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Journal of Oceanography

, Volume 69, Issue 3, pp 285–293 | Cite as

Volume transports proceeding to the Kuroshio Extension region and recirculating in the Shikoku Basin

  • Akira NaganoEmail author
  • Kaoru Ichikawa
  • Hiroshi Ichikawa
  • Masanori Konda
  • Kiyoshi Murakami
Original Article

Abstract

The volume transport of the Kuroshio, the western boundary current of the North Pacific subtropical gyre, varies vigorously due to merging of disturbances propagating from the entire North Pacific. Taking into account the recirculation in the Shikoku Basin by the zonal observation line at 30°N to the west of the Izu–Ogasawara Ridge, we estimated the volume transport in the top 1,000 m layer toward the Kuroshio Extension region. The volume transport of the local recirculation gyre in the Shikoku Basin increases associated with the westward extension of the gyre, particularly in the period of the large meandering path of the Kuroshio south of Japan. Meanwhile, most of the transport variations toward the Kuroshio Extension region correspond to those of the Kuroshio transport on the continental slope south of Japan, which vary independently of those of the recirculation gyre.

Keywords

Kuroshio Kuroshio Extension Recirculation IES Satellite altimetry Volume transport 

Notes

Acknowledgments

The authors thank the members on board the R/V “Kaiyo” (cruise numbers KY04-12 and KY05-09) and “Tansei-maru” (KT04-13 and KT05-23) of JAMSTEC for collecting IES and hydrographic data. Also, the authors extend our sincere thanks to the members on board the R/V “Chofu-maru” and “Keifu-maru” of JMA and vessels of JMSDF for their efforts to collect the hydrographic data. Most of this study was done when K. Ichikawa belonged to JAMSTEC. The authors acknowledge Associate Prof. S. Fujio providing the corrected tidal records at Tosa-Shimizu. Thanks are extended to Editor-in-Chief (Prof. T. Hibiya) and anonymous reviewers for their helpful comments. This work was partly supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Grant-in-Aid for Scientific Research on Innovative Areas (22106007).

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Copyright information

© The Oceanographic Society of Japan and Springer Japan 2013

Authors and Affiliations

  • Akira Nagano
    • 1
    Email author
  • Kaoru Ichikawa
    • 2
  • Hiroshi Ichikawa
    • 1
  • Masanori Konda
    • 1
    • 3
  • Kiyoshi Murakami
    • 4
  1. 1.Research Institute for Global ChangeJapan Agency for Marine-Earth Science and TechnologyYokosukaJapan
  2. 2.Research Institute for Applied MechanicsKyushu UniversityFukuokaJapan
  3. 3.Graduate School of ScienceKyoto UniversityKyotoJapan
  4. 4.Global Environment Marine DepartmentJapan Meteorological AgencyTokyoJapan

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