A Long-lived Sharp Disruption on the Lower Clouds of Venus
Planetary-scale waves are thought to play a role in powering the yet-unexplained atmospheric superrotation of Venus.
Puzzlingly, while Kelvin, Rossby and stationary waves manifest at the upper clouds (65–70 km), no planetary-scale waves or stationary patterns have been reported in the intervening level of the lower clouds (48–55 km), although the latter are probably Lee waves.
Using observations by the Akatsuki orbiter and ground-based telescopes, we show that the lower clouds follow a regular cycle punctuated between 30∘N–40∘S by a sharp discontinuity or disruption with potential implications to Venus’s general circulation and thermal structure. This disruption exhibits a westward rotation period of ∼4.9 days faster than winds at this level (∼6-day period), alters clouds’ properties and aerosols, and remains coherent during weeks.
Past observations reveal its recurrent nature since at least 1983, and numerical simulations show that a nonlinear Kelvin wave reproduces many of its properties.
J. Peralta, T. Navarro, C. W. Vun, A. Sánchez-Lavega, K. McGouldrick, T. Horinouchi, T. Imamura, R. Hueso, J. P. Boyd, G. Schubert, T. Kouyama, T. Satoh, N. Iwagami, E. F. Young, M. A. Bullock, P. Machado, Y. J. Lee, S. S. Limaye, M. Nakamura, S. Tellmann, A. Wesley, P. Miles
Comments: 21 pages, 10 figures, 2 animated figures and 2 tables
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Atmospheric and Oceanic Physics (physics.ao-ph)
Journal reference: Geophysical Research Letters, Volume 47, Issue 11, 16 June 2020, e2020GL087221
DOI: 10.1029/2020GL087221
Cite as: arXiv:2005.13540 [astro-ph.EP] (or arXiv:2005.13540v1 [astro-ph.EP] for this version)
Submission history
From: Javier Peralta
[v1] Wed, 27 May 2020 17:23:15 UTC (36,195 KB)
https://arxiv.org/abs/2005.13540
