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Summer insolation controlled movements of Intertropical Convergence Zone during last glacial cycle in northern South America

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Ramirez, V. M. ; Cruz, F. W. ; Vuille, M. ; Novello, V. F. ; Strikis, N. M. ; Cheng, H. ; Zhang, H. W. ; Bernal, J. P. ; Du, W. J. ; Ampuero, A. ; Deininger, M. ; Chiessi, C. M. ; Tejedor, E. ; Campos, J. L. ; Ait Brahim, Y. ; Edwards, R. L.
Número total de Autores: 16
Tipo de documento: Artigo Científico
Fonte: COMMUNICATIONS EARTH & ENVIRONMENT; v. 4, n. 1, p. 8-pg., 2023-12-21.
Resumo

A paradigm in paleoclimatology holds that shifts in the mean position of the Intertropical Convergence Zone were the dominant climatic mechanism controlling rainfall in the tropics during the last glacial period. We present a new paleo-rainfall reconstruction based on speleothem stable oxygen isotopes record from Colombia, which spans most of the last glacial cycle. The strength and positioning of the Intertropical Convergence Zone over northern South America were more strongly affected by summer insolation at high northern latitudes than by local insolation during the last glacial cycle, resulting in an antiphased relationship with climate in the Cariaco Basin. Our data also provide new insight into how orbital forcing amplified/dampened Intertropical Convergence Zone precipitation during millennial-scale events. During Greenland Stadial events, the Intertropical Convergence Zone was positioned close to the latitude of El Penon, as expressed by more negative delta 18O values. Greenland Interstadial events are marked by relatively high stable oxygen isotope values and reduced rainfall in the El Penon record, suggesting a northward withdrawal of the Intertropical Convergence Zone. During some Heinrich Stadial events, and especially Heinrich Stadial 1, the Intertropical Convergence Zone must have been displaced away from its modern location near El Penon, as conditions were very dry at both El Penon and Cariaco. The strength and positioning of the Intertropical Convergence Zone over northern South America were strongly related to Northern Hemisphere summer insolation during the last glacial cycle, according to speleothem oxygen isotope records from the Caracos Cave, central Colombia. (AU)

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: 22/08359-7 - Padrões inter-hemisférico de precipitação monçônica sob diferentes condições de temperatura nos últimos 140 KA e no Antropoceno
Beneficiário:Francisco William da Cruz Junior
Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular
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Beneficiário:Cristiano Mazur Chiessi
Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Regular
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
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)
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Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Jovens Pesquisadores - Fase 2