Different precipitation patterns across tropical South America during Heinrich and Dansgaard-Oeschger stadials

Autor(es)

Zhang, Yancheng ^[1] ; Chiessi, Cristiano M. ^[2] ; Mulitza, Stefan ^[1] ; Sawakuchi, Andre O. ^[3] ; Haeggi, Christoph ^[1] ; Zabel, Matthias ^[1] ; Portilho-Ramos, Rodrigo C. ^[3] ; Schefuss, Enno ^[1] ; Crivellari, Stefano ^[3] ; Wefer, Gerold ^[1]

Afiliação do(s) autor(es)

^[1] Univ Bremen, MARUM Ctr Marine Environm Sci, Bremen - Germany

^[2] Univ Sao Paulo, Sch Arts Sci & Humanities, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Inst Geosci, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: QUATERNARY SCIENCE REVIEWS; v. 177, p. 1-9, DEC 1 2017.
• Citações Web of Science: 11

Resumo

Detailed knowledge about tropical South American precipitation patterns during Heinrich (H) and Dansgaard-Oeschger (DO) stadials provides relevant insights into the possible evolution of Amazonian hydroclimate under future climate change. Sediment core GeoB16224-1 (ca. 7 degrees N), raised from a site in the continental slope off French Guiana in western equatorial Atlantic under the influence of the Amazon River discharge, documents the impacts of H and DO stadials on both inorganic (i.e., Fe/Ca record) and organic (i.e., alkenone C-37 concentration and C-37/C-38 ratio) geochemistry between 41 and 13 ka BP. Our results show millennial-scale covariations of increased Fe/Ca values with decreased C37 concentration and C37/C38 ratios during H and DO stadials. Comparing our high temporal resolution data with previously published records from ca. 17 degrees N to 4 degrees S, we are able to differentiate the influence of H and DO stadials upon tropical South American precipitation. We find that records under the influence of the South American summer monsoon (e.g., western Amazon) and the northern edge of the Intertropical Convergence Zone (ITCZ) (e.g., northernmost South America) exhibit strong climate shifts during both H and DO stadials, but regions under the influence of the southern edge of the ITCZ (e.g., northeastern Brazil) experience a weaker reaction during DO stadials than during H stadials. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 12/50260-6 - Estruturação e evolução da biota amazônica e seu ambiente: uma abordagem integrativa
• Beneficiário: Lúcia Garcez Lohmann
• Linha de fomento: Auxílio à Pesquisa - Programa BIOTA - Temático
• Processo FAPESP: 11/06609-1 - Proveniência, transporte e estocagem de sedimentos nos rios amazônicos
• Beneficiário: André Oliveira Sawakuchi
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/17517-3 - Resposta da porção oeste do Oceano Atlântico às mudanças na circulação meridional do Atlântico: variabilidade milenar a sazonal
• Beneficiário: Cristiano Mazur Chiessi
• Linha de fomento: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Jovens Pesquisadores