Carbon storage changes in the mid-depth South Atlantic during the penultimate glacial termination and the Anthropocene

• Grant number: 20/11452-3
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2020
• End date: April 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Geological Oceanography
• Principal Investigator: Cristiano Mazur Chiessi
• Grantee: Bruna Borba Dias
• Host Institution: Escola de Artes, Ciências e Humanidades (EACH). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 18/15123-4 - Past perspectives on tipping elements of the climate system: the Amazon Rainforest and the Atlantic Meridional Overturning Circulation (PPTEAM), AP.PFPMCG.JP2
• Associated scholarship(s): 22/01056-9 - The application of neodymium isotopes to reconstruct AMOC variability and its role in the global carbon cycle during the last two glacial terminations, BE.EP.PD

Abstract

Changes in the Atlantic Meridional Overturning Circulation (AMOC) are thought to play an important role in the carbon cycle by regulating atmospheric carbon dioxide (CO2) levels and the carbon storage in the deep ocean, particularly during glacial terminations. During the beginning of glacial terminations, the AMOC weakened substantially and the mid-depth Atlantic showed reduced ventilation, a process that favored carbon storage before the AMOC recovered to its interglacial mode. Although the efforts made to understand the AMOC control over mid-depth carbon storage, this process is still poorly constrained beyond the last glacial termination. New sedimentological records from past glacial terminations are necessary to elucidate the exact moment of deep circulation reactivation and carbon storage changes. Therefore, we propose to perform stable carbon and oxygen isotopic (13C and 18O) and radiogenic neodymium isotopic (Nd) analyses in foraminifera in order to (i) calibrate a circulation proxy based on preindustrial and Anthropocene samples, and (ii) to reconstruct the deep circulation in the Brazilian Margin during the penultimate glacial termination. This proposal will not only validate a proxy for deep circulation reconstruction, but also provide reconstructions with precise age control to define the timing of AMOC recovery, changes in carbon storage and atmospheric CO2 levels during the penultimate deglaciation.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SUAREZ-IBARRA, JAIME Y.; FREIRE, TIAGO M.; FROZZA, CRISTIANE F.; PINHO, TAINA M. L.; PETRO, SANDRO M.; DIAS, BRUNA B.; CHALK, THOMAS B.; CHAABANE, SONIA; SRIVASTAVA, MEDHAVI; COSTA, KAREN B.; et al. Surface fertilisation and organic matter delivery enhanced carbonate dissolution in the western South Atlantic. FRONTIERS IN ECOLOGY AND EVOLUTION, v. 11, p. 14-pg., 2023-11-03. (20/11452-3, 22/01056-9, 18/15123-4)

NASCIMENTO, R. A.; SANTOS, T. P.; VENANCIO, I. M.; CHIESSI, C. M.; BALLALAI, J. M.; KUHNERT, H.; GOVIN, A.; PORTILHO-RAMOS, R. C.; LESSA, D.; DIAS, B. B.; et al. Origin of delta C-13 minimum events in thermocline and intermediate waters of the western South Atlantic. QUATERNARY SCIENCE REVIEWS, v. 272, NOV 15 2021. (18/15123-4, 19/24349-9, 19/10642-6, 20/11452-3)

DIAS, BRUNA B.; PIOTROWSKI, ALEXANDER M.; BARBOSA, CATIA F.; VENANCIO, IGOR M.; CHIESSI, CRISTIANO M.; ALBUQUERQUE, ANA LUIZA S.. Coupled changes in western South Atlantic carbon sequestration and particle reactive element cycling during millennial-scale Holocene climate variability. SCIENTIFIC REPORTS, v. 11, n. 1, DEC 21 2021. (20/11452-3, 18/15123-4, 19/24349-9)