Recent reduced abyssal overturning and ventilation in the Australian Antarctic Basin

Kathryn L. Gunn (), Stephen R. Rintoul, Matthew H. England and Melissa M. Bowen
Additional contact information
Kathryn L. Gunn: CSIRO Environment
Stephen R. Rintoul: CSIRO Environment
Matthew H. England: University of New South Wales
Melissa M. Bowen: University of Auckland

Nature Climate Change, 2023, vol. 13, issue 6, 537-544

Abstract: Abstract Dense water formed near Antarctica, known as Antarctic bottom water (AABW), drives deep ocean circulation and supplies oxygen to the abyssal ocean. Observations show that AABW has freshened and contracted since the 1960s, yet the drivers of these changes and their impact remain uncertain. Here, using observations from the Australian Antarctic Basin, we show that AABW transport reduced by 4.0 Sv between 1994 and 2009, during a period of strong freshening on the continental shelf. An increase in shelf water salinity between 2009 and 2018, previously linked to transient climate variability, drove a partial recovery (2.2 Sv) of AABW transport. Over the full period (1994 to 2017), the net slowdown of −0.8 ± 0.5 Sv decade−1 thinned well-oxygenated layers, driving deoxygenation of −3 ± 2 μmol kg−1 decade−1. These findings demonstrate that freshening of Antarctic shelf waters weakens the lower limb of the abyssal overturning circulation and reduces deep ocean oxygen content.

Date: 2023
References: View complete reference list from CitEc
Citations: View citations in EconPapers (5)

Downloads: (external link)
https://www.nature.com/articles/s41558-023-01667-8 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcli:v:13:y:2023:i:6:d:10.1038_s41558-023-01667-8

Ordering information: This journal article can be ordered from
https://www.nature.com/nclimate/

DOI: 10.1038/s41558-023-01667-8

Access Statistics for this article

Nature Climate Change is currently edited by Bronwyn Wake

More articles in Nature Climate Change from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().