Shut down of the South American summer monsoon during the penultimate glacial

Author(s):Show less -

Rodriguez-Zorro, Paula A. ^[1] ; Ledru, Marie-Pierre ^{[1, 2]} ; Bard, Edouard ^[3] ; Aquino-Alfonso, Olga ^{[1, 2]} ; Camejo, Adriana ^[4] ; Daniau, Anne-Laure ^[5] ; Favier, Charly ^{[1, 2]} ; Garcia, Marta ^[3] ; Mineli, Thays D. ^{[6, 1]} ; Rostek, Frauke ^[3] ; Ricardi-Branco, Fresia ^[4] ; Sawakuchi, Andre Oliveira ^[6] ; Simon, Quentin ^[3] ; Tachikawa, Kazuyo ^[3] ; Thouveny, Nicolas ^[3]

Affiliation

^[1] Univ Montpellier, ISEM, CNRS, EPHE, IRD, F-34095 Montpellier - France

^[2] Sawakuchi, Andre Oliveira, Univ Sao Paulo, Inst Geosci, Sao Paulo, Brazil.Rodriguez-Zorro, Paula A., Univ Montpellier, ISEM, CNRS, EPHE, IRD, F-34095 Montpellier - France

^[3] Aix Marseille Univ, CEREGE, CNRS, IRD, INRAE, Coll France, F-13545 Aix En Provence - France

^[4] Univ Estadual Campinas, Inst Geosci, BR-13081970 Campinas - Brazil

^[5] Univ Bordeaux, UMR 5805, CNRS, EPOC, F-33615 Pessac - France

^[6] Univ Sao Paulo, Inst Geosci, Sao Paulo - Brazil

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 10, n. 1 APR 15 2020.
• Web of Science Citations: 2

Abstract

We analysed changes in mean annual air temperature (MAAT), vegetation and biomass burning on a long and continuous lake-peat sediment record from the Colonia basin, southeastern Brazil, examining the responses of a wet tropical rainforest over the last 180 ka. Stronger southern atmospheric circulation up to the latitude of Colonia was found for the penultimate glacial with lower temperatures than during the last glacial, while strengthening of the South American summer monsoon (SASM) circulation started during the last interglacial and progressively enhanced a longer wet summer season from 95 ka until the present. Past MAAT variations and fire history were possibly modulated by eccentricity, although with signatures which differ in average and in amplitude between the last 180 ka. Vegetation responses were driven by the interplay between the SASM and southern circulation linked to Antarctic ice volume, inferred by the presence of a cool mixed evergreen forest from 180 to 45 ka progressively replaced by a rainforest. We report cooler temperatures during the marine isotope stage 3 (MIS 3: 57-29 ka) than during the Last Glacial Maximum (LGM: 23-19 ka). Our findings show that tropical forest dynamics display different patterns than mid-latitude during the last 180 ka. (AU)

• FAPESP's process: 13/50297-0 - Dimensions US-BIOTA São Paulo: a multidisciplinary framework for biodiversity prediction in the Brazilian Atlantic forest hotspot
• Grantee: Cristina Yumi Miyaki
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants