Saturn’s rings are known to show remarkable real time variability in their structure. Many of which can be associated to interactions with nearby moons and moonlets. Possibly the most interesting and dynamic place in the rings, probably in the whole Solar System, is the F ring. A highly disrupted ring with large asymmetries both radially and azimuthally. Numerically non-zero components to the curl of the velocity vector field (vorticity) in the perturbed area of the F ring post encounter are witnessed, significantly above the background vorticity. Within the perturbed area rich distributions of local rotations is seen located in and around the channel edges. The gravitational scattering of ring particles during the encounter causes a significant elevated curl of the vector field above the background F ring vorticity for the first 1–3 orbital periods post encounter. After 3 orbital periods vorticity reverts quite quickly to near background levels. This new found dynamical vortex life of the ring will be of great interest to planet and planetesimals in proto-planetary disks where vortices and turbulence are suspected of having a significant role in their formation and migrations. Additionally, it is found that the immediate channel edges created by the close passage of Prometheus actually show high radial dispersions in the order ~20–50 cm/s, up to a maximum of 1 m/s. This is much greater than the value required by Toomre for a disk to be unstable to the growth of axisymmetric oscillations. However, an area a few hundred km away from the edge shows a more promising location for the growth of coherent objects.

中文翻译：

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普罗米修斯在土星 F 环中引起涡度

众所周知，土星环在其结构中显示出显着的实时可变性。其中许多可能与与附近卫星和小卫星的相互作用有关。可能是环中最有趣和最有活力的地方，可能是整个太阳系，是 F 环。在径向和方位角都具有较大不对称性的高度破坏环。在 F 环柱遭遇的扰动区域中速度矢量场（涡度）的旋度的数值非零分量被目睹，明显高于背景涡度。在扰动区域内，可以看到位于通道边缘内和周围的局部旋转的丰富分布。在相遇后的前 1-3 个轨道周期内，环粒子在相遇期间的引力散射导致矢量场在背景 F 环涡旋上方显着升高。在 3 个轨道周期之后，涡度很快恢复到接近背景水平。这种新发现的环的动态涡旋生命将对原行星盘中的行星和星子产生极大的兴趣，其中涡旋和湍流被怀疑在它们的形成和迁移中起重要作用。此外，发现由 Prometheus 近距离通道产生的直接通道边缘实际上显示出大约 20–50 cm/s 的高径向扩散，最高可达 1 m/s。这比 Toomre 要求的值要大得多，因为磁盘对轴对称振荡的增长不稳定。然而，