A Long-lived Sharp Disruption on the Lower Clouds of Venus. (arXiv:2005.13540v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Peralta_J/0/1/0/all/0/1">J. Peralta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Navarro_T/0/1/0/all/0/1">T. Navarro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vun_C/0/1/0/all/0/1">C. W. Vun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanchez_Lavega_A/0/1/0/all/0/1">A. Sánchez-Lavega</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McGouldrick_K/0/1/0/all/0/1">K. McGouldrick</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Horinouchi_T/0/1/0/all/0/1">T. Horinouchi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Imamura_T/0/1/0/all/0/1">T. Imamura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hueso_R/0/1/0/all/0/1">R. Hueso</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boyd_J/0/1/0/all/0/1">J. P. Boyd</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schubert_G/0/1/0/all/0/1">G. Schubert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kouyama_T/0/1/0/all/0/1">T. Kouyama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Satoh_T/0/1/0/all/0/1">T. Satoh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Iwagami_N/0/1/0/all/0/1">N. Iwagami</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Young_E/0/1/0/all/0/1">E. F. Young</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bullock_M/0/1/0/all/0/1">M. A. Bullock</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Machado_P/0/1/0/all/0/1">P. Machado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_Y/0/1/0/all/0/1">Y. J. Lee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Limaye_S/0/1/0/all/0/1">S. S. Limaye</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nakamura_M/0/1/0/all/0/1">M. Nakamura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tellmann_S/0/1/0/all/0/1">S. Tellmann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wesley_A/0/1/0/all/0/1">A. Wesley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miles_P/0/1/0/all/0/1">P. Miles</a>
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$^{circ}$N–40$^{circ}$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 $sim$4.9
days faster than winds at this level ($sim$6-day period), alters clouds’
properties and aerosols, and remains coherent during weeks. Past observations
reveal its recurrent nature since at least 1983, and numerical simulations show
that a nonlinear Kelvin wave reproduces many of its properties.
Planetary-scale waves are thought to play a role in powering the
yet-unexplained atmospheric superrotation of Venus. Puzzlingly, while Kelvin,
Rossby and stationary waves manifest at the upper clouds (65–70 km), no
planetary-scale waves or stationary patterns have been reported in the
intervening level of the lower clouds (48–55 km), although the latter are
probably Lee waves. Using observations by the Akatsuki orbiter and ground-based
telescopes, we show that the lower clouds follow a regular cycle punctuated
between 30$^{circ}$N–40$^{circ}$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 $sim$4.9
days faster than winds at this level ($sim$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.
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