Stationary features at the cloud top of Venus observed by Ultraviolet Imager onboard Akatsuki
Stationary features at the cloud top of Venus observed by Ultraviolet Imager onboard Akatsuki
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晓号上的紫外线成像仪观测到金星云顶的静止特征
DOI：
10.1029/2018je005842
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
et al.
中科院分区：
文献类型：
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作者：
Takehiko Kitahara;Takeshi Imamura;Takao M. Sato;Atsushi Yamazaki;Yeon Joo Lee;et al.
利用赤月卫星上搭载的紫外线成像仪（UVI） 283 nm通道，在金星云顶发现了指示地形重力波的静止特征，并研究了它们与地理和当地时间的相关性。在这个波长上，二氧化硫的吸收占主导地位。为了提取相对于表面的固定结构，我们对多幅图像进行平均以平滑移动特征，并应用高通滤波来强调小结构。我们发现，静止地物只出现在高地上空，而且往往出现在中午和晚上之间。静止特征似乎与长波红外相机（LIR）拍摄的云顶温度图中观测到的特征是同步的。利用重力波模型表明，so2的尺度高度应小于云顶周围云的尺度高度，以再现紫外成像仪和长波红外相机图像中观测到的静止特征之间的相位关系。
Stationary features indicative of topographic gravity waves were identified at the cloud top of Venus with the 283‐nm channel of the Ultraviolet Imager (UVI) onboard Akatsuki, and their geographical and local time dependences were studied. At this wavelength the absorption by SO2dominates. To extract stationary structures with respect to the surface, we averaged multiple images to smooth out moving features and applied high‐pass filtering to emphasize small structures. We found that stationary features appear exclusively above highlands and that they tend to appear between noon and evening. The stationary features seem to be synchronized with those observed in the cloud top temperature maps taken by the Longwave Infrared Camera (LIR). It was shown using a gravity wave model that the scale height of SO2should be smaller than that of the cloud around the cloud top to reproduce the observed phase relationship between the stationary features seen in the Ultraviolet Imager and Longwave Infrared Camera images.