Continental shelf waves off the Fukushima coast
Numerical experiments are performed on shelf waves forced by wind stress with a spectral peak around a period of 100 hr. Water depth in the numerical model is a function of offshore distance only and resembles a bathymetric profile off the Fukushima coast. A pair of vortices alined in the offshore direction and a large vortex are reproduced and they propagate southward outside the forced region. Judging from the propagation speed, the former corresponds to the second-mode and the latter to the first-mode shelf waves. In the forced region, the propagation speed of a trough and a ridge is slow, 3–5km hr−1. These propagation characteristics reproduce those observed along the Fukushima coast and this propagation speed corresponds to that of second-and third-mode shelf waves. Thus, it is concluded that the periodical current fluctuations observed in the inshore region along the Fukushima coast are due to motions associated with the second-and third-mode shelf waves.
KeywordsVortex Numerical Model Water Depth Numerical Experiment Propagation Characteristic
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- Gill, A.E. and E. H. Schumann (1974): The generation of long shelf waves by the wind. J. Phys. Oceanogr.,4, 83–90.Google Scholar
- Kubota, M., K. Nakata and Y. Nakamura (1978): Characteristics of low-frequency current fluctuations off Fukushima. Kaiyo Kagaku (marine Science),10, 499–508. (in Japanese)Google Scholar
- Kubota, M., K. Nakata and Y. Nakamura (1981): Continental shelf waves off the Fukushima coast. Part 1. Observations. J. Oceanogr. Soc. Japan,37, 267–278.Google Scholar
- Kubota, M. (1982): Continental shelf waves off the Fukushima coast. Part 2. Theory of their generation. J. Oceanogr. Soc. Japan,38, 323–330.Google Scholar