Changes in surface hydrography at the western tropical Atlantic during the Younger Dryas

Autor(es):Mostrar menos -

Venancio, I. M. ^[1] ; Shimizu, M. H. ^[1] ; Santos, T. P. ^[2] ; Lessa, D. O. ^[2] ; Portilho-Ramos, R. C. ^[3] ; Chiessi, C. M. ^[4] ; Crivellari, S. ^[5] ; Mulitza, S. ^[3] ; Kuhnert, H. ^[3] ; Tiedemann, R. ^[6] ; Vahlenkamp, M. ^[3] ; Bickert, T. ^[3] ; Sampaio, G. ^[1] ; Albuquerque, A. L. S. ^[2] ; Veiga, S. ^[1] ; Nobre, P. ^[1] ; Nobre, C. ^[7]

Afiliação do(s) autor(es)

^[1] Natl Inst Space Res INPE, Ctr Weather Forecasting & Climate Studies CPTEC, Cachoeira Paulista - Brazil

^[2] Univ Fed Fluminense, Programa Geociencias Geoquim, Niteroi, RJ - Brazil

^[3] Univ Bremen, MARUM Ctr Marine Environm Sci, Bremen - Germany

^[4] Univ Sao Paulo, Sch Arts Sci & Humanities, Sao Paulo - Brazil

^[5] Univ Sao Paulo, Inst Geosci, Sao Paulo - Brazil

^[6] Alfred Wegener Inst Polar & Marine Res, Bremerhaven - Germany

^[7] Univ Sao Paulo, Inst Adv Studies, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: GLOBAL AND PLANETARY CHANGE; v. 184, JAN 2020.
• Citações Web of Science: 0

Resumo

During the Younger Dryas (YD), paleoceanographic proxies indicate a weakening of the Atlantic Meridional Overturning Circulation (AMOC) resulting in a widespread surface cooling of the North Atlantic and a southward displacement of the Intertropical Convergence Zone (ITCZ). In the western tropical Atlantic, competing ocean and atmospheric processes may result in contrasting surface hydrography scenarios north and south of the equator during the YD. Based on new and compiled data, we provide an up-to-date model-data comparison of changes in western tropical Atlantic surface hydrography during the YD. We show that both transient model simulations and proxy results indicate warming of sea surface temperatures (SST) in the western tropical South Atlantic, but disagree for the SST in the western tropical North Atlantic. Proxies also reveal a complex spatial pattern in surface salinity in the western tropical Atlantic, while a broad negative anomaly is observed in the model output. By comparing planktonic foraminiferal Ba/Ca records from different records in the western tropical Atlantic we constrain ITCZ shifts from the YD to the early Holocene. Based on the Ba/Ca records, the ITCZ reached its southernmost position between 13 and 11.8 ka and started to move northward reaching its northernmost position between 10.8 and 9.7 ka. (AU)

• Processo FAPESP: 18/15123-4 - Perspectivas pretéritas sobre limiares críticos do sistema climático: a Floresta Amazônica e a célula de revolvimento meridional do Atlântico (PPTEAM)
• Beneficiário: Cristiano Mazur Chiessi
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Jovens Pesquisadores - Fase 2