2000年7月
The generation of large-amplitude unsteady lee waves by subinertial K-1 tidal flow: A possible vertical mixing mechanism in the Kuril Straits
JOURNAL OF PHYSICAL OCEANOGRAPHY
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- 巻
- 30
- 号
- 7
- 開始ページ
- 1601
- 終了ページ
- 1621
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1175/1520-0485(2000)030<1601:TGOLAU>2.0.CO;2
- 出版者・発行元
- AMER METEOROLOGICAL SOC
Numerical experiments with a two-dimensional nonhydrostatic model are performed to investigate tidally generated internal waves in the Kuril Straits and their effect on vertical mixing. The results show that sill-scale internal waves at the K-1, tidal frequency are confined to the sill slopes because the K-1, tide is subinertial in the Kuril Straits. In contrast to previous theories, the authors show that intense short internal waves generated at the sill breaks by the subinertial K-1, tidal current can propagate upstream as the tidal current slackens. Theoretical considerations identify these short waves as unsteady lee waves, which tend to be trapped at the generation region and:row into large-amplitude waves, eventually inducing vigorous mixing along their ray paths. In particular, superposition of a propagating unsteady lee wave and a newly generated lee wave over a sill causes significant wave breaking lending to a maximum vertical diffusivity of similar to 10(3) cm(2) s(-1). This quite intense mixing reaches down to the density layer of the North Pacific Intermediate Water (NPIW). In contrast, the M-2, tidal current does not cause such strong vertical mixing, because most of generated internal waves propagate away as first-mode internal tides and because the barotropic flow amplitude is small. The authors therefore suggest the possibility that generation of lee waves through interactions between the K-1, current and the bottom topography of the Kuril Straits contributes to the observed modification of the Okhotsk Sea water required in the formation of the NPIW.
- リンク情報
- ID情報
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- DOI : 10.1175/1520-0485(2000)030<1601:TGOLAU>2.0.CO;2
- ISSN : 0022-3670
- CiNii Articles ID : 10024686401
- Web of Science ID : WOS:000088583700006