Journal of Oceanography

, Volume 66, Issue 1, pp 71–83 | Cite as

East-west distribution of POC fluxes estimated from 234Th in the northern North Pacific in autumn

  • Hajime Kawakami
  • Makio C. Honda
  • Kazuhiko Matsumoto
  • Tetsuichi Fujiki
  • Shuichi Watanabe
Original Articles


Observations of primary productivity, 234Th, and particulate organic carbon (POC) were made from west to east across the northern North Pacific Ocean (from station K2 to Ocean Station Papa) during September–October 2005. Primary productivities in this region varied longitudinally from approximately 236 to 444 mgC m−2d−1 and clearly indicate the West High East Low (WHEL) trend. We estimated east-west variations in the POC flux from the surface layer (0–100 m) by using 234Th as a tracer. POC fluxes in the western region (44–53 mgC m−2d−1) were higher than those in the eastern region (21–34 mgC m−2d−1). However, the export ratios (e-ratios) ranged from approximately 8% to 16% and did not show the WHEL trend. Contrary to our expectation, no relation between POC flux (or e-ratio) and diatom biomass (or dominance) was apparent in autumn in the northern North Pacific.


Biological pump east-west northern North Pacific 234Th POC flux 


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Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Hajime Kawakami
    • 1
  • Makio C. Honda
    • 1
  • Kazuhiko Matsumoto
    • 1
  • Tetsuichi Fujiki
    • 1
  • Shuichi Watanabe
    • 1
  1. 1.Mutsu Institute for OceanographyJapan Agency for Marine-Earth Science and TechnologyAomoriJapan

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