Near-Inertial Wave Propagation In Geostrophic Shear
Near-Inertial Wave Propagation In Geostrophic Shear
复制标题
DOI：
10.1175/1520-0485(1985)015
复制
发表时间：
1985-05
影响因子：
3.5
通讯作者：
E. Kunze
中科院分区：
文献类型：
--
作者：
E. Kunze
摘要本文给出了地转切变中近惯性内波传播的近似频散关系，其中考虑了平均流切变的应变。近惯性运动和地转运动在海洋中具有相似的水平尺度。这意味着运动方程中必须保留涉及（v·Δ）V形式的平均流剪切力以及平均流本身[（V·Δ）v]的相互作用项。涡量的增加使内波段的下限从行星的科里奥利频率f移动到有效的科里奥利频率feπ = f + π/2。采用射线追踪方法研究了近惯性波在地转急流中的传播特性。捕获和放大发生在负涡度区域，在那里近惯性波的固有频率0可以小于周围海洋的有效科里奥利频率。在上层海洋负涡度的底部观测到了强烈的向下传播的近惯性波。
Abstract An approximate dispersion relation for near-inertial internal waves propagating in geostrophic shear is formulated that includes straining by the mean flow shear. Near-inertial and geostrophic motions have similar horizontal scales in the ocean. This implies that interaction terms involving mean flow shear of the form (v·Δ)V as well as the mean flow itself [(V·Δ)v] must be retained in the equations of motion. The vorticity ζ shifts the lower bound of the internal waveband from the planetary value of the Coriolis frequency f to an effective Coriolis frequency feπ = f + ζ/2. A ray tracing approach is adopted to examine the propagation behavior of near-inertial waves in a model geostrophic jet. Trapping and amplification occur in regions of negative vorticity where near-inertial waves' intrinsic frequency 0 can be less than the effective Coriolis frequency of the surrounding ocean. Intense downward-propagating near-inertial waves have been observed at the base of upper ocean negative vorticity...