Deglacial Ventilation Changes in the Deep Southwest Pacific

Processes underlying changes in the oceanic carbon storage during Last Glacial Maximum and subsequent deglaciation are not fully understood. Here, we present a new high-resolution radiocarbon reconstruction (expressed as ?14R) at depth of modern Lower Circumpolar Deep Water from Pacific Sector Southern Ocean. Our record shows ?14R increases Heinrich Stadial 1 Younger Dryas that agree with deep-to-shallow transfer old Ocean these two periods. also shows, for first time, clear ?80‰ decline Antarctic Cold Reversal (ACR), indicating development poorly ventilated conditions deep Southwest Pacific. These consistent increased sea-ice associated stratification between Upper Waters. This enhanced South possibly facilitated greater ocean interior ACR, effectively limiting CO2 release contributing to atmospheric plateau observed ice cores time.