The application of neodymium isotopes to reconstruct AMOC variability and its role in the global carbon cycle during the last two glacial terminations

• Grant number: 22/01056-9
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: July 01, 2022
• End date: June 30, 2023
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Geological Oceanography
• Principal Investigator: Cristiano Mazur Chiessi
• Grantee: Bruna Borba Dias
• Supervisor: Alexander Piotrowski
• Host Institution: Escola de Artes, Ciências e Humanidades (EACH). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Cambridge, England
• Associated to the scholarship: 20/11452-3 - Carbon storage changes in the mid-depth South Atlantic during the penultimate glacial termination and the Anthropocene, BP.PD

Abstract

The Quaternary climate history of the Earth is marked by global-scale changes between glacial and interglacial conditions. However, glacial terminations are not similar to each other, and ocean circulation is considered to be one of the most important driving forces of terminations by its influence on atmospheric carbon dioxide levels. Changes in the Atlantic Meridional Overturning Circulation (AMOC) are considered to control the climate transition to interglacial conditions by its ability to transfer the carbon stored in the deep ocean to the atmosphere. However, AMOC variability is poorly constrained beyond the last glacial termination. Within this research internship we will reconstruct the intermediate and mid-depth ocean circulation based on neodymium isotope analyses in authigenic foraminiferal oxides from two western South Atlantic sediment cores that recorded AMOC dynamics during the last two glacial terminations. The to-be-obtained neodymium isotope results together with stable carbon isotope and grainsize data previously gathered within this Post-Doctorate project will allow us to trace the (i) propagation of North Atlantic Deep Water in the South Atlantic, (ii) changes in AMOC geometry, and (iii) its role in the global carbon cycle during the last two glacial terminations. (AU)