Details

Autor(en) / Beteiligte

• Bauska, Thomas K.
• Baggenstos, Daniel
• Brook, Edward J.
• Mix, Alan C.
• Marcott, Shaun A.
• Petrenko, Vasilii V.
• Schaefer, Hinrich
• Severinghaus, Jeffrey P.
• Lee, James E.

Titel

Carbon isotopes characterize rapid changes in atmospheric carbon dioxide during the last deglaciation

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 2016-03, Vol.113 (13), p.3465-3470

Ort / Verlag

United States: National Academy of Sciences

Erscheinungsjahr

2016

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• An understanding of the mechanisms that control CO₂ change during glacial–interglacial cycles remains elusive. Here we help to constrain changing sources with a high-precision, high-resolution deglacial record of the stable isotopic composition of carbon in CO₂ (δ13C-CO₂) in air extracted from ice samples from Taylor Glacier, Antarctica. During the initial rise in atmospheric CO₂ from 17.6 to 15.5 ka, these data demarcate a decrease in δ13C-CO₂, likely due to a weakened oceanic biological pump. From 15.5 to 11.5 ka, the continued atmospheric CO₂ rise of 40 ppm is associated with small changes in δ13C-CO₂, consistent with a nearly equal contribution from a further weakening of the biological pump and rising ocean temperature. These two trends, related to marine sources, are punctuated at 16.3 and 12.9 ka with abrupt, century-scale perturbations in δ13C-CO₂ that suggest rapid oxidation of organic land carbon or enhanced air–sea gas exchange in the Southern Ocean. Additional century-scale increases in atmospheric CO₂ coincident with increases in atmospheric CH₄ and Northern Hemisphere temperature at the onset of the Bølling (14.6–14.3 ka) and Holocene (11.6–11.4 ka) intervals are associated with small changes in δ13C-CO₂, suggesting a combination of sources that included rising surface ocean temperature.