Study on ocean circulation in the Pacific using noble gas tracers

2009 Fiscal Year Final Research Report

• Project/Area Number: 17101001
• Research Category: Grant-in-Aid for Scientific Research (S)
• Allocation Type: Single-year Grants
• Research Field: Environmental dynamic analysis
• Research Institution: The University of Tokyo
• Principal Investigator: SANO Yuji The University of Tokyo, 海洋研究所, 教授 (50162524)
• Co-Investigator(Kenkyū-buntansha): FUJIO Shinzou 東京大学, 海洋研究所, 准教授 (00242173) ; TAKAHATA Naoto 東京大学, 海洋研究所, 助教 (90345059) ; TANAKA Kiyoshi 東京大学, 海洋研究所, 助教 (20345060)
• Project Period (FY): 2005 – 2009
• Keywords: 海洋科学 / 地球化学 / 海洋物理 / 陸水学 / 地球観測 / 環境変動

Research Abstract

We have carried out high-quality observations of geochemical tracers such as helium isotopes as well as hydrographic data and direct current measurements to infer deep current routes in the Pacific. In the western North Pacific, there is a westward flow at 2500m deep going to the Philippine Sea while northward current along the Marina Arc is dominant at 3000m deep. At deeper than 4000m where helium isotope anomaly is not found, we have discovered a northward flow by direct current measurements. These observations are consistent with a result of high-resolution numerical simulation.

