Global reorganization of deep-sea circulation and carbon storage after the last ice age.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36383653.
- Also identified by DOI 10.1126/sciadv.abq5434 and PMC identifier 9668286.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Using new and published marine fossil radiocarbon (<sup>14</sup>C/C) measurements, a tracer uniquely sensitive to circulation and air-sea gas exchange, we establish several benchmarks for Atlantic, Southern, and Pacific deep-sea circulation and ventilation since the last ice age. We find the most <sup>14</sup>C-depleted water in glacial Pacific bottom depths, rather than the mid-depths as they are today, which is best explained by a slowdown in glacial deep-sea overturning in addition to a "flipped" glacial Pacific overturning configuration. These observations cannot be produced by changes in air-sea gas exchange alone, and they underscore the major role for changes in the overturning circulation for glacial deep-sea carbon storage in the vast Pacific abyss and the concomitant drawdown of atmospheric CO<sub>2</sub>.