early Holocene values.
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