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

TitleCarbon isotopes characterize rapid changes in atmospheric carbon dioxide during the last deglaciation
Publication TypeJournal Article
Year of Publication2016
AuthorsBauska T.K, Baggenstos D, Brook E.J, Mix A.C, Marcott S.A, Petrenko VV, Schaefer H, Severinghaus JP, Lee J.E
JournalProceedings of the National Academy of Sciences of the United States of America
Volume113
Pagination3465-3470
Date Published2016/03
Type of ArticleArticle
ISBN Number0027-8424
Accession NumberWOS:000372876400038
Keywordsatmospheric co2; carbon cycle; circulation; co2 rise; cycle; deglaciation; dust; glacial maximum; ice core; ice cores; last; north-atlantic; paleoclimate; sea-ice; southern-ocean; ventilation
Abstract

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 (delta C-13-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 delta C-13-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 delta C-13-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 delta C-13-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 Bolling (14.6-14.3 ka) and Holocene (11.6-11.4 ka) intervals are associated with small changes in delta C-13-CO2, suggesting a combination of sources that included rising surface ocean temperature.

DOI10.1073/pnas.1513868113
Student Publication: 
No