DOI: 10.1016/j.palaeo.2013.12.005
论文题名: Variability of the Brazil Current during the late Holocene
作者: Chiessi C.M. ; Mulitza S. ; Groeneveld J. ; Silva J.B. ; Campos M.C. ; Gurgel M.H.C.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 415 起始页码: 28
结束页码: 36
语种: 英语
英文关键词: Late Quaternary
; Mg/Ca
; Planktonic foraminifera
; South Atlantic
; Stable oxygen isotopes
; Western boundary current
英文摘要: 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°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. °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 cyclicity 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. © 2013 Elsevier B.V. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69175
Appears in Collections: 过去全球变化的重建
There are no files associated with this item.
作者单位: School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil; MARUM - Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany; Institute of Geosciences, University of São Paulo, São Paulo, Brazil
Recommended Citation:
Chiessi C.M.,Mulitza S.,Groeneveld J.,et al. Variability of the Brazil Current during the late Holocene[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,415