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ABSTRACT. This study evaluates how climate change might affect advective heat and volume transports in the South Atlantic Basin based on Intergovernmental Panel on Climate Change (IPCC) A1FI and B1 climate change scenarios projections. Using the Climatic Model 2.1 (CM2.1) results that were developed by the Geophysical Fluid Dynamics Laboratory (GFDL), integrated on the water column, analyses were conducted through two meridional sections and one zonal section of the study area (between 25 • S-70 • S and 70 • W-20 • E). The annual mean time series were analyzed using historical 100-year climate change scenarios. The analyses of the climate change experiment parameters were compared with those of the H2 climate scenario. The volume transport (VT) through the water column weakened of about 5% in average and the advective heat transport (HT) increased of about 22% at the Drake and Africa-Antarctic (AF-AA) passages at the end of the experiments. For the zonal section at 25 • S, direction oscillations were observed in the integrated VT through the water column due to velocity intensity variations of the water masses and a decrease of about 22% in the HT was observed. Thus, it was observed a decrease in the water and heat supplies at 25 • S due to the Drake and AF-AA VT behavior, which may alter deep circulation patterns.Keywords: water column analysis, advective heat transport, flow direction, Drake Passage, Africa-Antarctic passage. RESUMO. Baseado nas projeções dos cenários de mudanças climáticas A1FI e B1 do

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The Atlantic Meridional Overturning Circulation (AMOC) is a crucial component of the Earth’s climate system due to its fundamental role in the uptake and distribution of important tracers such as heat, carbon, and oxygen. Evaluating changes in AMOC in a warming climate is paramount to understanding the potential influence on global climate. In this study, we utilized outputs produced by the Community Earth System Model for Phase 6 of the Coupled Model Intercomparison Project, in addition to in situ data, to investigate changes in AMOC and the associated physical processes. Two experiments were carried out: a control experiment and an experiment with an annual increase of 1% CO2. Our analysis revealed a significant decrease in AMOC, with the upper branch weakening more than 60% and shallowing more than 600 m, compared to in situ data, leading to a reduction in heat transport to high latitudes in the North Atlantic. This decline was associated with changes in mixed layer depth and buoyancy in high latitudes of the North Atlantic, resulting in the shutdown of deep convection and potentially affecting the formation of North Atlantic Deep Water and Antarctic Bottom Water. Furthermore, the increase in CO2 levels altered the pattern of several parameters and the way they determine the flow of freshwater to the North Atlantic Ocean. Our findings suggest that continued warming may further weaken AMOC, with significant implications for global climate.