High-resolution reconstruction of South American precipitation variations over the last two millennia

• Grant number: 24/19287-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2025
• End date: June 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal Investigator: Vinícius Ribau Mendes
• Grantee: João Lucas Ferrari
• Host Institution: Instituto do Mar (IMar). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated research grant: 22/02957-0 - Effects of the South Atlantic warming over South American precipitation, AP.PNGP.PI

Abstract

Rainfall patterns directly or indirectly affect all forms of life on the continent, from biomes with little human interference to densely populated areas. Precipitation influences both fauna and flora, impacting water availability, land use and occupation, hydroelectric power generation, and agricultural production. In Brazil, only about 10% of agricultural production is artificially irrigated, making it heavily dependent on the annual rainfall regime. Despite its reliance on rain, agriculture accounts for approximately 35% of the national GDP (Gross Domestic Product, CEPEA-USP, 2021). Furthermore, around 60% of Brazil's energy matrix is based on hydroelectric generation (EPE, 2020). Therefore, changes in rainfall patterns can cause social disruption and significant economic losses. To better project possible future precipitation change scenarios, it is necessary to validate climate models using sample data. Thus, we propose in this project to reconstruct the precipitation variations over the last two millennia for the main Brazilian river basins. To achieve this goal, a quartz luminescence-based precipitation indicator will be applied to five marine sediment cores. (AU)