We analyse the linear stability of filaments of uniform potential vorticity with a horizontal axis in a quasi-geostrophic flow. For a single filament, the situation corresponds to the simplest three-dimensional shear zone in a rapidly rotating, continuously stably stratified fluid. Yet, this has not been formally addressed to our knowledge. We show that the filament is sensitive to the Kelvin–Helmholtz instability for perturbations in a finite range of streamwise wavenumbers , similarly to the classical situation of a two-dimensional strip of uniform vorticity. We also analyse the stability of a jet formed by two parallel filaments of opposite PV whose axes are located on the same horizontal plane as well as the stability of “hetonic” filaments. Hetonic filaments consist of a pair of opposite PV filaments located at different heights. These can be sensitive to baroclinic instabilities over a wide range of longitudinal wavenumbers.

中文翻译：

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均匀准地转位涡细丝的稳定性

我们分析了准地转流中具有水平轴的均匀势涡细丝的线性稳定性。对于单丝，这种情况对应于快速旋转、连续稳定分层的流体中最简单的三维剪切带。然而，据我们所知，这尚未正式解决。我们表明，细丝对有限流向波数范围内的扰动的开尔文-亥姆霍兹不稳定性敏感，类似于二维均匀涡度带的经典情况。我们还分析了由两个相反 PV 的平行细丝形成的射流的稳定性，这些细丝的轴位于同一水平面上，以及“hetonic”细丝的稳定性。Hetonic 灯丝由位于不同高度的一对相对的 PV 灯丝组成。