Thomas N. Lee  William E. Johns

Cho-Teng Liu

This research was funded by the National Science Foundation under Grant nos. OCE-9302187 and OCE-9818672. In a cooperative effort between the US and the Republic of China, moored observations of Kuroshio current structure and transport variability were made across the channel between northeast Taiwan and the Ryukyu Islands at 24 deg N between September 1994 and May 1996 (Fig. 1).

The mean structure of the downstream flow is shown in Fig. 2, together with instrument configuration. Mean flows reach speeds of 100 cm/s in a well-defined surface intensified axis located on the western side of the channel. The moored estimate of the Kuroshio mean transport is 21.7 Sverdrup with a standard deviation of 2 Sv. Transport variations ranged from a maximum of 39 to a minimum of 5 Sv.

Spectral analysis (Fig. 3) of the transport time series reveals that its variability is dominated by fluctuations on time scales of 3-4 months (~100 days), with secondary peaks at 35 and 15 days. These 100-day events are found to be associated with meandering of the current axis from the west to the east side of the channel.

Publications:

Lee, T.N., W. E. Johns, C.T. Liu, D. Zhang, R. Zantopp and Y. Yang, 2000: The Kuroshio east of Taiwan: Current structure and transport variability on daily to seasonal time scales. (submitted to J.  Phys. Oceanogr.)

Liu, C.T., S.P. Cheng, W.S. Chuang, Y. Yang, T.N. Lee, W.E. Johns and H.W. Li, 1998: Mean structure and transport of Taiwan Current (Kuroshio). Acta Oceanographica Taiwanica, 36, 159-176.

Johns, W.E., T.N. Lee, D. Zhang, R. Zantopp, C.T. Liu and Y. Yang, 2000: The Kuroshio east of Taiwan: Moored transport observations from the WOCE PCM-1 array. (submitted to J. Phys. Oceanogr.)

Yang, Y., C.T. Liu, T.N. Lee, W.E. Johns, H.W. Li and M. Koga, 2000: Sea surface slope as the estimator of the Kuroshio volume transport east of Taiwan. (submitted to J. Geophys. Res. Let.)

Zhang, D., W.E. Johns, T.N. Lee, C.T. Liu and R. Zantopp, 2000: The Kuroshio east of Taiwan: Modes of variability and relationship to interior mesoscale eddies. (submitted to J. Phys. Oceanogr.)

For further information, please contact:
Bill Johns (305) 361-4054 or Tom Lee (305) 361-4046