Accelerated drawdown of meridional overturning in the late-glacial Atlantic triggered by transient pre-H event freshwater perturbation [Letter]

Hall, Ian Robert ORCID: https://orcid.org/0000-0001-6960-1419, Moran, S. B., Zahn, Rainer, Knutz, Paul C., Shen, C.-C. and Edwards, R. L. 2006. Accelerated drawdown of meridional overturning in the late-glacial Atlantic triggered by transient pre-H event freshwater perturbation [Letter]. Geophysical research letters 33 (16) , L16616. 10.1029/2006GL026239

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Abstract

Abrupt decreases of the Atlantic meridional overturning circulation (MOC) during the Late Pleistocene have been directly linked to catastrophic discharges of glacimarine freshwater, triggering disruption of northward marine heat transport and causing global climate changes. Here we provide measurements of excess sedimentary 231Pa/230Th from a high-accumulation sediment drift deposit in the NE Atlantic that record a sequence of sudden variations in the rate of MOC, associated deep ocean ventilation and surface-ocean climatology. The data series reveal a sequential decrease in the MOC rate at ∼18.0 ka BP ago that coincides with only transient and localized freshwater inputs. This change represents a substantial, though not total, cessation in MOC that predates the major Heinrich (H1) meltwater event by at least 1,200 years. These results highlight the potential of targeted freshwater perturbations in promoting substantial MOC changes without a direct linking with catastrophic freshwater surges.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Earth and Environmental Sciences
Additional Information:	Publisher's copyright requirements "Permission to Deposit an Article in an Institutional Repository. Adopted by Council 13 December 2009. AGU allows authors to deposit their journal articles if the version is the final published citable version of record, the AGU copyright statement is clearly visible on the posting, and the posting is made 6 months after official publication by the AGU." See http://www.agu.org/pubs/authors/usage_permissions.shtml
Publisher:	American Geophysical Union
ISSN:	00948276
Last Modified:	16 May 2023 09:28
URI:	https://orca.cardiff.ac.uk/id/eprint/1293

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