The Southern Ocean plays a key role in atmospheric CO2 sequestration, accounting for ~40-50% of the anthropogenic CO2 absorbed by the modern ocean. The size of this sink is attributed to strong watermass sinking (i.e., mode/intermediate water and bottom water formation), which transports carbon to the mid- and deep-ocean thus isolating it from the atmosphere for centuries. The Southern Ocean also played a critical role in atmospheric pCO2 variations in the geologic past on both orbital and millennial timescales. Moreover, the Southern Ocean modulates atmospheric and oceanic circulation in the tropics remotely, influencing low-latitude atmospheric CO2 exchange. Thus, the Southern Ocean is a key component of the global climate system, whose operation must be better understood at a range of timescales in order to accurately assess its effects on atmospheric pCO2 in the future. This Research Topic will consist of a set of cutting-edge investigations of the processes and mechanisms of Southern Ocean influence on atmospheric pCO2 and global climate change.Integration of modern observations, paleoclimate data, and model simulations at a range of timescales will promote a comprehensive understanding of the significance of the Southern Ocean in global climate change from the perspective of carbon cycle. Spatio-temporal resolution of modern observations on carbon and other physical, chemical, and biological parameters are still the main constraint on a full understanding of key processes controlling carbon sequestration in the Southern Ocean. An insufficiency of key initial data and boundary conditions impedes a full understanding of carbon uptake and storage processes, accurate prediction of future carbon sink potential, and quantification of climate forcings and feedbacks inferred from paleorecords. The relative importance of factors such as surface productivity versus deep convection of the Southern Ocean in the evolution of atmospheric pCO2 at a range of timescales still needs further investigation. Therefore, integrated studies based on modern observations, paleoclimate records, and model simulations can lay a foundation for a better understanding of the role of the Southern Ocean in atmospheric CO2 exchange, both in the past as well as in the future. The purpose of this Research Topic is to explore the processes and mechanisms of the influence of the Southern Ocean on atmospheric pCO2 variations and its role in global climate change. We encourage submission to this Research Topic of innovative studies of carbon-related modern observations, model simulations and palaeoceanographic/paleoclimatic reconstructions of the Southern Ocean. We are particularly interested in in-depth studies integrating observations, simulations and paleorecords. We welcome original research, perspective, and review papers focused on, but not limited to, the following themes: • Analyses based on in-situ observations of carbon and other nutrients (e.g., N, P, and Si) and watermass factors (e.g., temperature, salinity, and density)• Simulations of the Southern Ocean as a carbon sink • Model-record comparisons to resolve past carbon cycle forcing in the Southern Ocean• Palaeoceanographic and paleoclimatic reconstructions of carbon cycle processes and their controls
The Southern Ocean plays a key role in atmospheric CO2 sequestration, accounting for ~40-50% of the anthropogenic CO2 absorbed by the modern ocean. The size of this sink is attributed to strong watermass sinking (i.e., mode/intermediate water and bottom water formation), which transports carbon to the mid- and deep-ocean thus isolating it from the atmosphere for centuries. The Southern Ocean also played a critical role in atmospheric pCO2 variations in the geologic past on both orbital and millennial timescales. Moreover, the Southern Ocean modulates atmospheric and oceanic circulation in the tropics remotely, influencing low-latitude atmospheric CO2 exchange. Thus, the Southern Ocean is a key component of the global climate system, whose operation must be better understood at a range of timescales in order to accurately assess its effects on atmospheric pCO2 in the future. This Research Topic will consist of a set of cutting-edge investigations of the processes and mechanisms of Southern Ocean influence on atmospheric pCO2 and global climate change.Integration of modern observations, paleoclimate data, and model simulations at a range of timescales will promote a comprehensive understanding of the significance of the Southern Ocean in global climate change from the perspective of carbon cycle. Spatio-temporal resolution of modern observations on carbon and other physical, chemical, and biological parameters are still the main constraint on a full understanding of key processes controlling carbon sequestration in the Southern Ocean. An insufficiency of key initial data and boundary conditions impedes a full understanding of carbon uptake and storage processes, accurate prediction of future carbon sink potential, and quantification of climate forcings and feedbacks inferred from paleorecords. The relative importance of factors such as surface productivity versus deep convection of the Southern Ocean in the evolution of atmospheric pCO2 at a range of timescales still needs further investigation. Therefore, integrated studies based on modern observations, paleoclimate records, and model simulations can lay a foundation for a better understanding of the role of the Southern Ocean in atmospheric CO2 exchange, both in the past as well as in the future. The purpose of this Research Topic is to explore the processes and mechanisms of the influence of the Southern Ocean on atmospheric pCO2 variations and its role in global climate change. We encourage submission to this Research Topic of innovative studies of carbon-related modern observations, model simulations and palaeoceanographic/paleoclimatic reconstructions of the Southern Ocean. We are particularly interested in in-depth studies integrating observations, simulations and paleorecords. We welcome original research, perspective, and review papers focused on, but not limited to, the following themes: • Analyses based on in-situ observations of carbon and other nutrients (e.g., N, P, and Si) and watermass factors (e.g., temperature, salinity, and density)• Simulations of the Southern Ocean as a carbon sink • Model-record comparisons to resolve past carbon cycle forcing in the Southern Ocean• Palaeoceanographic and paleoclimatic reconstructions of carbon cycle processes and their controls