Storms drive outgassing of CO2 in the subpolar Southern Ocean
Nicholson, S.-A.; Whitt, D.B.; Fer, I.; du Plessis, M.D.; Lebéhot, A.D.; Swart, S.; Sutton, A.J.; Monteiro, P.M.S. (2022). Storms drive outgassing of CO2 in the subpolar Southern Ocean. Nature Comm. 13(1): 158. https://dx.doi.org/10.1038/s41467-021-27780-w
In: Nature Communications. Nature Publishing Group: London. ISSN 2041-1723; e-ISSN 2041-1723, more
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| Authors | | Top |
- Nicholson, S.-A.
- Whitt, D.B.
- Fer, I.
- du Plessis, M.D.
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- Lebéhot, A.D.
- Swart, S.
- Sutton, A.J.
- Monteiro, P.M.S.
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| Abstract |
The subpolar Southern Ocean is a critical region where CO2 outgassing influences the global mean air-sea CO2 flux (FCO2). However, the processes controlling the outgassing remain elusive. We show, using a multi-glider dataset combining FCO2 and ocean turbulence, that the air-sea gradient of CO2 (∆pCO2) is modulated by synoptic storm-driven ocean variability (20 µatm, 1–10 days) through two processes. Ekman transport explains 60% of the variability, and entrainment drives strong episodic CO2 outgassing events of 2–4 mol m−2 yr−1. Extrapolation across the subpolar Southern Ocean using a process model shows how ocean fronts spatially modulate synoptic variability in ∆pCO2 (6 µatm2 average) and how spatial variations in stratification influence synoptic entrainment of deeper carbon into the mixed layer (3.5 mol m−2 yr−1 average). These results not only constrain aliased-driven uncertainties in FCO2 but also the effects of synoptic variability on slower seasonal or longer ocean physics-carbon dynamics. |
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