The Arctic Ocean CO2 sink: Trends, uncertainties, and the impact of sea ice
Dutch, V.; Bakker, D.C.E.; Roobaert, A.; Landschützer, P.; Roden, N.P.; Hoppema, M.; Kaiser, J. (2025). The Arctic Ocean CO2 sink: Trends, uncertainties, and the impact of sea ice. Global Biogeochem. Cycles 39(8): 1-23. https://dx.doi.org/10.1029/2025gb008576
In: Global Biogeochemical Cycles. American Geophysical Union: Washington, DC. ISSN 0886-6236; e-ISSN 1944-9224
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| Author keywords |
Arctic Ocean; surface ocean pCO(2); ocean carbon sink; gas-exchange; global ocean; pco(2) climatology; carbon uptake; flux; variability; constant; nutrient; pacific; product |
| Auteurs | | Top |
- Dutch, V.
- Bakker, D.
- Roobaert, A.
- Landschützer, P.
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- Roden, N.P.
- Hoppema, M.
- Kaiser, J.
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| Abstract |
The Arctic Ocean covers 3 % of the Earth's surface but is estimated to contribute 5-14 % to the global ocean carbon sink. Sparse and unevenly distributed observations complicate our understanding of the size and the controlling mechanisms of this carbon sink. We adopt and advance the two-step neural network approach of Landsch & uuml;tzer et al. (2016, https://doi.org/10.1002/2015gb005359; Self Organizing Map-Feed Forward Network) to improve region-specific reconstructions of the surface ocean partial pressure of carbon dioxide (P(CO2 )) in the Arctic Ocean and subsequently estimate the air-sea CO2 flux. Our study shows that biogeochemical properties previously selected as predictor variables for P(CO2 ) at the global scale are not well suited to the Arctic Ocean and a sensitivity study reveals large differences in the size of the Arctic Ocean carbon sink depending on the choice of air-sea CO2 flux parameterization. This is most acute for those relating to sea ice cover, leading to a difference of up to 25 % (9.2-13.3 Pg C) in the total size of the Arctic Ocean carbon sink over the 32-year duration of the study. |
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