Late Holocene Climate Variability on Opposite Margins of South America: Are There Teleconnections?

• Grant number: 25/18821-8
• Support Opportunities: FAPESP Program for the South Atlantic and Antarctica (PROASA) - Regular Program Grants
• Start date: February 01, 2026
• End date: January 31, 2029
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Geological Oceanography
• Principal Investigator: Michel Michaelovitch de Mahiques
• Grantee: Michel Michaelovitch de Mahiques
• Principal researcher abroad: Praxedes Muñoz
• Institution abroad: Universidad Católica del Norte , Chile
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• City of the host institution: São Paulo
• Associated researchers: Antonio Maldonado Castro ; Carolina Elizabeth Merino Guzman ; Giovanna Orletti Del Rey ; Ilana Elazari Klein Coaracy Wainer ; Ivan Felipe Benavides Martinez ; José Garcés-Vargas ; Márcia Caruso Bícego ; Renata Hanae Nagai ; Rubens Cesar Lopes Figueira ; Silvia Helena de Mello e Sousa

Abstract

This project aims to investigate climate and environmental variability during the Late Holocene (~last 3,000 years) along the opposite continental margins of South America: the southeastern Brazilian shelf (South Atlantic) and the Chilean continental margin and subtropical Andes (South Pacific). The main objective is to assess whether climatic changes occurred synchronously across these regions and to identify the role of large-scale ocean-atmosphere teleconnections linking the Pacific and Atlantic basins. We will analyze a suite of well-preserved sediment cores through a standardized multiproxy approach, combining organic, inorganic, isotopic, and biological indicators to reconstruct past sea surface temperature, hydroclimate, productivity, and redox variability. Chronologies will be established with 14C and 210Pb dating. Statistical and time-series approaches will identify dominant modes of variability, while cross-site comparisons will test the synchronicity of major events such as the Medieval Climate Anomaly and the Little Ice Age. Proxy reconstructions will be integrated with paleoclimate model ensembles (PMIP, CMIP) to clarify the influence of large-scale modes, including El Niño-Southern Oscillation, Southern Annular Mode, Pacific Decadal Oscillation, and South Atlantic modes. Artificial Intelligence methods will be applied to detect non-linear proxy-climate relationships and to develop new climate indices better tailored to South American hydroclimate. Expected outcomes include new high-resolution climate records, a direct assessment of synchronicity between Atlantic and Pacific climate systems, and refined frameworks for understanding teleconnections. By fostering collaboration between Brazilian and Chilean institutions, the project will strengthen knowledge of past South American climate dynamics and improve perspectives for anticipating future climate scenarios. (AU)