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Deglacial Ventilation Changes in the Deep Southwest Pacific
Author(s) -
Dai Yuhao,
Yu Jimin,
Rafter Patrick
Publication year - 2021
Publication title -
paleoceanography and paleoclimatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.927
H-Index - 127
eISSN - 2572-4525
pISSN - 2572-4517
DOI - 10.1029/2020pa004172
Subject(s) - stadial , circumpolar deep water , oceanography , geology , deglaciation , younger dryas , deep sea , stratification (seeds) , radiocarbon dating , north atlantic deep water , circumpolar star , climatology , thermohaline circulation , holocene , paleontology , seed dormancy , botany , germination , dormancy , biology
Abstract Processes underlying changes in the oceanic carbon storage during the Last Glacial Maximum and the subsequent deglaciation are not fully understood. Here, we present a new high‐resolution radiocarbon reconstruction (expressed as δ 14 R) at the depth of the modern Lower Circumpolar Deep Water from the Pacific Sector of the Southern Ocean. Our record shows δ 14 R increases during Heinrich Stadial 1 and the Younger Dryas that agree with the deep‐to‐shallow transfer of old carbon in the Southern Ocean during these two periods. Our record also shows, for the first time, a clear ∼80‰ decline in δ 14 R during the Antarctic Cold Reversal (ACR), indicating the development of poorly ventilated conditions in the deep Southwest Pacific. These conditions are consistent with the increased Southern Ocean sea‐ice and associated stratification between Upper and Lower Circumpolar Deep Waters. This enhanced stratification in the deep South Pacific possibly facilitated greater carbon storage in the ocean interior during the ACR, effectively limiting oceanic CO 2 release and contributing to the atmospheric CO 2 plateau as observed in ice cores at that time.