Extreme Rainfall Events in Southeastern South America (1970-2024): Analysis of Climatic Conditions, Atmospheric Teleconnection Patterns, and Trends

• Grant number: 24/16478-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: January 01, 2025
• End date: August 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Physical Geography
• Principal Investigator: Maria Elisa Siqueira Silva
• Grantee: Leonardo Rodrigues
• Host Institution: Faculdade de Filosofia, Letras e Ciências Humanas (FFLCH). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The precipitation regime of Southeastern South America (SEAS) is characterized by the influence of numerous atmospheric systems, with spatial and temporal variability influenced by climate modes. These modes contribute to the occurrence of extreme rainfall events in SEAS by intensifying atmospheric systems, as observed in the episode between April and May 2024 in Rio Grande do Sul. Future projections indicate an increased frequency of extreme events over SEAS. Extreme climate events in SEAS have the potential to impact major socio-economic activities, causing damage to physical infrastructure and resulting in fatalities. This research aims to analyze the climatic conditions associated with the occurrence of extreme rainfall events in Southeastern South America from 1970 to 2023 and compare them to 2024. Data will be sourced from CHIRPS, GPCC, and ERA5, as well as time series of climate indices such as ONI (ENSO), SAODI (SAD), and AMM (TAD). The properties of extreme events, weather conditions, and climate patterns will be analyzed, particularly those associated with teleconnections with the Pacific and Atlantic Oceans; historical episodes will be compared with the 2024 event; and climatic trends will be assessed. The analysis will be quantitative, based on the calculation of anomalies and trends. Computational resources will include the use of CDO, GrADS, R, and Python for operations. This research is expected to identify the climatic conditions associated with extreme rainfall events in Southeastern South America, contributing to decision-making, risk management, and planning.