Bispectral Analysis of Energy Transfer within the Two-Dimensional Oceanic Internal Wave Field
Bispectral Analysis of Energy Transfer within the Two-Dimensional Oceanic Internal Wave Field
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DOI：
10.1175/jpo2816.1
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发表时间：
2005-11
影响因子：
3.5
通讯作者：
N. Furuichi;T. Hibiya;Y. Niwa
中科院分区：
文献类型：
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作者：
N. Furuichi;T. Hibiya;Y. Niwa
摘要 对二维海洋内波场对低模半日内潮发生的数值再现光谱响应进行了双谱分析。在赤道30°纬度附近，低模半日内潮主要与两个高垂直波数日间（近惯性）内波相互作用，形成参数次谐波不稳定（PSI）类型的共振三重奏。由于这种相互作用提高了高垂直波数近惯性能级，因此增强了小水平和垂直尺度的能量级联。因此，双谱分析表明，低模半日内潮中的能量并不是直接转移到小尺度，而是通过高垂直波数近惯性流切变的发展。相比之下，在双谱线极地~30°以及赤道~25°处没有发现明显的能量级联到高垂直波数。一项新发现是，尽管 PSI 可能...
Abstract Bispectral analysis of the numerically reproduced spectral responses of the two-dimensional oceanic internal wave field to the incidence of the low-mode semidiurnal internal tide is performed. At latitudes just equatorward of 30°, the low-mode semidiurnal internal tide dominantly interacts with two high-vertical-wavenumber diurnal (near inertial) internal waves, forming resonant triads of parametric subharmonic instability (PSI) type. As the high-vertical-wavenumber near-inertial energy level is raised by this interaction, the energy cascade to small horizontal and vertical scales is enhanced. Bispectral analysis thus indicates that energy in the low-mode semidiurnal internal tide is not directly transferred to small scales but via the development of high-vertical-wavenumber near-inertial current shear. In contrast, no noticeable energy cascade to high vertical wavenumbers is recognized in the bispectra poleward of ∼30° as well as equatorward of ∼25°. A new finding is that, although PSI is possib...