An Assessment of CO2 Uptake in the Arctic Ocean From 1985 to 2018 ...

• Main Authors: Yasunaka, Sayaka, Manizza, Manfredi, Terhaar, Jens, Olsen, Are, Yamaguchi, Ryohei, Landschützer, Peter, Watanabe, Eiji, Carroll, Dustin, Adiwira, Hanani, Müller, Jens Daniel, Hauck, Judith
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2023
• Subjects: 530 Physics; 550 Earth sciences & geology; Arctic; Arctic Ocean; Climate change; Sea ice
• Online Access: https://dx.doi.org/10.48350/193966; https://boris.unibe.ch/193966/

As a contribution to the Regional Carbon Cycle Assessment and Processes phase 2 (RECCAP2) project, we present synthesized estimates of Arctic Ocean sea-air CO2 fluxes and their uncertainties from surface ocean pCO2-observation products, ocean biogeochemical hindcast and data assimilation models, and atmospheric inversions. For the period of 1985–2018, the Arctic Ocean was a net sink of CO2 of 116 ± 4 TgC yr−1 in the pCO2 products, 92 ± 30 TgC yr−1 in the models, and 91 ± 21 TgC yr−1 in the atmospheric inversions. The CO2 uptake peaks in late summer and early autumn, and is low in winter when sea ice inhibits sea-air fluxes. The long-term mean CO2 uptake in the Arctic Ocean is primarily caused by steady-state fluxes of natural carbon (70% ± 15%), and enhanced by the atmospheric CO2 increase (19% ± 5%) and climate change (11% ± 18%). The annual mean CO2 uptake increased from 1985 to 2018 at a rate of 31 ± 13 TgC yr−1 dec−1 in the pCO2 products, 10 ± 4 TgC yr−1 dec−1 in the models, and 32 ± 16 TgC yr−1 dec−1 in ...