An asymptotic model for the propagation of oceanic internal tides through quasi-geostrophic flow
An asymptotic model for the propagation of oceanic internal tides through quasi-geostrophic flow
复制标题
通过准地转流传播海洋内潮汐的渐近模型
DOI：
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发表时间：
2016
影响因子：
3.7
通讯作者：
W. Young
中科院分区：
文献类型：
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作者：
G. Wagner;Gwenael Ferrando;W. Young
我们从描述惯性重力内波通过准地转流传播的流体静力Boussinesq方程推导出一个时间平均的“流体静力波动方程”。推导使用多尺度渐近方法隔离波场演化的时间间隔远长于波周期，假设波场有一个明确的非惯性频率，如中纬度半日月球潮汐，假设波场和准地转流具有可比的空间尺度和忽略非线性波-波动力学。因此，流体静力波动方程是一个简化的模型，适用于大规模内潮通过不均匀和运动的海洋的传播。与线性化和流体静力Boussinesq方程的数值比较证明了流体静力波动方程模型的有效性，并说明了当准地转流太强和波频率太接近惯性时，模型是如何失败的。流体静力学波动方程为建立海洋内潮与准地转涡旋和海流之间的能量传递耦合模式迈出了第一步。
We derive a time-averaged ‘hydrostatic wave equation’ from the hydrostatic Boussinesq equations that describes the propagation of inertia–gravity internal waves through quasi-geostrophic flow. The derivation uses a multiple-scale asymptotic method to isolate wave field evolution over intervals much longer than a wave period, assumes the wave field has a well-defined non-inertial frequency such as that of the mid-latitude semi-diurnal lunar tide, assumes that the wave field and quasi-geostrophic flow have comparable spatial scales and neglects nonlinear wave–wave dynamics. As a result the hydrostatic wave equation is a reduced model applicable to the propagation of large-scale internal tides through the inhomogeneous and moving ocean. A numerical comparison with the linearized and hydrostatic Boussinesq equations demonstrates the validity of the hydrostatic wave equation model and illustrates how the model fails when the quasi-geostrophic flow is too strong and the wave frequency is too close to inertial. The hydrostatic wave equation provides a first step toward a coupled model for energy transfer between oceanic internal tides and quasi-geostrophic eddies and currents.
影响因子：
3.7
作者：
Jin-Han Xie;J. Vanneste
通讯作者：
Jin-Han Xie;J. Vanneste