Sea Surface Temperature Variability in the Tropical Atlantic Since the Last Glacial Maximum

• Grant number: 25/11881-5
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: September 15, 2025
• End date: January 14, 2026
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Geological Oceanography
• Principal Investigator: Luigi Jovane
• Grantee: Lívia Flores Costa
• Supervisor: Rodrigo da Costa Portilho Ramos
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Bremen, Germany
• Associated to the scholarship: 23/12162-7 - Sedimentary Sources for the Brazilian Equatorial Margin between the Last Glacial Maximum and Recent, BP.IC

Abstract

The tropical Atlantic Ocean stands out due to its distinct patterns of oceanic and atmospheric circulation, including the influence of the South Equatorial Current (SEC) and the Intertropical Convergence Zone (ITCZ). Processes related to the circulation of the subtropical gyre and ocean-atmosphere interactions make this region particularly relevant for investigations involving inter-hemispheric exchanges with implications for climate change. In this context, the present study aims to investigate sea surface temperature (SST) variability from the Last Glacial Maximum (LGM) to the present, with a focus on cold events. SST is a key physical property whose spatial distribution results from various interactions within the ocean-atmosphere system and, in this region, was influenced by the hemispheric heat balance. The methods applied in this study focus on sediment core CG-GC-04 (00° 11.35'S; 29° 47.03'W), located near the São Pedro and São Paulo Archipelago in the central portion of the tropical Atlantic Ocean, situated between South America and Africa. The methodology is based on the analysis of magnesium (Mg) to calcium (Ca) elemental ratios in planktonic foraminifera, organisms known for their high sensitivity to environmental variations in seawater, capable of recording sea surface temperature in their calcareous shells. Therefore, the SST analyses obtained from these microfossils contribute to a deeper understanding of how the tropical Atlantic Ocean behaved during cold events over the last 20,000 years.