Temperature and salinity distribution across the Kuroshio in the Shikoku basin

Autor: SEKINE, Yoshihiko
Jazyk: angličtina
Rok vydání: 2002
Předmět:
Zdroj: 三重大学生物資源学部紀要 = The bulletin of the Faculty of Bioresources, Mie University. 29:63-74
ISSN: 0915-0471
Popis: 四国海盆内部の黒潮を横断する水温と塩分分布の7回の観測を,1992年7月から2001年8月までに三重大学生物資源学部の練習船『勢水丸』を用いて行った。観測はとりわけ西岸境界流としての黒潮強流帯の水温構造と塩分極小層内部の塩分分布に注目した。この論文では観測された黒潮を横断する水温と塩分分布を提示した。観測結果の解析により,黒潮の強流帯の下で塩分極小層が不明確で,伊豆海嶺の西側でも塩分極小層は黒潮の陸側と沖側に分離することが示された。また,陸側と沖側の塩分極小層を成す海水がそれぞれ親潮中層水と北太平洋中層水であることが示された。黒潮の関連する水温躍層の傾きと反対方向の水温躍層の傾きが南の沖側で観測され,黒潮の沖側に西向きの反流を伴う高気圧循環が存在することが示され,日本南岸の黒潮は非線形効果の卓越した西岸境界流であることが示唆された。
Temperature and salinity observations across the Kuroshio in the Shikoku Basin have been made seven times during the period from July 1992 to August 2001 by use of the training vessel Seisui-maru of Mie University. Focus is placed on the temperature structure in the strong Kuroshio flow as a western bounndary current and the salinity distribution in the salinity minimum layer with the North Pacific Intermediate Water. All the observed temperature and salinity distribution across the Kuroshio mean flow is presented in this paper. It is shown that the salinity minimum layer is unclear under the mean flow of the Kuroshio and the less saline water is separated towords the coastal and offshore sides of the Kuroshio main axis in the western region of the Izu Ridge. It is also shown that sources of the salinity minimum water in the coastal and the offshore sides are Intermediate Oyashio Water and North Pacific Intermediate Water, respectively. Opposite temperature gradients associated with the mean flow of the Kuroshio are commonly observed to the south of the mean Kuroshio flow, which implies the existence of counter currents forming anti-cyclonic circulation in the offshore region. It is geophysically indicated that the formation of the anti-cyclonic circulations is associated with the high nonlinearity of the Kuroshio south of Japan.
Databáze: OpenAIRE
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