[P-PS04] Recent advances in the science of Venus

[PPS04-P08] Superrotation variability and constituent variability at around the cloud-top of Venus

*Takeshi Horinouchi¹, Yeon Joo Lee² (1.Faculty of Environmental Earth Science, Hokkaido University, 2.Institute for Basic Science, Daejeon, South Korea)

Keywords:Venus, superrotation, SO2

It has been revealed that the zonal winds at around the cloud-top of Venus exhibit rich long-term variability over broad time scales by using cloud-tracking with ultraviolet images from Venus Express and Akatsuki. Here we investigate possible co-variability in the zonal wind speed and the abundance of constituents such as SO2, mainly by comparing our cloud-tracking results with published papers. Our analysis does not suggest an existence of a coherent co-variability between the superrotation speed and the SO2 abundance. No clear long-term relationship was found between the near cloud-top day-side winds (obtained from the 283- or 365-nm images; both results are similar) and the global mean SO2 gas abundance at 62 km altitude retrieved from the ground-based day-and-night observations throughout the years in 2016-2022. Also, we did not find a local correlation between the 283-nm albedo (which is affected by the absorption by SO2) and the 283–365-nm wind difference. There is a weak co-variability between the superrotation speed and the near cloud-top H2O abundance, but the observational records are too few to conclude it.