Research Products

• [Journal Article] Pacific Ocean circulation based on observation (2010)
  • Author(s): Kawabe, M., Fuiio, S.
  • Journal Title: Journal of Oceanography 66 Pages: 389-403
  • Peer Reviewed
• [Journal Article] Direct velocity measurements of deep circulation southwest ofthe Shatsky Rise in the western North Pacific (2010)
  • Author(s): Yanagimoto, D., Kawabe, M., Fujio, S.
  • Journal Title: Deep-Sea Research I 57 Pages: 328-337
  • Peer Reviewed
• [Journal Article] Helium isotopes of seawater in the Philippine Sea and the western North Pacific (2010)
  • Author(s): Takahata, N., Tokutake, T., Shirai, K., Fuiio, S., Tanaka, K., Sano, Y.
  • Journal Title: Geochemical Journal 44(掲載確定)
  • Peer Reviewed
• [Journal Article] Atmospheric helium isotope ratio : possible temporal and spatial variations (2010)
  • Author(s): Sano, Y., Furukawa, Y., Takahata, N.
  • Journal Title: Geochimicaet Cosmochimica Acta 74(掲載確定)
  • Peer Reviewed
• [Journal Article] Accurate measurement of atmospheric helium isotopes (2008)
  • Author(s): Sano, Y., Tokutake, T., Takahata, N.
  • Journal Title: Analytical Sciences 24 Pages: 521-525
  • Peer Reviewed
• [Journal Article] Helium isotopes of seawater in the Japan Sea (2008)
  • Author(s): Takahata, N., Sano, Y., Horiguchi, K., Shirai, K., Gamo, T.
  • Journal Title: Journal of Oceanography 64 Pages: 293-301
  • Peer Reviewed
• [Journal Article] Geochemical implications for the mechanism of deep convection in a semi-closed tropical marginal basin : Sulu Sea (2007)
  • Author(s): Gamo, T., Kato, Y., Hasumoto, H., Kakiuchi, H., Momoshima, N., Takahata, N., Sano, Y.
  • Journal Title: Deep Sea Research II 54 Pages: 4-13
  • Peer Reviewed
• [Journal Article] Effects of the Earth's rotation and bottom slope on density current descending a sloping bottom (2006)
  • Author(s): Tanaka, K.
  • Journal Title: Journal of Geophysical Research 111 Pages: C11018, doi : 10. 1029/2006JC003677
  • Peer Reviewed
• [Journal Article] ヘリウム同位体を用いた深層循環の研究 (2006)
  • Author(s): 高畑直人, 清田馨, 佐野有司
  • Journal Title: 月刊海洋 38 Pages: 370-375
• [Journal Article] 日本近海のヘリウム同位体比 (2005)
  • Author(s): 佐野有司, 高畑直人, 清田馨
  • Journal Title: 月刊海洋 号外39 Pages: 45-52
• [Journal Article] Measurements of noble gas solubility in seawater by a quadrupole mass spectrometer (2005)
  • Author(s): Sano, Y., Takahata, N.
  • Journal Title: Journal of Oceanography 61 Pages: 465-473
  • Peer Reviewed
• [Journal Article] Helium-3 plume over the East Pacific Rise at 25°S (2005)
  • Author(s): Takahata, N., Agarwal, M., Nishizawa, M., Shirai, K., Inoue, Y., Sano, Y.
  • Journal Title: Geophysical Research Letter 32 Pages: L11608
  • Peer Reviewed
• [Journal Article] Benthic Front and the Yamato Basin Bottom Water in the Japan Sea (2005)
  • Author(s): Senjyu T., Y. Isoda, T. Aramaki, S. Otosaka, S. Fujio, D. Yanagimoto, T. Suzuki, K. Kuma, K. Mori
  • Journal Title: Journal of Oceanoeraphy 61 Pages: 1047-1058
  • Peer Reviewed
• [Presentation] 海洋深層へのヘリウム-3人為散布による海洋深層流評価の試み (2009)
  • Author(s): 亀田綾乃, 高畑直人, 北島宏輝, 藤尾伸三, 田中潔, 佐野有司
  • Organizer: 日本地球化学会年会
  • Place of Presentation: 広島, 日本
  • Year and Date: 2009-09-06
• [Presentation] Distribution of helium-3 plume and deep-sea circulation in the northwestern Pacific Ocean (2009)
  • Author(s): Sano, Y., Tokutake, T., Takahata, N., Shirai, K., Fujio, S., Tanaka, K.
  • Organizer: Goldschmidt Conference
  • Place of Presentation: Davos, Switzerland
  • Year and Date: 2009-06-23
• [Presentation] Accurate measurement of atmospheric helium isotopes (2009)
  • Author(s): Sano, Y., Furukawa, Y., Takahata, N.
  • Organizer: Noble gas workshop (Dingue2009)
  • Place of Presentation: Nancy, France
  • Year and Date: 2009-06-20
• [Presentation] CTDとLADCPによる鉛直拡散係数の推定 (2009)
  • Author(s): 藤尾伸三, 川辺正樹
  • Organizer: 日本海洋学会春季大会
  • Place of Presentation: 東京, 日本
  • Year and Date: 2009-04-08
• [Presentation] 日本海溝周辺における深層流の時間変動 (2008)
  • Author(s): 藤尾伸三, 柳本大吾, 北川庄司
  • Organizer: 日本海洋学会秋季大会
  • Place of Presentation: 呉, 日本
  • Year and Date: 2008-09-27
• [Presentation] Precise measurement of atmospheric helium isotopes (2008)
  • Author(s): Sano, Y., Tokutake, T., Furukawa Y., Takahata N.
  • Organizer: European Geosciences Union General Assembly
  • Place of Presentation: Vienna, Austria
  • Year and Date: 2008-04-18
• [Presentation] High 3^He emanation observed in a forearc region of the Kinki distrct (2007)
  • Author(s): Sano, Y., Takahata, N., Yamamoto, J.
  • Organizer: SW Japan : Revisited. International Conference on Gas Geochemistry
  • Place of Presentation: Taipei, Taiwan
  • Year and Date: 2007-10-01
• [Presentation] Distribution of helium-3 plumes and deep-sea circulation in the central Pacific Ocean (2007)
  • Author(s): Takahata, N., Kiyota, K., Shirai, K., Nishizawa, M., Sano, Y., Gamo, T.
  • Organizer: Goldschmidt Conference
  • Place of Presentation: Cologne, Germany
  • Year and Date: 2007-08-21
• [Presentation] 南太平洋におけるヘリウム同位体比の分布と深層循環 (2007)
  • Author(s): 高畑直人, 清田馨, 白井厚太朗, 西澤学, 佐野有司, 蒲生俊敬
  • Organizer: 日本海洋学会春季大会
  • Place of Presentation: 東京, 日本
  • Year and Date: 2007-03-23
• [Presentation] Helium isotopes of seawater in adjacent sea of Japan (2006)
  • Author(s): Sano, Y., Horiguchi, K., Takahata, N., Shirai, K.,Oda, S., Gamo, T.
  • Organizer: Goldschmidt Conference
  • Place of Presentation: Melbourne, Australia
  • Year and Date: 2006-08-29
• [Remarks]
  • URL: http://cer.aori.u-tokyo.ac.jp/kibanS/