Simultaneous estimation method of denitrification and nitrogen fixation in sea water

• Project/Area Number: 25550004
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Environmental dynamic analysis
• Research Institution: Hokkaido University
• Principal Investigator: WATANABE Yutaka 北海道大学, 地球環境科学研究科(研究院), 准教授 (90333640)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2014: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2013: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 海洋窒素循環 / 海水中脱窒 / 化学海洋学 / 窒素循環

Outline of Final Research Achievements

The aims of this study were to develop the high precise and simultaneous method for dissolved nitrogen and argon in the ocean, and to evaluate the oceanic amount of denitrification and nitrogen fixation by using the new approach. Using the above approaches, we found that the generation rate of dinitrification in the Sea of Okhotsk was over 7 micromole/kg/year despite no nitrogen fixation, and it significantly contributed to the oceanic nitrogen cycle in the North Pacific.

Research Products

• [Journal Article] Application of chemical tracers to estimate denitrification in the Okhotsk Sea (2014)
  • Author(s): Ito M., Y. W. Watanabe, M. Shigemitsu, S. S. Tanaka, J. Nishioka
  • Journal Title: Journal of Oceanography Volume: 70 Issue: 5 Pages: 415-424
  • DOI: 10.1007/s10872-014-0241-9
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Decadal shift of biogenic sinking particle flux in the western North Pacific subpolar region (2014)
  • Author(s): Watanabe, Y. W., M. Shigemitsu, T. Ujiie, H. Minami
  • Journal Title: Geophysical Research Letters Volume: 41 Issue: 2 Pages: 513-518
  • DOI: 10.1002/2013gl059142
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] 分析化学的アプローチによる海洋炭素窒素循環の時空間変動の把握 (2013)
  • Author(s): 渡辺豊
  • Journal Title: 分析化学 Volume: 62 Pages: 1049-1056
  • NAID: 130003382338
  • Peer Reviewed
• [Journal Article] Intensive mixing along an island chain controls oceanic biogeochemical cycles (2013)
  • Author(s): Nishioka, J., T. Nakatsuka, Y. W. Watanabe, I. Yasuda, K. Kuma, H. Ogawa, N. Ebuchi, A. Scherbinin, Y. N. Volkov, T. Shiraiwa and M. Wakatsuchi
  • Journal Title: GLOBAL BIOGEOCHEMICAL CYCLES Volume: 27 Issue: 3 Pages: 1-10
  • DOI: 10.1002/gbc.20088
  • NAID: 120005394546
  • Peer Reviewed
• [Presentation] 海洋における人間活動起源窒素の見積り (2013)
  • Author(s): 渡辺豊、重光雅仁
  • Organizer: 2013年度日本海洋学会秋季大会
  • Place of Presentation: 札幌、北海道大学
• [Presentation] オホーツク海における地球化学トレーサーを用いた脱窒の定量化に向けての試み (2013)
  • Author(s): 伊藤昌稚、渡辺豊、重光雅仁、田中伸一、西岡純
  • Organizer: 2013年度日本海洋学会秋季大会
  • Place of Presentation: 札幌、北海道大学
• [Book] Western Pacific Air-Sea Interaction Study (2014)
  • Author(s): Uematsu, M., Yokouchi, Y., Watanabe, Y. W., Takeda, S., Yamanaka, Y.
  • Publisher: TERAPUB