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  • Evaluating the Glacial‐Deglacial Carbon Respiration and Ventilation Change Hypothesis as a Mechanism for Changing Atmospheric CO 2
Title: Evaluating the Glacial‐Deglacial Carbon Respiration and Ventilation Change Hypothesis as a Mechanism for Changing Atmospheric CO 2
Abstract The prevailing hypothesis to explain pCO2rise at the last glacial termination calls upon enhanced ventilation of excess respired carbon that accumulated in the deep sea during the glacial. Recent studies argue lower [O2] in the glacial ocean is indicative of increased carbon respiration. The magnitude of [O2] depletion was 100–140 µ mol/kg at the glacial maximum. Because respiration is coupled toδ13C of dissolved inorganic carbon (DIC), [O2] depletion of 100–140 µ mol/kg from carbon respiration would lower deep waterδ13CDICby ∼1‰ relative to surface water. Prolonged sequestration of respired carbon would also lower the amount of14C in the deep sea. We show that Pacific Deep Waterδ13CDICdid not decrease relative to the surface ocean and Δ14C was only ∼50‰ lower during the late glacial. Model simulations of the hypothesized ventilation change during deglaciation lead to large increases inδ13CDIC, Δ14C, andε14C that are not recorded in observations.  more » « less
Award ID(s):
1904433
PAR ID:
10442879
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
DOI PREFIX: 10.1029
Date Published:
Journal Name:
Geophysical Research Letters
Volume:
48
Issue:
3
ISSN:
0094-8276
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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