Study of mechanism for sea level variability along the Japanese coast on the timescales from 10 days to a decade using data assimilation

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400472
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Japan, Meteorological Research Institute
• Principal Investigator: Usui Norihisa 気象庁気象研究所, 海洋・地球化学研究部, 主任研究官 (50370333)
• Co-Investigator(Renkei-kenkyūsha): HIROSE Nariaki 気象庁気象研究所, 海洋地球化学研究部, 研究官 (20748074)
• Research Collaborator: YASUDA Tamaki 気象庁, 地球環境海洋部・情報課, エルニーニョ情報管理官 ; FUKUDA Yoshikazu 気象庁, 地球環境海洋部, 海洋気象課調査官 ; MOTOYAMA Tatsuya 気象庁, 地球環境海洋部, 海洋気象情報室技術専門官
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 沿岸水位 / 沿岸捕捉波 / 異常潮位 / 黒潮続流 / 十年規模変動 / 貯熱量 / 対馬暖流 / データ同化

Outline of Final Research Achievements

Four-dimensional variational ocean reanalysis for the western North Pacific (FORA-WNP30) was produced to study sea level variability along the Japanese coast on the timescales from 10 days to a decade. It is the first-ever dataset covering the western North Pacific over 3 decades at eddy-resolving resolution. FORA-WNP30 clarified a generation mechanism of an unusual tide that occurred in 2001. It was caused by a coastal-trapped waves (CTWs) induced as a result of a short-term fluctuation of the Kuroshio path. The CTWs play an important role not only in the unusual tide on 2011 but also in the long-term variability of the Japanese coastal sea level, which synchronizes with the decadal variability of the Kuroshio extension. It is also shown that the long-term coastal sea-level variability has a significant impact on long-term variability of ocean heat content in the Japan Sea by changing volume transport at the Tsushima Strait.

Free Research Field

海洋物理学