| Lower atmospheric CO2 concentrations during the Last Glacial Maximum (LGM; 23.0‐18.0 ka) have been attributed to the sequestration of respired carbon in the ocean interior, yet the mechanism responsible for the release of this CO2 during the deglaciation remains uncertain. Here, we present calculations of vertical differences in oxygen and carbon isotopes (∆δ18O and ∆δ13C, respectively) from a depth transect of southwest Pacific Ocean sediment cores to reconstruct changes in water mass structure and CO2 storage. During the LGM, ∆δ18O indicates a more homogenous deep Pacific below 1100 m, whereas regional ∆δ13C elucidates greater sequestration of CO2 in two distinct layers: enhanced CO2 storage at intermediate depths between ~940 m and 1400 m, and... |
