An assessment of sea-air CO2 flux in the Arctic Ocean from 1985 to 2018
- 1Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
- 2Graduate School of Science, Tohoku University, Sendai, Japan
- 3Geosciences Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
- 4Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- 5Physics Institute, University of Bern, Switzerland
- 6Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
- 7University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway
- 8Flanders Marine Institute (VLIZ), Ostend, Belgium
- 9Max Planck Institute for Meteorology, Hamburg, Germany
- 10Moss Landing Marine Laboratories, San José State University, California, USA
- 11Environmental Physics, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Zürich, Switzerland
- 12Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
As a contribution to the Regional Carbon Cycle Assessment and Processes phase 2 (RECCAP2) project, we present synthesized estimates of the Arctic Ocean CO2 uptake and their uncertainties from state-of-the-art surface ocean pCO2-observation products, global and regional ocean biogeochemical models and atmospheric inversions. For the period of 1985−2018, the Arctic Ocean represents a net sink of CO2 of 103 ± 19 TgC yr−1 in the pCO2 products and 92 ± 30 TgC yr−1 in the ocean biogeochemical models. While the long-term mean CO2 uptake in the Arctic Ocean is primarily caused by steady-state fluxes of natural carbon, it is enhanced 28% by the atmospheric CO2 increase and 15% by climate change. Moreover, the climate effect in the Arctic Ocean has become more important in recent years. The CO2 uptake peaks in late summer and early autumn, and is low in winter because the sea ice cover inhibits sea-air fluxes. The annual mean of CO2 uptake increased due to the decreasing sea ice concentration both in the pCO2 products and the ocean biogeochemical models. Both, the mean CO2 uptake and the trend, is substantially weaker in the atmospheric inversions. Uncertainty across all estimates is large especially in the estimated surface ocean pCO2 values in the East Siberian Sea and the Laptev Sea, due to scarcity of observations and missing processes in models, such as land-sea fluxes and sediment dynamics.
How to cite: Yasunaka, S., Manizza, M., Terhaar, J., Olsen, A., Yamaguchi, R., Landschützer, P., Watanabe, E., Carroll, D., Adiwira, H., Müller, J., and Hauck, J.: An assessment of sea-air CO2 flux in the Arctic Ocean from 1985 to 2018, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-10462, https://doi.org/10.5194/egusphere-egu23-10462, 2023.
