Abstract
Variations of current velocity of the Kuroshio are examined using the 1965–1983 sea-level difference between Naze and Nishinoomote, located on the offshore and onshore sides of the Kuroshio in the Tokara Strait south of Kyûshû.
Interannual variations of Kuroshio velocity are large, especially at periods longer than five years and around 2.1 years. They are almost determined by those of sea level on the offshore side of the Kuroshio. They are highly coherent with the offshore sea level at periods longer than 1.7 years, and incoherent with the onshore sea level at periods longer than 2.8 years.
The mean seasonal variation averaged for 19 years is at its maximum in July and at its minimum in the second half of October, with a sharp decrease in August and September. However, such a variation does not repeat every year. Amplitude, dominant period and phase are greatly different by year, and they can be roughly divided into four groups: small-amplitude group, semiannual-period group, and two annual-period groups with different phases. The only feature found in almost all years is a weak velocity from September to December.
The amplitude of seasonal variation tends to be large in the formation years of the large meander (LM) of the Kuroshio and small during the LM period. It is also large in the years preceding El Niño, and diminishes remarkably in El Niño years.
Kuroshio velocity in the Tokara Strait is incoherent with position of the Kuroshio axis over the Izu Ridge, but highly coherent with 70-day variations of coastal sea levels which are dominant during the LM period.
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Kawabe, M. (1980): Sea level variations around the Nansei Islands and the large meander in the Kuroshio south of central Japan. J. Oceanogr. Soc. Japan,36, 227–235.
Kawabe, M. (1985): Sea level variations at the Izu Islands and typical stable paths of the Kuroshio. J. Oceanogr. Soc. Japan,41, 307–326.
Kawabe, M. (1986): Transition processes between the three typical paths of the Kuroshio. J. Oceanogr. Soc. Japan,42, 174–191.
Kawabe, M. (1987): Spectral properties of sea level and time scales of Kuroshio path variations. J. Oceanogr. Soc. Japan,43, 111–123.
Konaga, S. and T. Inoue (1973): Relations between oceanographic conditions and the mean sea level in the adjacent sea of the Kii Peninsula. Umi to Sora,49, 45–49 (in Japanese with English abstract and legends).
Masuzawa, J. (1960): Statistical characteristics of the Kuroshio current. Oceanogr. Mag.,12, 7–15.
Masuzawa, J. (1961): Recent research on the Kuroshio current. Geogr. studies presented to Prof. Tsujimura in honor of his 70th birthday, 354–364 (in Japanese with English abstract).
Masuzawa, J. (1965): A note on the seasonal variation of the Kuroshio velocity. J. Oceanogr. Soc. Japan,21, 117–118 (in Japanese).
Minami, H., E. Kamihira, K. Komura, H. Eguchi and J. Nishizawa (1979): Statistical features of the oceanographic conditions south of Honshu, Japan. Part 2. In spring and autumn off Kii Peninsula. Bull. Kôbe Mar. Obs.,197, 1–11 (in Japanese with English abstract and legends).
Nitani, H. (1969): On the variability of the Kuroshio in recent several years. Bull. Japan. Soc. Fish. Oceanogr.,14, 13–18 (in Japanese).
Nitani, H. (1975): Variation of the Kuroshio south of Japan. J. Oceanogr. Soc. Japan,31, 154–173.
Nitani, H., S. Yoshida, J. Okumoto and H. Nakamura (1979): Statistics on the currents in the seas adjacent to Japan. Rep. Hydrogr. Res., No. 14, 57–91.
Schott, F. and R. Zantopp (1985): Florida Current: Seasonal and interannual variability. Science,227, 308–311.
Taft, B. (1972): Characteristics of the flow of the Kuroshio south of Japan. p. 165–216.In: Kuroshio—Its Physical Aspects, ed. by H. Stommel and K. Yoshida, Univ. Tokyo Press, Tokyo.
Takematsu, M., K. Kawatate, W. Koterayama, T. Suhara and H. Mitsuyasu (1986): Moored instrument observations in the Kuroshio south of Kyushu. J. Oceanogr. Soc. Japan,42, 201–211.
Uda, M. (1964): On the nature of the Kuroshio, its origin and meanders. p. 89–107.In: Studies on Oceanography, ed. by K. Yoshida, Univ. Tokyo Press, Tokyo.
Yosida, S. (1961): On the short period variation of the Kurosio in the adjacent sea of Izu Islands. Hydrogr. Bull., New Ser.,65, 1–18 (in Japanese with English abstract and legends).
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Kawabe, M. Variability of Kuroshio velocity assessed from the sea-level difference between Naze and Nishinoomote. Journal of the Oceanographical Society of Japan 44, 293–304 (1988). https://doi.org/10.1007/BF02302572
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DOI: https://doi.org/10.1007/BF02302572