Saturn’s rotation period from its atmospheric planetary-wave configuration
Saturn’s rotation period from its atmospheric planetary-wave configuration
复制标题
土星的自转周期来自其大气行星波结构
DOI：
10.1038/nature08194
复制
发表时间：
2009
期刊：
影响因子：
64.8
通讯作者：
Gerald Schubert
中科院分区：
文献类型：
--
作者：
P. L. Read;T. Dowling;Gerald Schubert
气体巨星磁场的旋转周期（称为系统III参考系）通常被用来推断其整体旋转。土星的偶极磁场相对于其自转轴并不倾斜（不像木星、天王星和海王星），因此其长波（千米）辐射的替代测量目前被用来固定系统III的自转周期。卡西尼号探测器现在测量的周期比旅行者号28年前测量的10小时39分24秒的值长了1.77分钟。在这里，我们报告确定土星的旋转周期的基础上分析的位涡。由此产生的参考系（我们称之为系统IIIw）以10 h 34 min 13 ± 20 s的周期旋转。这种移动的参考系与土星上交替的喷流模式一致，这种模式在东向和向西向流动之间更加对称。这表明土星的风比迄今为止所认为的更像木星的风。
The rotation period of a gas giant's magnetic field (called the System III reference frame) is commonly used to infer its bulk rotation. Saturn's dipole magnetic field is not tilted relative to its rotation axis (unlike Jupiter, Uranus and Neptune), so the surrogate measure of its long-wavelength (kilometric) radiation is currently used to fix the System III rotation period. The period as measured now by the Cassini spacecraft is up to ∼7 min longer than the value of 10 h 39 min 24 s measured 28 years ago by Voyager. Here we report a determination of Saturn's rotation period based on an analysis of potential vorticity. The resulting reference frame (which we call System IIIw) rotates with a period of 10 h 34 min 13 ± 20 s. This shifted reference frame is consistent with a pattern of alternating jets on Saturn that is more symmetrical between eastward and westward flow. This suggests that Saturn's winds are much more like those of Jupiter than hitherto believed.