Journal of Oceanography

, Volume 61, Issue 1, pp 129–139 | Cite as

Temporal Change of Dissolved Inorganic Carbon in the Subsurface Water at Station KNOT (44°N, 155°E) in the Western North Pacific Subpolar Region

  • Masahide Wakita
  • Shuichi Watanabe
  • Yutaka W. Watanabe
  • Tsuneo Ono
  • Nobuo Tsurushima
  • Shizuo Tsunogai
Article

Abstract

The dissolved inorganic carbon (DIC) and related chemical species have been measured from 1992 to 2001 at Station KNOT (44°N, 155°E) in the western North Pacific subpolar region. DIC (1.3∼2.3 µ mol/kg/yr) and apparent oxygen utilization (AOU, 0.7∼1.8 µmol/kg/yr) have increased while total alkalinity remained constant in the intermediate water (26.9∼27.3σθ). The increases of DIC in the upper intermediate water (26.9∼27.1σθ) were higher than those in the lower one (27.2∼ 27.3σθ). The temporal change of DIC would be controlled by the increase of anthropogenic CO2, the decomposition of organic matter and the non-anthropogenic CO2 absorbed at the region of intermediate water formation. We estimated the increase of anthropogenic CO2 to be only 0.5∼0.7 µmol/kg/yr under equilibrium with the atmospheric CO2 content. The effect of decomposition was estimated to be 0.8 ± 0.7 µmol/kg/yr from AOU increase. The remainder of non-anthropogenic CO2 had increased by 0.6 ± 1.1 µmol/kg/yr. We suggest that the non-anthropogenic CO2 increase is controlled by the accumulation of CO2 liberated back to atmosphere at the region of intermediate water formation due to the decrease of difference between DIC in the winter mixed layer and DIC under equilibrium with the atmospheric CO2 content, and the reduction of diapycnal vertical water exchange between mixed layer and pycnocline waters. In future, more accurate and longer time series data will be required to confirm our results.

Keywords

Dissolved inorganic carbon temporal change anthropogenic CO2 western North Pacific subpolar region 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Reference

