Late Quaternary Variations in the South American Monsoon System as Inferred by Speleothems-New Perspectives Using the SISAL Database

Autor(es)

Deininger, Michael ^[1] ; Ward, Brittany Marie ^[2] ; Novello, Valdir F. ^[3] ; Cruz, Francisco W. ^[3]

Afiliação do(s) autor(es)

^[1] Johannes Gutenberg Univ Mainz, Inst Geosci, JJ Becher Weg 21, D-55128 Mainz - Germany

^[2] Univ Waikato, Fac Sci & Engn, Private Bag 3105, Hamilton 3240 - New Zealand

^[3] Univ Sao Paulo, Inst Geosci, Rua Lago 562, BR-05508080 Sao Paulo - Brazil

• Tipo de documento: Artigo de Revisão
• Fonte: QUATERNARY; v. 2, n. 1 MAR 2019.
• Citações Web of Science: 6

Resumo

Here we present an overview of speleothem delta O-18 records from South America, most of which are available in the Speleothem Isotopes Synthesis and Analysis (SISAL\_v1) database. South American tropical and subtropical speleothem delta O-18 time series are primarily interpreted to reflect changes in precipitation amount, the amount effect, and consequently history of convection intensity variability of convergence zones such as the Intertropical Convergence Zone (ITCZ) and the South America Monsoon System (SAMS). We investigate past hydroclimate scenarios in South America related to the South American Monsoon System in three different time periods: Late Pleistocene, Holocene, and the last two millennia. Precession driven summertime insolation is the main driver of convective variability over the continent during the last 120 kyrs (from present day to 120 kyrs BP), including the Holocene. However, there is a dipole between speleothem delta O-18 records from western and eastern South America. Records located in the central region of Brazil are weakly affected by insolation-driven variability, and instead are more susceptible to the variability associated with the South Atlantic Convergence Zone (SACZ). Cold episodic events in the Northern Hemisphere, such as Heinrich and Bond Events, and the Little Ice Age, increase the convective activity of the SAMS, resulting in increased precipitation amount in South America. (AU)

• Processo FAPESP: 13/50297-0 - Dimensions US-BIOTA São Paulo: integrando disciplinas para a predição da biodiversidade da Floresta Atlântica no Brasil
• Beneficiário: Cristina Yumi Miyaki
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático
• Processo FAPESP: 18/12285-3 - Modelamento do sistema cárstico e sua relevância para a reconstituição paleoclimática do Brasil
• Beneficiário: Valdir Felipe Novello
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• Processo FAPESP: 17/50085-3 - PIRE: educação e pesquisa em clima das Américas usando os exemplos de anéis de árvores e espeleotemas (PIRE-CREATE)
• Beneficiário: Francisco William da Cruz Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 16/15807-5 - Reconstituição paleoclimática e paleoambiental do último período glacial no centro-oeste brasileiro
• Beneficiário: Valdir Felipe Novello
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado