Climate-driven variability of the Southern Ocean CO2 sink ...

• Main Authors: Mayot, Nicolas, Le Quéré, Corinne, Rödenbeck, Christian, Bernardello, Raffaele, Bopp, Laurent, Djeutchouang, Laique M., Gehlen, Marion, Gregor, Luke, Gruber, Nicolas, Hauck, Judith, Iida, Yosuke, Ilyina, Tatiana, Keeling, Ralph F., Landschützer, Peter, Manning, Andrew C., Patara, Lavinia, Resplandy, Laure, Schwinger, Jörg, Séférian, Roland, Watson, Andrew J., Wright, Rebecca Mary, Zeng, Jiye
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2023
• Subjects: Southern ocean; Carbon sink; Climate; Oxygen; Interannual; Southern Ocean
• Online Access: https://dx.doi.org/10.3929/ethz-b-000612683; http://hdl.handle.net/20.500.11850/612683

The Southern Ocean is a major sink of atmospheric CO2, but the nature and magnitude of its variability remains uncertain and debated. Estimates based on observations suggest substantial variability that is not reproduced by process-based ocean models, with increasingly divergent estimates over the past decade. We examine potential constraints on the nature and magnitude of climate-driven variability of the Southern Ocean CO2 sink from observation-based air-sea O2 fluxes. On interannual time scales, the variability in the air-sea fluxes of CO2 and O2 estimated from observations is consistent across the two species and positively correlated with the variability simulated by ocean models. Our analysis suggests that variations in ocean ventilation related to the Southern Annular Mode are responsible for this interannual variability. On decadal time scales, the existence of significant variability in the air-sea CO2 flux estimated from observations also tends to be supported by observation-based estimates of O2 ... : Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 381 (2249) ...