Precipitation stable isotopes revealing climatic connections between Central Amazon and Southeastern Brazil

• Grant number: 24/23661-7
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: April 21, 2025
• End date: October 20, 2025
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Didier Gastmans
• Grantee: Amanda Rodrigues Soares
• Supervisor: Shujiro Komiya
• Host Institution: Centro de Estudos Ambientais (CEA). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Institution abroad: Max-Planck-Institut Für Biogeochemie, Germany
• Associated to the scholarship: 24/06442-0 - Long Term Observation on Rain Stable Isotope in the Central Region of São Paulo State, BP.MS

Abstract

Assessments about time series over continuous observations on the variability of the isotopic composition of rainfall have been used to understand the effects of climate change, especially in temperate climate areas, but there is a gap in this type of analysis in tropical regions, especially due to the lack of continuity in these observations. Thus, studies in tropical regions are extremely important to assess the influence of meteorological parameters on the isotopic composition of rainfall, since these regions have a unique climate that has great influence on the distribution of rainfall regimes. The Amazon region has a wet equatorial climate with abundant rainfall and high temperatures, primarily influenced by the Intertropical Convergence Zone (ITCZ), which promotes significant convective activity. The moisture generated by the Amazon plays a crucial role in the rainfall regime of southeastern Brazil, especially during the rainy season, due to the South Atlantic Convergence Zone (SACZ). The transport of vapor along the atmospheric rivers intensifies rainfall in the Southeast by interacting with cold fronts moving into the region. Furthermore, isotopic studies carried out in the tropical Amazon forest, such as ATTO project, contribute to understanding the isotopic variability of rainfall in the region. Having established that vapor transported from the Amazon significantly contributes to the rainfall regime in southeastern Brazil, it is important to link isotopic information from the two regions. Based on this premise, the objective of this project is to compare the isotopic signatures of precipitation from Rio Claro and ATTO.