Abstract—

The equator of Saturn is inclined to the orbital plane by an angle of 26.75°, and the period of revolution around the Sun is 29.45 years. Since the orbital eccentricity of Saturn is e ≈ 0.056 and Saturn passes the perihelion and the aphelion during the summer epoch in its southern and northern hemispheres, respectively, the southern hemisphere receives 25% more energy from the Sun than the northern one. This factor influences the physical characteristics and vertical structure of the atmosphere. Changes on Saturn were registered and they were related to the seasonal influx of the solar energy. To analyze the effect, the results of observations at the equinox moments in 1966, 1980, 1995, and 2010 were used. Latitudinal differences in the absorption by methane across the disk showed a significant asymmetry between the northern and southern hemispheres. Moreover, in the opposite hemispheres, the absorption changes in different ways. Under identical conditions formed in the previous history of the planet in 1966 and 1995, the absorption in the northern summer hemisphere was greater than that in the southern one. A reverse effect was observed in 1980 when the absorption was large in the southern summer hemisphere. The last equinox on Saturn was in 2009. It is supposed that its effect would be similar to the results of 1980. However, in contrast to the pronounced asymmetry in absorption between the hemispheres in 1966, 1980, and 1995, hardly any difference in absorption between the hemispheres was observed during the 2009 equinox. Moreover, in the northern winter hemisphere, the absorption did not decrease, while it markedly increased in the summer southern hemisphere. A peculiar feature of the 2009 equinox itself was that, unlike the previous three equinoxes, it occurred during the solar activity minimum. A joint analysis of the results of observations performed in 1980 and 2010 by the Voyager and Cassini probes, respectively, showed that, for one Saturnian year, the tropical atmosphere in the tropopause warmed up by 10 K. Taking into account these differences and the fact that the solar activity index in 1980 and 2010 was R = 0 and more than 150, respectively, the radiative constant of the hydrogen–helium atmosphere of Saturn is estimated at ~4.5 terrestrial years. However, the warming in the tropopause changed the atmospheric stratification and the stability and influenced the large-scale dynamics of the upper troposphere in 2010.

中文翻译：

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土星2010年春分的特征

摘要-

土星的赤道相对于轨道平面倾斜26.75°角，绕太阳公转的周期为29.45年。由于土星的轨道离心率是e≈0.056，并且在夏季，土星在南半球和北半球分别通过近日点和顶点，南半球比北半球从太阳获得的能量多25％。该因素影响大气的物理特性和垂直结构。土星的变化被记录下来，并且与太阳能的季节性涌入有关。为了分析这种影响，我们使用了1966、1980、1995和2010年春分时刻的观测结果。整个圆盘上甲烷吸收的纬度差异表明，北半球和南半球之间存在明显的不对称性。而且，在相对的半球中，吸收以不同的方式变化。在1966年和1995年地球先前历史形成的相同条件下，夏季北半球的吸收大于南部的吸收。在1980年，当南半球的吸收量很大时，观察到了相反的效果。土星上的最后一个春分点是在2009年。它的影响可能与1980年的结果相似。但是，与1966年，1980年和1995年的半球之间明显的吸收不对称相反，吸收的差异几乎没有在2009年春分期间观察到了半球之间的距离。而且，在北半球冬季，吸收没有减少，而在南半球夏季，吸收明显增加。2009年春分本身的一个特殊特征是，与之前的三个春分不同，它发生在太阳活动最小期间。Voyager和Cassini的探测分别表明，在土星一年中，对流层顶的热带大气升温了10K。考虑到这些差异以及1980年和2010年太阳活动指数为R = 0和更高的事实，土星的氢-氦气大气的辐射常数分别超过150，估计为约4.5陆地年。但是，对流层顶的变暖改变了大气层化和稳定性，并影响了2010年对流层上层的大规模动力学。