Variations in Antarctic Intermediate Water on the Brazilian south-southeast continental margin during the last 16 krys

• Grant number: 25/02658-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: August 01, 2025
• End date: February 29, 2028
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Geological Oceanography
• Principal Investigator: Silvia Helena de Mello e Sousa
• Grantee: Júlia Sambugaro Ribeiro
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 20/14356-5 - The Santos Bifurcation: present and past, AP.PFPMCG.TEM

Abstract

The circulation of the Atlantic Meridional Overturning Circulation (AMOC) is characterized in its upper branch by the Antarctic Intermediate Water (AAIW) and in its lower branch by the North Atlantic Deep Water (NADW), influencing water mass stratification and distribution, as well as the distribution of salt, heat, nutrients, and carbon in the oceans. The AMOC is essential in controlling Earth's climate by transporting heat to the Northern Hemisphere. The AMOC modulates climate change by controlling the heat and carbon absorption rate sequestered in the deep ocean. The project aims to understand the variability of the Intermediate Western Boundary Current (IWBC), which transports the AAIW and the AMOC from the last 16.000 years in the Southwest Atlantic. These reconstructions are important for a better understanding of the relationship between ocean circulation and climate, thereby improving the predictability of AMOC changes on longer timescales and increasing resolution in climate models. Sediment cores from the region will be used under the influence of the AAIW. Oceanographic proxies will be applied, such as sedimentological analyses, chemical elements in sediments and foraminiferal shells, stable oxygen and carbon isotopes in benthic foraminifera shells, and faunal analyses using benthic foraminifera. (AU)