Two Millennia of South Atlantic Convergence Zone Variability Reconstructed From Isotopic Proxies

Author(s):Show less -

Novello, V. F. ^[1] ; Cruz, F. W. ^[1] ; Moquet, J. S. ^[2] ; Vuille, M. ^[3] ; de Paula, M. S. ^[1] ; Nunes, D. ^[1] ; Edwards, R. L. ^[4] ; Cheng, H. ^{[4, 5]} ; Karmann, I. ^[1] ; Utida, G. ; Strikis, N. M. ^[6] ; Campos, J. L. P. S. ^[7]

Affiliation

^[1] Univ Sao Paulo, Inst Geociencias, Sao Paulo - Brazil

^[2] Inst Phys Globe Paris, Paris - France

^[3] SUNY Albany, Dept Atmospher & Environm Sci, Albany, NY 12222 - USA

^[4] Univ Minnesota, Dept Earth Sci, Minneapolis, MN - USA

^[5] Xi An Jiao Tong Univ, Inst Global Environm Change, Xian, Shaanxi - Peoples R China

^[6] Univ Fed Fluminense, Dept Geoquim, Niteroi, RJ - Brazil

^[7] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Sao Paulo - Brazil

• Document type: Journal article
• Source: Geophysical Research Letters; v. 45, n. 10, p. 5045-5051, MAY 28 2018.
• Web of Science Citations: 13

Abstract

Most reconstructions of the South American Monsoon System (SAMS) over the last two millennia are based on delta O-18 records from locations at high-elevation sites in the Andes, which are not influenced by the South Atlantic Convergence Zone (SACZ). Yet the SACZ is a key driver of SAMS variability over much of Brazil. Here we use two new delta O-18 records from speleothems sampled in the central and southwestern portions of the SACZ core to show that the SAMS was not varying in phase over the entire tropical continent during the last two millennia. In fact, speleothem records located to the northeast of the SACZ record precipitation variations that are antiphased with similar records on the opposite side of the SACZ, in particular during the Little Ice Age period, while records close to the core of the SACZ axis show no significant departure from the mean state during this period. (AU)

• FAPESP's process: 17/50085-3 - PIRE: climate research education in the Americas using tree-ring speleothem examples (PIRE-CREATE)
• Grantee: Francisco William da Cruz Junior
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/15807-5 - Paleoclimate and paleoenvironmental reconstructions over the last glacial period in the mid-west Brazil
• Grantee: Valdir Felipe Novello
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/10095-1 - South America monsoon system activity in certer-west of Brazil based in spelothem records associated with other paleoclimate records from South America
• Grantee: Valdir Felipe Novello
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 12/03942-4 - South America Monsoon System activity in certer-west of Brazil based in spelothem records associated with other paleoclimate records from South America
• Grantee: Valdir Felipe Novello
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 15/08351-2 - South America monsoon system activity in mid-west Brazil based in speleothems records associated with climate models
• Grantee: Valdir Felipe Novello
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 12/01187-4 - A calibration study in Central Brazil caves: implications for the paleoclimate inferences from speleothem records
• Grantee: Ivo Karmann
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/00299-4 - Geochemistry of vadose percolation in karst systems: implications for paleoclimatic interpretations os speleothem records
• Grantee: Ivo Karmann
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/23687-2 - Expansion of the paleoclimate records of speleothems collected in the mid-west of Brazil
• Grantee: Valdir Felipe Novello
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 12/50260-6 - Structure and evolution of the Amazonian biota and its environment: an integrative approach
• Grantee: Lúcia Garcez Lohmann
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 09/12902-3 - Variability of Summer Monsoon System over the Central-West Brazil during Holocene, based on paleoclimate records from speleothems.
• Grantee: Marcos Saito de Paula
• Support Opportunities: Scholarships in Brazil - Master