Quasi-Real-Time and High-Resolution Spatiotemporal Distribution of Ocean Anthropogenic CO2

• Published in: Geophysical Research Letters
• Main Authors: Li, B. F., Watanabe, Y. W., Hosoda, S., Sato, K., Nakano, Y.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union
• Subjects: 450; Pacific; Ocean acidification; Subarctic
• Online Access: http://hdl.handle.net/2115/76144; https://doi.org/10.1029/2018GL081639

Increasing marine uptake of anthropogenic CO2 (C-ant) causes global ocean acidification. To obtain a high-resolution spatiotemporal distribution of oceanic carbon chemistry, we developed new parameterizations of the seawater total alkalinity, and dissolved inorganic carbon from the ocean's surface to 2,000-m depth by using dissolved oxygen, water temperature (T), salinity (S), and pressure (P) data. Using the values of total alkalinity and dissolved inorganic carbon predicted by dissolved oxygen, T, S, and P data derived from autonomous biogeochemical Argo floats, we described the distribution of oceanic C-ant in the 2000s in the subarctic North Pacific at high spatiotemporal resolution. The C-ant was found about 300 m deeper than during the 1990s; its average inventory to 2,000 m was 24.8 +/- 10.2 mol/m(2), about 20% higher than the 1990s average. Future application of parameterizations to global biogeochemical Argo floats data should allow the detailed global mapping of spatiotemporal distributions of CO2 parameters. Plain Language Summary:Age Cy Ocean absorbs the increasing atmospheric CO2 by human activities from 1750s and encourages global ocean acidification. To obtain the human-activity-derived CO2 in the subarctic North Pacific in a high resolution, we applied our empirical ocean carbon chemistry equations using other hydrographic parameters to autonomous biogeochemical Argo floats data. The amount of human-activity-derived CO2 in this region was found about 300 m deeper than during the 1990s and about 20% higher than the 1990s average. Our method allows the development of a system for monitoring long-term trend changes in ocean carbon chemistry similar to other time series stations.