The Influence of Topography on the Stability of Shelfbreak Fronts
The Influence of Topography on the Stability of Shelfbreak Fronts
复制标题
地形对断架前沿稳定性的影响
DOI：
10.1175/jpo2717.1
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发表时间：
2005
影响因子：
3.5
通讯作者：
Mark S. C. Reed
中科院分区：
文献类型：
--
作者：
M. Lozier;Mark S. C. Reed
为了了解以水平和垂直连续剪切为特征的搁板锋面稳定性受地形影响的程度，对一系列锋面射流和底坡构型进行了线性稳定性分析。利用线性化的流体静力学原始方程，研究了叠加在连续层状防护层锋面上的三维摄动。对于研究中的所有模型，作为斜压气流增长最快的模式，锋面不稳定模式不受底部的影响：逆行、顺行和平底急流都具有相同的稳定性特征。相比之下，弱斜压急流受底部地形的影响较大。底坡的存在稳定了前进射流，破坏了逆行射流的稳定，这种差异归因于等轴线相对于底部斜坡的方向不同。底部斜率和/或背景层结的时间和/或下游变化对弱斜压急流的不稳定性产生了显着的变化。
In an attempt to understand the degree to which the stability of a shelfbreak front, characterized by continuous horizontal and vertical shear, is affected by topography, a linear stability analysis was conducted for a range of frontal jets and bottom-slope configurations. Three-dimensional perturbations superposed on a continuously stratified shelfbreak front were investigated using linearized, hydrostatic primitive equations. For all model runs in the study, the frontal instability mode, which is the fastest-growing mode for a baroclinic flow, was not influenced by the bottom: Retrograde, prograde, and flat-bottom jets all share the same stability characteristics. In contrast, weakly baroclinic jets are strongly influenced by bottom topography. The presence of a bottom slope stabilizes prograde jets and destabilizes retrograde jets, a difference attributed to the orientation of the isopycnals relative to the bottom slope. Temporal and/or downstream changes in the bottom slope and/or background stratification are shown to produce sizeable changes in the instability of a weakly baroclinic jet.