Relative timing of precipitation and ocean circulation changes in the western equatorial Atlantic over the last 45 kyr

Abstract. Thanks to its optimal location on the northern Brazilian margin, core MD09-3257 records both ocean circulation and atmospheric changes. The latter occur locally in the form of increased rainfall on the adjacent continent during the cold intervals recorded in Greenland ice and northern Nort...

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Bibliographic Details
Main Authors: Waelbroeck, Claire (Author) , Lippold, Jörg (Author)
Format: Article (Journal)
Language:English
Published: 18 September 2018
In: Climate of the past
Year: 2018, Volume: 14, Issue: 9, Pages: 1315-1330
ISSN:1814-9332
DOI:10.5194/cp-14-1315-2018
Online Access:Verlag, Volltext: https://doi.org/10.5194/cp-14-1315-2018
Verlag, Volltext: https://www.clim-past.net/14/1315/2018/
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Author Notes:Claire Waelbroeck, Sylvain Pichat, Evelyn Böhm, Bryan C. Lougheed, Davide Faranda, Mathieu Vrac, Lise Missiaen, Natalia Vazquez Riveiros, Pierre Burckel, Jörg Lippold, Helge W. Arz, Trond Dokken, François Thil, and Arnaud Dapoigny
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Summary:Abstract. Thanks to its optimal location on the northern Brazilian margin, core MD09-3257 records both ocean circulation and atmospheric changes. The latter occur locally in the form of increased rainfall on the adjacent continent during the cold intervals recorded in Greenland ice and northern North Atlantic sediment cores (i.e., Greenland stadials). These rainfall events are recorded in MD09-3257 as peaks in ln(Ti ∕ Ca). New sedimentary Pa ∕ Th data indicate that mid-depth western equatorial water mass transport decreased during all of the Greenland stadials of the last 40 kyr. Using cross-wavelet transforms and spectrogram analysis, we assess the relative phase between the MD09-3257 sedimentary Pa ∕ Th and ln(Ti ∕ Ca) signals. We show that decreased water mass transport between a depth of -1300 and 2300 m in the western equatorial Atlantic preceded increased rainfall over the adjacent continent by 120 to 400 yr at Dansgaard–Oeschger (D–O) frequencies, and by 280 to 980 yr at Heinrich-like frequencies.
Item Description:Gesehen am 15.04.2019
Physical Description:Online Resource
ISSN:1814-9332
DOI:10.5194/cp-14-1315-2018