Variability of the Transports by the Deep Waters in the South Atlantic

• Grant number: 24/09961-8
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2024
• End date: October 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Physical Oceanography
• Principal Investigator: Edmo José Dias Campos
• Grantee: Edmo José Dias Campos
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Alberto Piola ; César Barbedo Rocha ; Maria Paz Chidichimo ; Mathias Campos van Caspel ; Olga Tiemi Sato ; Paulo Simionatto Polito ; Renellys C. Perez ; Shenfu Dong
• Associated scholarship(s): 25/05519-1 - Freshwater Transport across the SAMBA Line: Variability, Drivers, and Implications, BP.MS; 25/03785-6 - Use of machine learning techniques to study the variability of the meridional volume, heat and salt transport at SAMBA line (34.5S), BP.IC

Abstract

Recent studies show that it is becoming more likely the occurrence of abrupt climate changes still in the present century. One of these studies, based on the freshwater budget in the Atlantic Ocean, suggests an early warning signal, capable of foreseeing 25 years earlier abrupt changes in climate. In that study, results of numerical experiments with climate models and reanalysis products show that the collapse of the ocean currents that help to regulate climate could be occurring at such speed that adaptation would not be possible. However, given the insufficient information from current reanalyses, only sustained observations could provide a more reliable estimate of the distance to a tipping point. That article concludes that observations at 34oS are of utmost importance and will become crucial to estimate how close we are from a collapse. Coincidentally, since 2008 a large international program has been conducted for observations in the South Atlantic, with outstanding leadership and participation of Brazil. This program includes a series of observational platforms installed along 34.5oS and in the Vema Channel, a narrow passage in the bottom topography connecting the Argentine to the Brazil Basin. In this project, it is proposed a detailed investigation of the mean conditions and variability of the deep waters in the region, and of the transports of heat and freshwater by the ocean circulation in the South Atlantic. It will emphasize the study of temporal variation of the freshwater transport by the meridional overturning circulation at 34.5oS, the indicator of possible climate instabilities. Observational data, available or being collected in the South Atlantic will be analyzed. Additionally, numerical simulations and machine learning models will be used to estimate the meridional transports of heat and freshwater. (AU)