South-polar features on Venus similar to those near the north pole
South-polar features on Venus similar to those near the north pole
复制标题
金星的南极特征与北极附近相似
作者：
G. Piccioni;P. Drossart;A. Sánchez‐Lavega;R. Hueso;F. Taylor;C. Wilson;D. Grassi;L. Zasova;M. Moriconi;A. Adriani;S. Lebonnois;A. Coradini;B. Bézard;F. Angrilli;G. Arnold;K. Baines;G. Bellucci;J. Benkhoff;J. Bibring;A. Blanco;M. Błęcka;R. Carlson;A. Lellis;T. Encrenaz;S. Erard;S. Fonti;V. Formisano;T. Fouchet;R. García;R. Haus;J. Helbert;N. Ignatiev;P. Irwin;Y. Langevin;M. López‐Valverde;D. Luz;L. Marinangeli;V. Orofino;A. Rodin;M. Roos‐Serote;B. Saggin;D. Stam;D. Titov;G. Visconti;M. Zambelli
金星没有季节，自转缓慢，大气层非常厚重，主要是二氧化碳，云层主要是硫酸液滴。以前的金星任务的红外观测揭示了一个明亮的“偶极子”特征，在其北极被一个冷的“项圈”包围。极偶极子是一个巨大的漩涡中心的“双眼”特征，围绕着极点旋转，可能与快速下降流有关。极地冷环是一条宽而浅的冷空气河，围绕极地涡旋循环。一个悬而未决的问题是全球环流是否对称，以至于南极存在偶极子特征。在这里，我们报告的观测金星的南极地区，我们已经看到云的形态很像那些围绕北极，但旋转速度略快于北方偶极子。涡旋可能向下延伸到约50公里高度的低云层，也许更深。南极周围云层的光谱特性与硫酸成分是一致的。
Venus has no seasons, slow rotation and a very massive atmosphere, which is mainly carbon dioxide with clouds primarily of sulphuric acid droplets. Infrared observations by previous missions to Venus revealed a bright ‘dipole’ feature surrounded by a cold ‘collar’ at its north pole. The polar dipole is a ‘double-eye’ feature at the centre of a vast vortex that rotates around the pole, and is possibly associated with rapid downwelling. The polar cold collar is a wide, shallow river of cold air that circulates around the polar vortex. One outstanding question has been whether the global circulation was symmetric, such that a dipole feature existed at the south pole. Here we report observations of Venus’ south-polar region, where we have seen clouds with morphology much like those around the north pole, but rotating somewhat faster than the northern dipole. The vortex may extend down to the lower cloud layers that lie at about 50 km height and perhaps deeper. The spectroscopic properties of the clouds around the south pole are compatible with a sulphuric acid composition.