  1. Anderson, L. A. and J. L. Sarmiento (1994): Redfield ratios of remineralization determined by nutrient data analysis. Global Biogeochem. Cycles, 8, 65–80.Google Scholar
  2. Bates, N. R. (2001): Interannual variability of oceanic CO2 and biogeochemical properties in the Western North Atlantic subtropical gyre. Deep-Sea Res., Parts II, 48, 1507–1528.Google Scholar
  3. Bates, N. R., A. C. Pequignet, R. J. Johnson and N. Gruber (2002): A short-term sink for atmospheric CO2 in subtropical mode water of the North Atlantic. Nature, 420, 489–493.PubMedGoogle Scholar
  4. Brewer, P. G. (1978): Direct observation of the oceanic CO2 increase. Geophys. Res. Lett., 5, 997–1000.Google Scholar
  5. Chen, C. T. A. and F. J. Millero (1979): Gradual increase of oceanic carbon dioxide. Nature, 227, 205–206.Google Scholar
  6. Culberson, C., R. M. Pytkowitcz and J. E. Hawley (1970): Seawater alkalinity determination by the pH method. J. Mar. Res., 28, 15–21.Google Scholar
  7. Dickson, A. G. and F. J. Millero (1987): A comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media. Deep-Sea Res., 40, 107–118.Google Scholar
  8. Dickson, A. G., G. C. Anderson and J. D. Afghan (2003): Reference materials for oceanic CO2 analysis: 1. Preparation, distribution and use. Mar. Chem. (submitted).Google Scholar
  9. DOE (1994): Handbook of Methods for the Analysis of the Various Parameters of the Carbon Dioxide in Sea Water; Ver. 2, ed. by A. G. Dickson and C. Goyet.Google Scholar
  10. Favorite, F., A. J. Dodimead and K. Nasu (1976): Oceanography of the subarctic Pacific region, 1960–1971. INPFC, 33, 1–187, Vancouver.Google Scholar
  11. Gloor, M., N. Gruber, J. Sarmiento, C. L. Sabine, R. A. Feely and C. Rodenbeck (2003): A first estimate of present and preindustrial air-sea CO2 flux patterns based on oceanic interior carbon measurements and models. Geophys. Res. Lett., 30, 1010, doi:10.1029/2002GL015594.Google Scholar
  12. Honda, M. C., K. Imai, Y. Nojiri, F. Hoshi, T. Sugawara and M. Kusakabe (2002): The biological pump in the northwestern North Pacific based on fluxes and major components of particulate matter obtained by sediment-trap experiments (1997–2000). Deep-Sea Res. II, 49, 5595–5625.CrossRefGoogle Scholar
  13. Imai, K., Y. Nojiri, N. Tsurushima and T. Saino (2002): Time series of seasonal variation of primary productivity at station KNOT (44°N, 155°E) in the sub-arctic western North Pacific. Deep-Sea Res. II, 49, 5395–5408.Google Scholar
  14. Isoda, Y., S. Shimizu, T. Izawa and T. Azumaya (2002): Interannual variations of North Pacific Intermediate Water across 155E and 180E sections in the subarctic North Pacific. Umi to Sora, 77, 143–151.Google Scholar
  15. Johnson, K., A. E. King and J. M. Sieburth (1985): Coulometric TCO2 analyses for marine studies: An introduction. Mar. Chem., 16, 61–81.Google Scholar
  16. Keeling, C. D. and T. P. Whorf (2002): Atmospheric CO2 records from sites in the SIO air sampling network. In Trends, A Compendium of Data on Global Change, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.Google Scholar
  17. Knap, A., A. Michaels, A. Close, H. Ducklow and A. Dickson (eds.) (1996): Protocols for the Joint Global Ocean Flux Study (JGOFS) core measurements. JGOFS Report No. 19, vi + 170 pp. Reprint of the IOC manuals and guides No. 29, UNESCO.Google Scholar
  18. Kono, T. (1997): Modification of the Oyashio Water in the Hokkaido and Tohoku areas. Deep-Sea Res. I, 44, 669–688.Google Scholar
  19. McNeil, B. I., R. J. Matear, R. M. Key, J. L. Bullister and J. L. Sarmiento (2003): Anthropogenic CO2 uptake by the ocean based on the global chlorofluorocarbon data set. Science, 299, 235–239.PubMedGoogle Scholar
  20. Mehrbach, C., C. H. Culberson, J. E. Hawley and R. M. Pytkowicz (1973): Measurement of the apparent dissociation constants of carbonic acid in the seawater at atmospheric pressure. Limnol. Oceanogr., 18, 897–907.Google Scholar
  21. Midorikawa, T., S. Sonoki, K. Saito, H. Takano, H. Kamiya, M. Ishii and H. I. Inoue (2003): Seasonal changes in oceanic pCO2 in the Oyashio region from winter to spring. J. Oceanogr., 59, 871–882.Google Scholar
  22. Millero, F. J. (1996): Chemical Oceanography. CRC Press, Boca Raton, Florida, 272 pp.Google Scholar
  23. Minobe, S. (1999): Resonance in bidecadal and pentadecadal climate oscillations over the North Pacific: role in climate regime shifts. Geophys. Res. Lett., 26, 855–858.Google Scholar
  24. Ono, T., S. Watanabe, K. Okuda and M. Fukasawa (1998): Distribution of total carbonate and related properties in the North Pacific along 30°N. J. Geophys. Res., 103, 30873–30883.Google Scholar
