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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Equatorial Pacific forcing of western Amazonian precipitation during Heinrich Stadial 1

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Autor(es):
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Zhang, Yancheng ; Zhang, Xu ; Chiessi, Cristiano M. ; Mulitza, Stefan ; Zhang, Xiao ; Lohmann, Gerrit ; Prange, Matthias ; Behling, Hermann ; Zabel, Matthias ; Govin, Aline ; Sawakuchi, Andr O. ; Cruz, Francisco W. ; Wefer, Gerold
Número total de Autores: 13
Tipo de documento: Artigo Científico
Fonte: SCIENTIFIC REPORTS; v. 6, OCT 25 2016.
Citações Web of Science: 1
Resumo

Abundant hydroclimatic evidence from western Amazonia and the adjacent Andes documents wet conditions during Heinrich Stadial 1 (HS1, 18-15 ka), a cold period in the high latitudes of the North Atlantic. This precipitation anomaly was attributed to a strengthening of the South American summer monsoon due to a change in the Atlantic interhemispheric sea surface temperature (SST) gradient. However, the physical viability of this mechanism has never been rigorously tested. We address this issue by combining a thorough compilation of tropical South American paleorecords and a set of atmosphere model sensitivity experiments. Our results show that the Atlantic SST variations alone, although leading to dry conditions in northern South America and wet conditions in northeastern Brazil, cannot produce increased precipitation over western Amazonia and the adjacent Andes during HS1. Instead, an eastern equatorial Pacific SST increase (i.e., 0.5-1.5 degrees C), in response to the slowdown of the Atlantic Meridional Overturning Circulation during HS1, is crucial to generate the wet conditions in these regions. The mechanism works via anomalous low sea level pressure over the eastern equatorial Pacific, which promotes a regional easterly low-level wind anomaly and moisture recycling from central Amazonia towards the Andes. (AU)

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