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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Variability of the Brazil Current during the late Holocene

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Chiessi, Cristiano M. [1] ; Mulitza, Stefan [2] ; Groeneveld, Jeroen [2] ; Silva, Juliana B. [3] ; Campos, Marilia C. [1] ; Gurgel, Marcio H. C. [1]
Total Authors: 6
[1] Univ Sao Paulo, Sch Arts Sci & Humanities, Sao Paulo - Brazil
[2] Univ Bremen, MARUM Ctr Marine Environm Sci, D-28359 Bremen - Germany
[3] Univ Sao Paulo, Inst Geosci, Sao Paulo - Brazil
Total Affiliations: 3
Document type: Journal article
Web of Science Citations: 16

Our understanding of the centennial-scale variability of the Brazil Current (BC) during the late Holocene is elusive because of the lack of appropriate records. Here we used the Mg/Ca and oxygen isotopic composition of planktonic foraminifera from two marine sediment cores collected at 27 S and 33 degrees S off southeastern South America to assess the late Holocene variability in the upper water column of the BC. Our results show in phase fluctuations of up to 3 degrees C in sea surface temperatures (SST), and 0.8% in oxygen isotopic composition of surface sea water, a proxy for relative sea surface salinity (SSS). Time-series analyses of our records indicate a cyc.licity with a period of ca. 730 yr. We suggest that the observed cyclicity reflects variability in the strength of the BC associated to changes in the Atlantic meridional overturning circulation (AMOC). Positive (negative) SST and SSS anomalies are related to a strong (weak) BC and a weak (strong) AMOC. Moreover, periods of peak strength in the BC occur synchronously to a weak North Brazil Current, negative SST anomalies in the high latitudes of the North Atlantic, and positive (negative) precipitation anomalies over southeastern South America (equatorial Africa), further corroborating our hypothesis. This study shows a tight coupling between the variability of the BC and the high latitudes of the North Atlantic mediated by the AMOC even under late Holocene boundary conditions. (C) 2013 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 12/17517-3 - Response of the Western Atlantic Ocean to changes in the Atlantic meridional overturning circulation: from millennial to seasonal variability
Grantee:Cristiano Mazur Chiessi
Support type: Research Program on Global Climate Change - Young Investigators
FAPESP's process: 10/09983-9 - Sea surface temperature changes in the western South Atlantic and precipitation variability in southeastern South America since the Last Glacial Maximum
Grantee:Cristiano Mazur Chiessi
Support type: Regular Research Grants