  25. Ono, T., Y. W. Watanabe and S. Watanabe (2000): Recent increase of DIC in the western North Pacific. Mar. Chem., 72, 317–328.Google Scholar
  26. Ono, T., T. Midorikawa, Y. W. Watanabe, K. Tadokoro and T. Saito (2001): Temporal increases of phosphate and apparent oxygen utilization in the subsurface waters of western subarctic Pacific from 1968 to 1998. Geophys. Res. Lett., 28, 3285–3288.Google Scholar
  27. Ono, T., K. Tadokoro, T. Midorikawa, J. Nishioka and T. Saino (2002): Multi-decadal decrease of net community production in western subarctic North Pacific. Geophys. Res. Lett., 29, 10.1029/2001GL014332.Google Scholar
  28. Redfield, A. C., B. H. Ketchum and F. A. Richards (1963): The influence of organisms on the composition of seawater. p. 26–77. In The Sea, ed. by M. H. Hill, Wiley-Interscience, New York.Google Scholar
  29. Reid, J. L. (1965): Intermediate waters of the Pacific Ocean. The John Hopkins Oceanographic Study, 2, Baltimore, p. 85.Google Scholar
  30. Slansky, C. M., R. A. Feely and R. H. Wanninkhof (1997): The stepwise linear regression method for calculating anthropogenic CO2 invasion into the North Pacific Ocean. Proceeding of International Marine Science Symposium on Biogeochemical Processes in the North Pacific, 70–79, Japan.Google Scholar
  31. Takahashi, Y., E. Matsumoto and Y. Watanabe (1999): Improved method for calculating anthropogenic CO2 in the upper layer of the North Pacific subtropical gyre along 175°E. J. Oceanogr., 55, 717–730.Google Scholar
  32. Talley, L. D. (1991): An Okhotsk Sea anomaly: implications for ventilation in the North Pacific. Deep-Sea Res. A, 38,Suppl., S171–S190.Google Scholar
  33. Tsunogai, S. (2000): North Pacific water’s larger potential sink capacity for absorbing anthropogenic CO2 and the processes recovering it. p. 533–560. In Dynamics and Characterization of Marine Organic Matter, ed. by N. Handa, E. Tanoue and T. Hama, TERRAPUB, Tokyo.Google Scholar
  34. Tsunogai, S., T. Ono and S. Watanabe (1993): Increase in the total carbonate in the western North Pacific water and a hypothesis on the missing sink of anthropogenic carbon. J. Oceanogr., 49, 305–315.Google Scholar
  35. Tsurushima, N., Y. Nogiri, K. Imai and S. Wanatabe (2002): Seasonal variations of carbon dioxide system and nutrients in the surface mixed layer at Station KNOT (44°N, 155°E) in the subarctic North Pacific. Deep-Sea Res. II, 49, 5377–5394.Google Scholar
  36. Ueno, H. and I. Yasuda (2000): Distribution and formation of the mesothermal structure (temperature inversions) in the North Pacific subarctic region. J. Geophys. Res., 105, 16885–16898.Google Scholar
  37. Watanabe, Y. W., Y. Takahashi, T. Kitao and K. Harada (1996): Total amount of oceanic excess CO2 taken from the North Pacific Subpolar Region. J. Oceanogr., 52, 301–312.Google Scholar
  38. Watanabe, Y. W., T. Ono and A. Shimamoto (2000): Increase in the uptake rate of oceanic anthropogenic carbon in the North Pacific determined by CFC ages. Mar. Chem., 72, 297–315.Google Scholar
  39. Wanatabe, Y. W., T. Ono, A. Shimamoto, T. Sugimoto, M. Wakita and S. Watanabe (2001): Probability of a reduction in the formation rate of the subsurface water in the North Pacific during the 1980s and 1990s. Geophys. Res. Lett., 28, 3289–3292.Google Scholar
  40. Wanatabe, Y. W., T. Ono, M. Wakita, N. Maeda and T. Gamo (2003): Synchronous bidecadal periodic changes of oxygen, phosphate and temperature between the Japan Sea deep water and the North Pacific intermediate water. Geophys. Res. Lett., 30, 10.1029/2003GL018338.Google Scholar
  41. Weiss, R. F. (1970): The solubility of nitrogen, oxygen and argon in water and seawater. Deep-Sea Res., 17, 721–735.Google Scholar
  42. Winn, C. D., Y. H. Lee, F. T. Mackenzie and D. M. Karl (1998): Rising surface ocean dissolved inorganic carbon at the Hawaii Ocean Time-series site. Mar. Chem., 60, 33–47.Google Scholar

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • Masahide Wakita
    • 1
    • 2
  • Shuichi Watanabe
    • 1
    • 2
  • Yutaka W. Watanabe
    • 1
  • Tsuneo Ono
    • 4
  • Nobuo Tsurushima
    • 3
  • Shizuo Tsunogai
    • 1
  1. 1.Graduate School of Environmental Earth ScienceHokkaido UniversitySapporoJapan
  2. 2.Japan Agency for Marine-Earth Science and TechnologyYokosukaJapan
  3. 3.National Institute for Advanced Industrial Science and TechnologyTsukubaJapan
  4. 4.Hokkaido National Fisheries Research InstituteKushiroJapan

Personalised recommendations