Destabilisation of the Subpolar North Atlantic prior to the Little Ice Age.

Autor: Arellano-Nava B; Global Systems Institute and Geography Department, University of Exeter, Exeter, UK., Halloran PR; Global Systems Institute and Geography Department, University of Exeter, Exeter, UK. P.Halloran@exeter.ac.uk., Boulton CA; Global Systems Institute and Geography Department, University of Exeter, Exeter, UK., Scourse J; College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, UK., Butler PG; College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, UK., Reynolds DJ; College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, UK., Lenton TM; Global Systems Institute and Geography Department, University of Exeter, Exeter, UK.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2022 Aug 25; Vol. 13 (1), pp. 5008. Date of Electronic Publication: 2022 Aug 25.
DOI: 10.1038/s41467-022-32653-x
Abstrakt: The cooling transition into the Little Ice Age was the last notable shift in the climate system prior to anthropogenic global warming. It is hypothesised that sea-ice to ocean feedbacks sustained an initial cooling into the Little Ice Age by weakening the subpolar gyre circulation; a system that has been proposed to exhibit bistability. Empirical evidence for bistability within this transition has however been lacking. Using statistical indicators of resilience in three annually-resolved bivalve proxy records from the North Icelandic shelf, we show that the subpolar North Atlantic climate system destabilised during two episodes prior to the Little Ice Age. This loss of resilience indicates reduced attraction to one stable state, and a system vulnerable to an abrupt transition. The two episodes preceded wider subpolar North Atlantic change, consistent with subpolar gyre destabilisation and the approach of a tipping point, potentially heralding the transition to Little Ice Age conditions.
(© 2022. The Author(s).)
Databáze: MEDLINE
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