...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of oceanography >Instability of the Kuroshio in Luzon Strait: Effects of ridge topography and stratification
【24h】

Instability of the Kuroshio in Luzon Strait: Effects of ridge topography and stratification

机译：吕宋海峡黑潮的不稳定性：山脊地形和分层的影响

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The spectral analyses of moored current velocities in the central Luzon Strait reveal northward (i.e., downstream of the Kuroshio) propagation of a frontal wave with a five-day period, with wave amplitude increasing northward. Estimated from both curve fitting and frequency domain Empirical Orthogonal Function methods, the characteristics of five-day variations have wave speeds ranging from 32 to 40 cm s?1, wavelengths ranging from 130 to 150 km, and e-folding time scales for growth ranging from 0.8 to 3 days. An analytical two-layer model used to explore linear stability characteristics indicates that bottom topography (two meridional ridges) is important for the Kuroshio stability characteristics in the Luzon Strait. In the two-layer model with the two ridges, the flow is stabilized for the long-wave mode but destabilized for the short-wave mode (due to increasing vertical shear in the horizontal velocity). The analytical model produces wavelengths and phase speeds for the most unstable mode which is similar to the observation, but the growth rate is underestimated. However, a spectral numerical model applied with a more realistic stratification and velocity structure does obtain faster growth rates comparable to the observations. Parameter sensitivity tests were conducted using the analytical model. The characteristics of the most unstable mode are most sensitive to the surface front location relative to the bottom topography but not sensitive to varying the density difference and thickness of the upper layer.
机译：吕宋海峡中部系泊流速度的频谱分析显示，前波向北（即黑潮的下游）传播了五天的时间，波幅向北增大。根据曲线拟合和频域经验正交函数方法进行估算，五天变化的特征是波速范围从32到40 cm s？1，波长范围从130到150 km，以及电子折叠的时间尺度以适应增长从0.8到3天。用于探索线性稳定性特征的两层分析模型表明，底部地形（两个子午脊）对于吕宋海峡的黑潮稳定特征很重要。在具有两个脊的两层模型中，对于长波模式，流量是稳定的，但对于短波模式，流量是不稳定的（由于水平速度中垂直切变的增加）。该分析模型会为最不稳定的模式生成波长和相速度，这与观测值相似，但是增长率被低估了。然而，与更现实的分层和速度结构一起应用的光谱数值模型的确获得了与观测值相当的更快的生长速率。使用分析模型进行参数敏感性测试。相对于底部形貌，最不稳定模式的特征对表面前部位置最敏感，但对改变上层的密度差和厚度不敏感。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号