Topographic amplitude dependence of internal wave generation by tidal forcing over idealized three‐dimensional topography
Topographic amplitude dependence of internal wave generation by tidal forcing over idealized three‐dimensional topography
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DOI：
10.1029/2004jc002537
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发表时间：
2005-02
影响因子：
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通讯作者：
James R Munroe;K. Lamb
中科院分区：
文献类型：
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作者：
James R Munroe;K. Lamb
[1]这项使用普林斯顿海洋模型的数值研究研究了当振荡潮流流经理想化的三维高斯海山和绕过理想的三维高斯海山时，从东向传播的表面潮汐到内波场的能量转换。特别地，利用一定范围的水平纵横比研究了内波场中的能量通量与地形高度之间的关系。与理论一致的是，对于亚临界地形，能流随地形振幅ho的平方而增加。对于超临界地形，函数关系更加复杂，与纵横比有关。对于近临界地形，它比二氧化碳增加得更快。对于较大的圆形海山，能量通量的增加要慢得多，增加的速度随着幅度的增加而下降。随着海山沿跨潮波(南北)方向拉长，能量通量随高度增加得更快，对于二维海脊，能量通量增加约为ho2.2。能量通量的方向依赖性还取决于海山的纵横比和幅度。对于圆形海山，能量通量在与东西轴逆时针方向(北半球)20°到45°之间有最大值。对于拉长的海山，能量通量指向东西方向。
[1] This numerical study using the Princeton Ocean Model investigates the conversion of energy from an eastward propagating surface tide to the internal wave field as an oscillating tidal current flows over and around idealized three-dimensional Gaussian seamounts. In particular, the relationship between the energy flux in the internal wave field and the height of the topography is explored using a range of horizontal aspect ratios. In agreement with theory, the energy flux is found to increase as the square of the topographic amplitude ho for subcritical topography. For supercritical topographies the functional relationship is more complex aspect ratio dependent. It increases more rapidly than ho2 for near-critical topography. For larger circular seamounts the energy flux increases much more slowly, with the rate of increase dropping with amplitude. As the seamounts are elongated in the cross-tidal wave (north-south) direction the energy flux increases more rapidly with height and, for a two-dimensional ridge, increases as approximately ho2.2. The directional dependence of the energy flux also depends on the aspect ratio and amplitude of the seamount. For circular seamounts, energy flux has its maximum in directions between 20° and 45° counterclockwise from the east-west axis (Northern Hemisphere). For elongated seamounts the energy flux is directed in the east-west direction.