Elucidating the large bow-shaped feature on Venus: a numerical simuration was performed to analyze observational data of Akatsuki
The long-wave infrared camera (LIR) onboard the Venus Climate Orbiter Akatsuki detected an approximately 10,000 km bow-shaped feature spanning north to south. During the duration of four days of observation, this pattern remained almost in the same place, undisturbed by the eastern wind (super rotation) in Venus' atmosphere. Using a numerical simulation, we found that disturbunce at the lower atmosphere causes waves to propagate throughout the atmosphere. These waves spread from north to south and are conveyed to high altitudes. The bow-shaped feature of temperature was observed when these waves passed through the cloud top at 65 km altitude. This research has shown that it is possible to use measurements of the cloud tops on Venus to guess the state of the lower atmosphere.
Figure 1. Image of Venus photographed by Akatsuki in December 2015 © PLANET-C Project Team