Seasonal Evolution of Titan's Stratosphere Near the Poles
Seasonal Evolution of Titan's Stratosphere Near the Poles
复制标题
两极附近泰坦平流层的季节演变
DOI：
10.3847/2041-8213/aaadbd
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
F. Flasar
中科院分区：
文献类型：
--
作者：
A. Coustenis;D. Jennings;R. Achterberg;R. Achterberg;G. Bampasidis;C. Nixon;P. Lavvas;V. Cottini;V. Cottini;F. Flasar
在这封信中，我们报告了对泰坦两极附近季节演变的监测。我们发现土卫六南极自 2010 年以来出现了强烈的温度下降，并且一些痕量物质显着增加，例如以前仅在北高纬度地区观察到的复杂碳氢化合物和腈（特别是 HC3N 和 C6H6）。这是由于土卫六北部从冬季（2002 年）到夏季（2017 年）的季节变化造成的，同时南极也进入了冬季。在这个过渡时期，化学寿命较长的大气成分在北部徘徊，经历缓慢的光化学破坏，而寿命较短的大气成分则减少并重新出现在南部。预计北部会出现相反的影响，但直到现在才确切地观察到。我们在这里对卡西尼/卡西尼复合红外光谱仪过去几年获得的高分辨率天底光谱进行了分析，并描述了土卫六两极附近的温度和成分变化。从2013年到2016年，北极地区的气温上升了10 K，而南半球地区在相似的时间内却出现了更显着的下降（最高25 K）。虽然自 2012 年左右以来，南极地区的化学含量不断增强，但自 2015 年以来，北部的大多数分子的化学含量最终显示出明显的减少。这表明土卫六平流层对季节的非对称响应，可以对光化学和 GCM 模型设置限制。
In this Letter, we report the monitoring of seasonal evolution near Titan’s poles. We find Titan’s south pole to exhibit since 2010 a strong temperature decrease and a dramatic enhancement of several trace species such as complex hydrocarbons and nitriles (HC3N and C6H6 in particular) previously only observed at high northern latitudes. This results from the seasonal change on Titan going from winter (2002) to summer (2017) in the north and, at the same time, the onset of winter in the south pole. During this transition period atmospheric components with longer chemical lifetimes linger in the north, undergoing slow photochemical destruction, while those with shorter lifetimes decrease and reappear in the south. An opposite effect was expected in the north, but not observed with certainty until now. We present here an analysis of high-resolution nadir spectra acquired by Cassini/Cassini Composite Infrared Spectrometer in the past years and describe the temperature and composition variations near Titan’s poles. From 2013 until 2016, the northern polar region has shown a temperature increase of 10 K, while the south has shown a more significant decrease (up to 25 K) in a similar period of time. While the south polar region has been continuously enhanced since about 2012, the chemical content in the north is finally showing a clear depletion for most molecules only since 2015. This is indicative of a non-symmetrical response to the seasons in Titan’s stratosphere that can set constraints on photochemical and GCM models.
泰坦平流层中远红外雾霾的季节性消失
DOI：
10.1088/2041-8205/754/1/l3
发表时间：
2012
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Jennings D
通讯作者：
Jennings D
卡西尼号任务期间泰坦平流层的热结构和化学结构变化
DOI：
10.1088/0004-637x/760/2/144
发表时间：
2012
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Bampasidis G
通讯作者：
Bampasidis G