11:20 AM - 11:35 AM
[PPS06-08] Stationary features at the Venus cloud top seen in Akatsuki/IR2 2.02-μm dayside images
Keywords:Venus, atmosphere, Akatsuki, Stationary feature
In order to obtain a better understanding of the newly discovered stationary structure, we have analyzed 2.02-μm dayside images taken by 2-μm Camera named IR2. Since a wavelength of 2.02 μm locates in a CO2 absorption band, the images enable us to monitor the spatiotemporal variation of cloud top altitude. Up to the present, we have detected three stationary features in the images taken on (a) April 25, (b) May 15-25, and (c) June 21-22. Although these features are spatially localized compared with the planetary-scale bow-shaped structure by LIR, interestingly, all of them have bow-like structure and appear in a position above highlands (i.e., Atta Regio, Beta Regio, and Alpha Regio for cases (a), (b), and (c), respectively). Local time of their occurrence is in 11-14 h, which is different from each other.
In this presentation, we will show the stationary features detected in the 2.02-μm dayside images ever before and initial results using a cloud-tracking method, and also report on whether such features are also seen in simultaneously-obtained images by the other cameras.