Evaluation of the mechanisms acting on the Atlantic Meridional Overturning Circulation in CESM2 for the 1pctCO2 experiment


  • Lívia Sancho

    Laboratory of Computational Methods in Engineering, Civil Engineering Program, Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-617, Brazil

  • Elisa Passos

    Civil Engineering Program, Alberto Luiz Coimbra Institute for Graduate Studies and Engineering Research, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-617, Brazil

    Physical Oceanography Laboratory, Department of Physical Oceanography, Faculty of Oceanography, Rio de Janeiro State University, Rio de Janeiro, 20559-900, Brazil

  • Marcio Cataldi

    Climate System Monitoring and Modeling Laboratory, Water Resources and Environmental Engineering, Fluminense Federal University, 24020-140, Brazil

    Regional Atmospheric Modeling Group (MAR), Physics of the Earth, Department of Physics, Regional Campus of International Excellence (CEIR) “Campus Mare Nostrum”, University of Murcia, Murcia, 30100, Spain

  • Luiz Paulo de Freitas Assad

    Laboratory of Computational Methods in Engineering, Civil Engineering Program, Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-617, Brazil

    Department of Meteorology, Institute of Geosciences, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-617, Brazil

  • Luiz Landau

    Laboratory of Computational Methods in Engineering, Civil Engineering Program, Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-617, Brazil


Received: 6 November 2023 | Revised: 3 January 2024 | Accepted: 10 January 2024 | Published Online: 18 January 2024


The Atlantic Meridional Overturning Circulation (AMOC) is a crucial component of the Earth's climate system due to its fundamental role in heat distribution, carbon and oxygen transport, and the weather. Other climate components, such as the atmosphere and sea ice, influence the AMOC. Evaluating the physical mechanisms of those interactions is paramount to increasing knowledge about AMOC's functioning. In this study, the authors used outputs from the Community Earth System Model version 2 and observational data to investigate changes in the AMOC and the associated physical processes. Two DECK experiments were evaluated: piControl and 1pctCO2 , with an annual increase of 1% of atmospheric CO2 . The analysis revealed a significant decrease in the AMOC, 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. A vital aspect observed in this study is the association between increased runoff and reduced water evaporation, giving rise to a positive feedback process. Consequently, the rates of freshwater spreading have intensified during this period, which could lead to an accelerated disruption of the AMOC beyond the projections of existing models.


AMOC, Meridional cell, Climate change, Deep circulation, CESM2 results, CMIP6


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How to Cite

Sancho, L., Passos, E., Cataldi, M., Paulo de Freitas Assad, L., & Landau, L. (2024). Evaluation of the mechanisms acting on the Atlantic Meridional Overturning Circulation in CESM2 for the 1pctCO2 experiment. Journal of Atmospheric Science Research, 7(1), 40–58. https://doi.org/10.30564/jasr.v7i1.6070


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