Abstract

The millennial-scale variability of the Atlantic Meridional Overturning Circulation (AMOC) is well documented for the last glacial termination and beyond. Despite its importance for the climate system, the evolution of the South Pacific overturning circulation (SPOC) is by far less well understood. A recently published study highlights the potential applicability of the 231Pa/230Th-proxy in the Pacific. Here, we present five sedimentary down-core profiles of 231Pa/230Th-ratios measured on a depth transect from the Pacific sector of the Southern Ocean to test this hypothesis using downcore records. Our data are consistent with an increase in SPOC as early as 20 ka that peaked during Heinrich Stadial 1. The timing indicates that the SPOC did not simply react to AMOC changes via the bipolar seesaw but were triggered via Southern Hemisphere processes.

Details

Title
Deglacial patterns of South Pacific overturning inferred from 231Pa and 230Th
Author
Ronge, Thomas A 1 ; Lippold Jörg 2 ; Geibert, Walter 1 ; Jaccard, Samuel L 3 ; Mieruch-Schnülle Sebastian 1 ; Finn, Süfke 2 ; Tiedemann Ralf 4 

 Alfred-Wegener-Institut Helmholtz Zentrum für Polar-und Meeresforschung, Department of Marine Geology, Bremerhaven, Germany (GRID:grid.10894.34) (ISNI:0000 0001 1033 7684) 
 Universität Heidelberg, Institut für Geowissenschaften, Heidelberg, Germany (GRID:grid.7700.0) (ISNI:0000 0001 2190 4373) 
 Universität Bern, Institut für Geologie & Oeschger Center for Climate Change Research, Bern, Switzerland (GRID:grid.5734.5) (ISNI:0000 0001 0726 5157); University of Lausanne, Institute of Earth Sciences, Lausanne, Switzerland (GRID:grid.9851.5) (ISNI:0000 0001 2165 4204) 
 Alfred-Wegener-Institut Helmholtz Zentrum für Polar-und Meeresforschung, Department of Marine Geology, Bremerhaven, Germany (GRID:grid.10894.34) (ISNI:0000 0001 1033 7684); Universität Bremen, MARUM Center for Marine Environmental Sciences, Bremen, Germany (GRID:grid.7704.4) (ISNI:0000 0001 2297 4381) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2581966600
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.