Deglacial carbon cycle changes observed in a compilation of 127 benthic δ¹³C time series (20-6 ka)

We present a compilation of 127 time series δ¹³C records from Cibicides wuellerstorfi spanning the last deglaciation (20-6 ka) which is well-suited for reconstructing large-scale carbon cycle changes, especially for comparison with isotope-enabled carbon cycle models. The age models for the δ¹³C records are derived from regional planktic radiocarbon compilations (Stern and Lisiecki, 2014). The δ¹³C records were stacked in nine different regions and then combined using volume-weighted averages to create intermediate, deep, and global δ¹³C stacks. These benthic δ¹³C stacks are used to reconstruct changes in the size of the terrestrial biosphere and deep ocean carbon storage. The timing of change in global mean δ¹³C is interpreted to indicate terrestrial biosphere expansion from 19-6 ka. The δ¹³C gradient between the intermediate and deep ocean, which we interpret as a proxy for deep ocean carbon storage, matches the pattern of atmospheric CO₂ change observed in ice core records. The presence of signals associated with the terrestrial biosphere and atmospheric CO₂ indicates that the compiled δ¹³C records have sufficient spatial coverage and time resolution to accurately reconstruct large-scale carbon cycle changes during the glacial termination.