Age model determination, stable oxygen isotope record, and XRF ln(Ti/Ca) and ln(Fe/K) of piston core M125-95-3

DOI

Continental and marine paleoclimate archives from northwestern and northeastern South America recorded positive precipitation anomalies during Heinrich Stadials (HS). These anomalies have been classically attributed to enhanced austral summer (monsoon) precipitation. However, the lack of marine paleoclimate records off eastern South America as well as inconsistencies between southeastern South American continental and marine records hamper a comprehensive understanding of the mechanism responsible for (sub-) tropical South American hydroclimate response to HS. Here we investigate piston core M125-95-3 collected off eastern South America (10.94°S) and simulate South American HS conditions with a high-resolution version of an atmosphere-ocean general circulation model. Further, meridional changes in precipitation over (sub-) tropical South America were assessed with a thorough compilation of previously available marine paleorecords. Our ln(Ti/Ca) and ln(Fe/K) data show increases during HS6-Younger Dryas. It is the first core off eastern South America and the southernmost from the Atlantic continental margin of South America that unequivocally records HS-related positive precipitation anomalies. Based on our new data, model results and the compilation of available marine records, we propose a new mechanism for the positive precipitation anomalies over tropical South America during HS. The new mechanism involves austral summer precipitation increases only over eastern South America while the rest of tropical South America experienced precipitation increases during the winter, challenging the widely held assumption of a strengthened monsoon. South American precipitation changes were triggered by dynamic and thermodynamic processes including a stronger moisture supply from the equatorial North Atlantic (tropical South Atlantic) in austral winter (summer).

Supplement to: de Carvalho Campos, Marília; Chiessi, Cristiano Mazur; Prange, Matthias; Mulitza, Stefan; Kuhnert, Henning; Paul, André; Venancio, Igor Martins; Albuquerque, Ana Luiza Spadano; da Cruz Junior, Francisco William; Bahr, André (2019): A new mechanism for millennial scale positive precipitation anomalies over tropical South America. Quaternary Science Reviews, 225, 105990

Identifier
DOI https://doi.org/10.1594/PANGAEA.905181
Related Identifier IsSupplementTo https://doi.org/10.1016/j.quascirev.2019.105990
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.905181
Provenance
Creator de Carvalho Campos, Marília ORCID logo; Chiessi, Cristiano Mazur ORCID logo; Prange, Matthias (ORCID: 0000-0001-5874-756X); Mulitza, Stefan ORCID logo; Kuhnert, Henning ORCID logo; Paul, André (ORCID: 0000-0003-1961-139X); Venancio, Igor Martins ORCID logo; Albuquerque, Ana Luiza Spadano ORCID logo; da Cruz Junior, Francisco William; Bahr, André
Publisher PANGAEA
Publication Year 2019
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 3 datasets
Discipline Earth System Research
Spatial Coverage (-36.206 LON, -10.945 LAT)