Atmospheric Dynamics and Vertical Structure of Uranus and Neptune’s Weather Layers
Atmospheric Dynamics and Vertical Structure of Uranus and Neptune’s Weather Layers
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天王星和海王星天气层的大气动力学和垂直结构
DOI：
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发表时间：
2019
影响因子：
10.3
通讯作者：
A. Sánchez‐Lavega
中科院分区：
文献类型：
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作者：
R. Hueso;A. Sánchez‐Lavega
冰巨人天王星和海王星有相似的自转周期，大的轨道倾角和强烈的纬向风在可见的云层水平。风被组织成三个广泛的急流：一个纬向急流，在低纬度地区流向西方，而在中纬度和高纬度地区，每个半球的单一急流流向东方。考虑到行星到太阳的距离很小，在云层中观察到的风的强度仍然是一个谜。这两颗行星都有低对比度的纬向带，与风的结构无关。它们也有黑暗的反气旋和明亮的云系，但在这些特征的丰富程度及其大小和纬度分布方面存在显着差异。在与甲烷云相容的高度上观测到这些带和主要气象系统，观测证据表明存在更深的硫化氢云，硫化氢和甲烷的纬度变化，高纬度甲烷耗尽，两极附近更容易检测到硫化氢。其他化学物质，如硫氢化氨和水，应该在几十到几百巴的压力下凝结形成深云。这两颗行星上的少量明亮特征是可能由甲烷冷凝提供动力的潮湿对流风暴的良好候选者。预计这些寒冷大气层中挥发物的深度丰度至少是木星和土星的10倍，使挥发物的全球分布成为确定大气稳定性的关键特征，也影响垂直风切变并抑制大型潮湿对流风暴的发展。深厚的巨大云层，微弱的太阳和内部热量强迫，极长的季节和有利于和反对潮湿对流的潜在影响的组合使这些行星处于动态状态，不同于太阳系中的任何其他行星。在这里，我们将探索在云层和这些行星的深层“天气层”观察到的气象学。我们表明，结合轨道和原位数据可能需要回答令人满意的突出问题，在这些大气的行为。
The Icy Giants Uranus and Neptune have similar rotation periods, large orbital inclinations and intense zonal winds at the visible cloud level. The winds are organized into three broad jets: a zonal jet that flows to the West at low latitudes and single jets that flow to the East in each hemisphere at mid and high-latitudes. The intensity of the winds observed at the cloud level remains a mystery considering the small energy available at the distance of the planets to the Sun. Both planets have zonal bands with low contrast that do not correlate with the structure of the winds. They also have dark anticyclones and bright cloud systems but present striking differences in the abundance of these features and their size and latitudinal distribution. The bands and major meteorological systems are observed at altitudes compatible with methane clouds and observational evidence suggests the presence of a deeper cloud of hydrogen sulfide and a latitudinal variation of hydrogen sulfide and methane with depletion of methane at high latitudes and more detectable hydrogen sulfide near the poles. Other chemical species like ammonia hydrosulfide and water should condense forming deep clouds at pressures of tens to hundreds of bars. A small number of bright features in both planets are good candidates for moist convective storms possibly powered by methane condensation. The expected deep abundances of volatiles in these cold atmospheres are at least 10 times larger than those on Jupiter and Saturn making the global distribution of volatiles a key feature to determine the stability of the atmosphere, influencing also the vertical wind shear and inhibiting the development of large moist convective storms. The combination of deep massive clouds, weak solar and internal heat forcing, extremely long seasons and potential effects in favor and against moist convection place these planets in a dynamic regime unlike any other in Solar System planets. Here we explore the observed meteorology at cloud level and the deep “weather layers” of these planets. We show that a combination of orbital and in situ data will probably be required to answer satisfactorily outstanding questions in the behavior of these atmospheres.
海王星上的新黑暗漩涡
DOI：
10.3847/1538-3881/aaa6d6
发表时间：
2018
期刊：
The Astronomical Journal
影响因子：
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作者：
Wong, Michael H.;Tollefson, Joshua;Hsu, Andrew I.;Pater, Imke de;Simon, Amy A.;Hueso, Ricardo;Sánchez-Lavega, Agustín;Sromovsky, Lawrence;Fry, Patrick;Luszcz-Cook, Statia
通讯作者：
Luszcz-Cook, Statia