Antarctic evidence for an abrupt northward shift of the Southern Hemisphere westerlies at 32 ka BP.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37669925.
- Also identified by DOI 10.1038/s41467-023-40951-1 and PMC identifier 10480229.
- 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
High-resolution ice core records from coastal Antarctica are particularly useful to inform our understanding of environmental changes and their drivers. Here, we present a decadally resolved record of sea-salt sodium (a proxy for open-ocean area) and non-sea salt calcium (a proxy for continental dust) from the well-dated Roosevelt Island Climate Evolution (RICE) core, focusing on the time period between 40-26 ka BP. The RICE dust record exhibits an abrupt shift towards a higher mean dust concentration at 32 ka BP. Investigating existing ice-core records, we find this shift is a prominent feature across Antarctica. We propose that this shift is linked to an equatorward displacement of Southern Hemisphere westerly winds. Subsequent to the wind shift, data suggest a weakening of Southern Ocean upwelling and a decline of atmospheric CO<sub>2</sub> to lower glacial values, hence making this shift an important glacial climate event with potentially important insights for future projections.