Copyright The Oceanographic Society of Japan. Change in pCO2 through Biological Activity in the Marginal Seas of the Western North Pacific: The Efficiency of the Biological Pump Estimated by a Sediment Trap Experiment

• Main Authors: Makio C. Honda, Masashi Kusakabe, Shigeto Nakabayashi, Steven J. Manganini, Susumu Honjo
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; Antarctic Ocean; Bering Sea; Okhotsk; Pacific; The Antarctic; Antarc*; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.551.2477; http://www.terrapub.co.jp/journals/JO/pdf/5306/53060645.pdf

We have carried out sediment trap experiments and observed seasonal variability in organic and inorganic carbon flux in the marginal seas of the western North Pacific (the Okinawa Trough, Ryukyu Trench, Bering Sea, and Sea of Okhotsk). Using empirical equations describing vertical changes in carbon flux and carbon equilibrium equations, the seasonal change or annual change in pCO2 of sea water in the upper water layer was estimated for each area. Results showed that biological activity (formation of settling particulate carbon) for each area decreased the pCO2 all year round. There was sig-nificant seasonal variability in the decrease in pCO2 in the Bering sea and the Sea of Okhotsk. Of the four areas, biological activity in the Bering Sea caused the greatest decrease in pCO2 (ca. 46 ± 13 ppm year–1). We also estimated the annual mean decrease in pCO2 owing to biological activity in the northwestern North Pacific, northeastern North Pacific, equatorial Pacific, North Atlantic, Arabian sea, and Antarctic oceans using time-series sediment trap experimental data. Our results show that the efficiency of the biological pump in decreasing pCO2 is higher in the Antarctic ocean and the northwestern North Pacific, including the Bering Sea, than in other areas. Keywords: ⋅Biological pump, ⋅ sediment trap experiment, ⋅Co/Ci ratio, ⋅vertical change in carbon flux, ⋅ carbonate equilib-rium, ⋅ δpCO2. 1.