Tidal current fluctuations in the Soya Current

Abstract

Long-term current measurements were carried out near the Soya Strait in the Okhotsk Sea during a period from February 1980 to September 1982. The data were divided into five segments, each being 150 days long, and the tidal ellipse parameters of major axis, minor axis, orientation, and phase for the four major constituents (M2, S2, K1 and O1 tides) were calculated at each segment. The major axis of the mean tidal ellipse averaged over five segments was 29.9 cm sec⁻¹ for O1 tide, 28.3 cm sec⁻¹ for K1 tide, 10.4 cm sec⁻¹ for M2 tide, and 3.7 cm sec⁻¹ for S2 tide. The phase and orientation of the tidal ellipse were much stable. But, the root mean square deviations of the major axis reached 20% of the mean values for all four constituents. The tidal currents estimated from the sea level records at Wakkanai and Esashi along the Hokkaido coast in the Okhotsk Sea show that their amplitudes and phases are in good agreement with the observed ones for all four constituents.