The signature of the Mode Water in the Atmosphere of the South Atlantic

• Grant number: 25/11039-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Physical Oceanography
• Principal Investigator: Olga Tiemi Sato
• Grantee: Pâmela Batista dos Anjos
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This project investigates the influence of Subtropical Mode Water (STMW) formation in the South Atlantic on the atmosphere, focusing on ocean-atmosphere interactions during its formation period (July-October). STMW is characterized by vertical and horizontal homogeneity in temperature and salinity, occupying much of the subtropical basin (30°S-40°S). Its formation is driven by cooling and convective mixing in the upper ocean, modulated by interactions with the Brazil and Agulhas Currents, mesoscale eddies, and wind-induced Ekman transport.The central hypothesis is that cold advection, generated by surface winds prior to STMW formation, may alter local atmospheric patterns. The primary goal is to develop a methodology to identify this influence using: Satellite-derived sea surface temperature (SST), wind, sea level pressure, and water vapor data and in situ temperature/salinity profiles from Argo floats.Combined, these datasets will map upwelling regions linked to STMW and validate its relationship with atmospheric variables. The integrated analysis aims to establish a correlation pattern between STMW formation and changes in wind fields/other meteorological variables. Results will improve understanding of ocean-atmosphere coupling in the South Atlantic subtropical zone, with implications for climate and oceanic variability studies. (AU)