Unusually high sea level at the south coast of Japan in September 2011 induced by the Kuroshio

• Norihisa Usui

• Koji Ogawa

• Kei Sakamoto

• Hiroyuki Tsujino

• Goro Yamanaka

• Tsurane Kuragano

• Masafumi Kamachi

Abstract

Using a coastal assimilation model, generation mechanism of unusually high sea level (UHSL) at the south coast of Japan in September 2011 is investigated. Both model results and tide gauge observations indicate that sea level rise associated with the UHSL event occurred twice in the middle and end of September. The first one, which is localized around the eastern part of the Seto Inland Sea, is caused by a cyclonic circulation in the Kii Channel formed as a result of northward migration of the Kuroshio axis toward Cape Shionomisaki. The second sea level rise, which is the main contributor to this UHSL event, is observed in wide areas not only at the south coast of Japan, but also at the coast of the Japan Sea. It is brought about by a coastal trapped wave (CTW) induced as a result of a fluctuation of the Kuroshio path to the south of the Boso Peninsula. The CTW with positive SSH anomalies propagates westward along the south coast of Japan, and then goes into the coast of the Japan Sea. Sensitivity experiments and a modal characteristic analysis indicate that the CTW is mainly characterized by the first mode baroclinic Kelvin wave. The phase speed for the first mode is calculated at 2.96 m s $$^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> , which compares well with that estimated by tide gauge observations.

Journal

• Journal of oceanography

  Journal of oceanography 77 (3), 447-461, 2021-06

  Tokyo : Oceanographic Society of Japan

Keywords

• Unusually high sea level
• Coastal sea level
• Coastal trapped wave
• Kuroshio path
• Coastal assimilation model

Details

• CRID: 1520010381244906496
• NII Article ID: 40022579304
• NII Book ID: AA10833529
• ISSN: 09168370
• ISSN: 1573868X
• DOI: 10.1007/s10872-020-00575-1
• NDL BIB ID: 031478328
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I031478328
• Web Site: https://link.springer.com/content/pdf/10.1007/s10872-020-00575-1.pdf
• Web Site: https://link.springer.com/article/10.1007/s10872-020-00575-1/fulltext.html
• Text Lang: en
• NDL Source Classification:
  • ZM44(科学技術--地球科学--海洋・陸水・火山)
• Data Source:
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN