Instantaneous three-dimensional thermal structure of the South Polar Vortex of Venus
Instantaneous three-dimensional thermal structure of the South Polar Vortex of Venus
复制标题
金星南极涡旋瞬时三维热结构
DOI：
10.1016/j.icarus.2014.09.030
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发表时间：
2024
期刊：
影响因子：
3.2
通讯作者：
A. Sánchez‐Lavega
中科院分区：
文献类型：
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作者：
I. Garate;A. G. Muñoz;R. Hueso;A. Sánchez‐Lavega
金星的热辐射光谱显示出CO2吸收带的特征。通过反演技术，这些波段能够反演大气温度分布。我们已经分析了VIRTIS-M-IR夜侧数据，获得了金星南极地区55和85公里高度之间的高分辨率热图。这种分析是特定于三个金星快车轨道的旋涡呈现不同的动力学配置。冷环的中心高度约为100毫巴（102 km）。平均而言，冷环比极点冷15 K以上，但其具体温度随时间而变化。在所研究的三个轨道中，南极涡旋似乎是一个靠近极点的垂直延伸的热区，在高度55和67公里之间受到冷环的挤压，但在大约74公里处向赤道方向扩散。瞬时温度图和它们的纬向平均值都表明，来自涡旋的热信号的最高高度极限是在1080公里的高度，至少在行星的黑夜一侧是这样。大气层的上部（67-85公里）比较均匀，在2000公里的水平距离上有大约25 K的长尺度水平温差。较低的部分（55-67公里）显示出更精细的尺度结构，形成了涡旋形态，在相同的高度范围内和1500公里的水平距离上，热差异高达约50 K。大气的这一下部受上层云层的影响很大，导致更强的局部温度变化和更大的不确定性。根据温度图，我们还研究了三种涡旋位形在不同大气层的垂直稳定度。在所考虑的高度范围内（55-85 km）和在整个极涡中，静力稳定度始终为正（ST> 0）。冷领是极纬最稳定的垂直结构，而涡旋和副极纬的稳定度值较低。此外，存在于涡流内的热细丝表现出比其周围环境更低的稳定性值。62至67公里之间的层是最稳定的。这些结果与以前的无线电掩星分析的结论是一致的。
The Venus thermal radiation spectrum exhibits the signature of CO2absorption bands. By means of inversion techniques, those bands enable the retrieval of atmospheric temperature profiles. We have analyzed VIRTIS-M-IR night-side data obtaining high-resolution thermal maps of the Venus south polar region between 55 and 85 km altitudes. This analysis is specific to three Venus Express orbits where the vortex presents different dynamical configurations. The cold collar is clearly distinguishable centered at ∼62 km (∼100 mbar) altitude level. On average, the cold collar is more than 15 K colder than the pole, but its specific temperature varies with time. In the three orbits under investigation the South Polar Vortex appears as a vertically extended hot region close to the pole and squeezed by the cold collar between altitudes 55 and 67 km but spreading equatorwards at about 74 km. Both the instantaneous temperature maps and their zonal averages show that the top altitude limit of the thermal signature from the vortex is at ∼80 km altitude, at least on the night-side of the planet. The upper part of the atmosphere (67–85 km) is more homogeneous and has long-scale horizontal temperature differences of about 25 K over horizontal distances of ∼2000 km. The lower part (55–67 km) shows more fine-scale structure, creating the vortex morphology, with thermal differences of up to about 50 K over the same altitude range and ∼500 km horizontal distances. This lower part of the atmosphere is highly affected by the upper cloud deck, leading to stronger local temperature variations and larger uncertainties in the retrieval. From the temperature maps, we also study the vertical stability of different atmospheric layers for the three vortex configurations. The static stability is always positive (ST> 0) in the considered altitude range (55–85 km) and in the whole polar vortex. The cold collar is the most vertically stable structure at polar latitudes, while the vortex and sub-polar latitudes show lower stability values. Furthermore, the hot filaments present within the vortex exhibit lower stability values than their surroundings. The layer between 62 and 67 km resulted to be the most stable. These results are in good agreement with conclusions from previous radio occultation analyses.
影响因子：
--
作者：
I. Dmitrenko;S. Kirillov;V. Ivanov;R. Woodgate;I. Polyakov;Nikolay Koldunov;L. Fortier;C. Lalande-C.-Lalan
通讯作者：
I. Dmitrenko;S. Kirillov;V. Ivanov;R. Woodgate;I. Polyakov;Nikolay Koldunov;L. Fortier;C. Lalande-C.-Lalan
影响因子：
2.4
作者：
Haus, R.;Kappel, D.;Arnold, G.
通讯作者：
Arnold, G.
影响因子：
3.2
作者：
Haus, R.;Kappel, D.;Arnold, G.
通讯作者：
Arnold, G.