|Title||Carbon isotopes characterize rapid changes in atmospheric carbon dioxide during the last deglaciation|
|Publication Type||Journal Article|
|Year of Publication||2016|
|Authors||Bauska T.K, Baggenstos D, Brook E.J, Mix A.C, Marcott S.A, Petrenko VV, Schaefer H, Severinghaus JP, Lee J.E|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Type of Article||Article|
|Keywords||atmospheric co2; carbon cycle; circulation; co2 rise; cycle; deglaciation; dust; glacial maximum; ice core; ice cores; last; north-atlantic; paleoclimate; sea-ice; southern-ocean; ventilation|
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.