The weather layers of the gas giant planets, Jupiter and Saturn, comprise the shallow atmospheric layers that are influenced energetically by a combination of incoming solar radiation and localised latent heating of condensates, as well as by upwelling heat from their planetary interiors. They are also the most accessible regions of those planets to direct observations. Recent analyses in Oxford of cloud-tracked winds on Jupiter have demonstrated that kinetic energy is injected into the weather layer at scales comparable to the Rossby radius of deformation and cascades both upscale, mostly into the extra-tropical zonal jets, and downscale to the smallest resolvable scales in Cassini images. The large-scale flow on both Jupiter and Saturn appears to equilibrate towards a state which is close to marginal instability according to Arnol’d’s 2nd stability theorem. This scenario is largely reproduced in a hierarchy of numerical models of giant planet weather layers, including relatively realistic models which seek to predict thermal and dynamical structures using a full set of parameterisations of radiative transfer, interior heat sources and even moist convection. Such models include (amongst others) the Jason GCM, developed in Oxford, which also represents the formation of (energetically passive) clouds of NH3, NH4SH and H2O condensates and the transport of condensable tracers. Recent results show some promise in comparison with observations from the Cassini and Juno missions, but some observed features (such as Jupiter’s Great Red Spot and other compact ovals) are not yet captured spontaneously by most weather layer models. We review recent work in this vein and discuss a number of open questions for future study.

中文翻译：

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木星和土星天气层的湍流动力：秩序混乱吗？

气体巨型行星的木星和土星的天气层包括浅层大气层，这些大气层受到传入的太阳辐射和凝结水的局部潜热以及行星内部热量上升的综合影响。它们还是这些行星中最容易观察的区域。牛津大学最近对木星上的云迹风的分析表明，动能以与罗斯比形变半径相当的尺度注入天气层，并且在较高级（主要是向温带纬向射流和向下级到最小）级联卡西尼号图像中的可分辨比例。根据Arnol'd的第二个稳定性定理，木星和土星上的大规模流动似乎都趋向于接近边缘不稳定的状态。这种情况在很大程度上由巨型行星天气层的数值模型层次结构再现，包括相对逼真的模型，这些模型试图使用辐射传递，内部热源甚至潮湿对流的全套参数化来预测热和动力结构。这些模型包括牛津大学开发的Jason GCM（以及其他模型），该模型也代表了NH3，NH4SH和H2O冷凝水（能量被动）云的形成以及可凝结示踪剂的传输。最新的结果与卡西尼号和朱诺号任务的观测结果相比，显示出一些希望，但是大多数天气图层模型尚未自发捕获某些观测到的特征（如木星的大红色斑点和其他紧凑的椭圆形）。我们以这种方式回顾了最近的工作，并讨论了一些未解决的问题，以供将来研究。