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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.)

High-resolution Holocene South American monsoon history recorded by a speleothem from Botuvera Cave, Brazil

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Author(s):
Bernal, J. P. ; Cruz, Francisco W. ; Strikis, Nicolas M. ; Wang, Xianfeng ; Deininger, Michael ; Catunda, Maria Carolina A. ; Ortega-Obregon, C. ; Cheng, Hai ; Edwards, R. Lawrence ; Auler, Augusto S.
Total Authors: 10
Document type: Journal article
Source: Earth and Planetary Science Letters; v. 450, p. 186-196, SEP 15 2016.
Web of Science Citations: 23
Abstract

A Holocene stalagmite from Botuvera Cave, southeastern Brazil was analyzed by LA-ICPMS for Mg/Ca, Sr/Ca, Ba/Ca. The observed variability in the record was demonstrated to be modulated by prior calcite precipitation, and, thus, is interpreted to reflect monsoon intensity. We find that the calcite delta O-18 is strongly correlated with Sr/Ca, indicating that atmospheric circulation over South America and monsoon intensity have been tightly correlated throughout most of the Holocene, both directly responding to solar precession. Comparison with other contemporaneous high-resolution hydroclimate records reveals that SAMS has shown a degree of complexity during the Holocene not previously detected, with periods where the South American Convergence Zone (SACZ) expanded to cover most of the South American subcontinent, and coincident with periods of low-SST in the north Atlantic. We also detect periods where rainfall amount in northeastern and southeastern Brazil are markedly anti-phased, suggesting a north south migration of SACZ, which it appears to be mediated by solar irradiance. The high-resolution nature of our record allow us to examine the effect that Holocene climate anomalies had upon SAMS dynamics and hydroclimate in southeastern Brazil, in particular the 8.2 ka event and the Little Ice Age. In addition to confirm the internal structure of the events, we also detect the possible consequences of the climatic anomalies upon ocean-atmosphere interactions through its effects upon SAMS. (C) 2016 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 12/50260-6 - Structure and evolution of the Amazonian biota and its environment: an integrative approach
Grantee:Lúcia Garcez Lohmann
Support type: BIOTA-FAPESP Program - Thematic Grants