[P-PS05] Science of Venus: knowing more about the earth's sister planet

[PPS05-10] Mean winds and planetary-scale waves at the cloud top of Venus from the 6-year observation of Akatsuki/UVI

*堀之内 武¹、神山 徹²、今井 正尭³、Lee Yeon Joo⁴、村上 真也⁵、渡部 重十⁶、山田 学⁷、山崎 敦⁵ (1.北海道大学地球環境科学研究院、2.産総研、3.京都産業大学、4.Institute for Basic Science、5.宇宙研、6.北海道情報大学、7.千葉工大)

キーワード：Venus、Wind、Wave

Akasuki has been in operation since its orbital insertion in Dec 2015, and UVI onboard Akatsuki has been nearly continuously observing dayside UV radiance from around the cloud top. Horinouchi et al (2018) documented the mean winds and their variations obtained over the first ~1.5 years. Here, we update the study with the observation until 2021, and we further report long-term statistics of planetary-scale waves, updating the case study of Imai et al (2019). The topics include hemispheric asymmetry and its variability, long-term and low-frequency variations of the superrotation, thermal tides, and statistics of the Rossby and the equatorial Kelvin waves.

References:
Horinouchi, T., T. Kouyama, Y. J. Lee, S. Murakami, K. Ogohara, M. Takagi, T. Imamura,K. Nakajima, J. Peralta, A. Yamazaki, M. Yamada, and S. Watanabe (2018). Mean winds at the cloud top of Venus obtained from two-wavelength UV imaging by Akatsuki. Earth, Planets, Space, 70:10. https://doi.org/10.1186/s40623-017-0775-3

Imai, M., Kouyama, T., Takahashi, Y., Yamazaki, A., Watanabe, S., Yamada, M., Imamura, T., Satoh, T., Nakamura, M., Murakami, S., Ogohara, K., and Horinouchi, T. (2019). Planetary-scale variations in winds and UV brightness at the Venusian cloud top: Periodicity and temporal evolution. J. Geophys. Res.: Planets, 124(10), 2635-2659. https://doi.org/10.1029/2019JE006065