The Interaction of Equatorial Kelvin Waves with Realistically Sheared Zonal Currents
The Interaction of Equatorial Kelvin Waves with Realistically Sheared Zonal Currents
复制标题
赤道开尔文波与实际剪切纬向流的相互作用
DOI：
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发表时间：
1986
期刊：
影响因子：
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通讯作者：
L. Rothstein
中科院分区：
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作者：
M. Mcphaden;J. A. Proehl;L. Rothstein
摘要本文在一个线性化的连续层结模式中研究了斜压赤道Kelvin波与真实剪切背景纬向流的相互作用。背景气流处于热成风平衡状态，并允许在纬向和垂直方向上连续变化。长波扰动的控制方程在时间和经度上都是调和的，它被简化为一个二阶压力偏微分方程，然后用有限差分形式进行数值求解。我们的研究结果表明，背景射流的存在下，可以显着修改的斜压开尔文波的结构和色散特性，这取决于速度和空间尺度的射流相对于那些波。最低的斜压模式，它有一个纬向相速度远大于典型的平均流量，是最少的结构修改和多普勒频移。高斜压模态的多普勒频移更为明显，并经历强的扰动。
Abstract We investigate the interaction of baroclinic equatorial Kelvin waves with realistically sheared background zonal currents in a linearized, continuously stratified model. The background flows are in thermal wind balance and allowed to vary continuously in the meridional and vertical directions. The governing equations for long-wave perturbations that are harmonic in time and longitude are reduced to a second-order partial differential equation for pressure on the meridional plane, then solved numerically in finite difference form. Our results indicate that the presence of a background jet can significantly modify the structures and dispersion characteristics of baroclinic Kelvin waves, depending on the speed and the spatial scales of the jet relative to those of the waves. The lowest baroclinic mode, which has a zonal phase speed much larger than typical mean flows, is the least structurally modified and Doppler-shifted. Higher baroclinic modes am more noticeably Doppler-shifted and experience str...