Evidence for methane escape and strong seasonal and dynamical perturbations of Neptune's atmospheric temperatures
Evidence for methane escape and strong seasonal and dynamical perturbations of Neptune's atmospheric temperatures
复制标题
甲烷逃逸以及海王星大气温度的强烈季节性和动态扰动的证据
DOI：
10.1051/0004-6361:20078277
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发表时间：
2007
影响因子：
6.5
通讯作者：
A. Friedson
中科院分区：
文献类型：
--
作者：
G. Orton;T. Encrenaz;C. Leyrat;R. Puetter;A. Friedson
目标。我们研究了海王星中红外热辐射的分布，以确定温度的空间变异性和微量成分的分布，使我们能够确定其大气中辐射和动力学的相对强度。方法. 2006年9月1日至2日，甚大望远镜拍摄了这颗行星的中红外图像。结果这些图像揭示了热发射的强烈不均匀性。17.6和18.7-µm图像显示海王星对流层顶附近的南极温度季节性升高。这些高温使对流层甲烷，在其他地方冷困在深处，逃逸到平流层。平流层甲烷和乙烷向极地70 ° S、8.6和12.3 µm的辐射增强，65-70 ° S纬度附近的平流层有一个明显的暖特征随中性大气旋转。该特征可以
Aims. We studied the distribution of mid-infrared thermal emission from Neptune to determine the spatial variability of temperatures and the distribution of trace constituents, allowing us to determine the relative strengths of radiation and dynamics in its atmosphere. Methods. Mid-infrared images of the planet were taken at the Very Large Telescope on 1–2 September 2006. Results. These images reveal strong inhomogeneities in thermal emission. 17.6 and 18.7-µm images exhibit strong seasonally elevated south polar temperatures near Neptune’s tropopause. These high temperatures allow tropospheric methane, elsewhere cold-trapped at depth, to escape into the stratosphere. Poleward of 70 ◦ S, 8.6- and 12.3-µm emission from stratospheric methane and ethane is enhanced, and a distinct, warm stratospheric feature near 65–70 ◦ S latitude is rotating with the neutral atmosphere. This feature may