IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2022A038 PROGRAM_TITLE The role of long-lived Waves and Instabilities in the Atmospheric Superrotation of Venus. PROGRAM_INV1 Javier Peralta PROGRAM_INV2 Daniela Espadinha PROGRAM_INV3 Pedro Machado PROGRAM_INV4 Eliot Young PROGRAM_INV5 Glenn Orton PROGRAM_SCICAT major planets / satellites PROGRAM_ABSTRACT_BEG The atmosphere of the planet Venus 'superrotates' about 60 times faster than the solid globe, an atmospheric phenomenon whose mechanism is not fully understood yet. Recent works have highlighted the important role that waves excited below the clouds may have in Venus's atmospheric circulation. Images of the lower clouds have revealed a disruption resembling a 'tsunami' interpreted as a new type of Kelvin wave bringing momentum from the deeper atmosphere. The lower clouds also exhibit giant long-lived shear waves and vortices with potential implications to the atmospheric circulation and aerosol distribution. Finally, images of the upper clouds unveiled abundant stationary waves which can substantially contribute to the total atmospheric torque that acts on the planet's surface. We propose a pioneering long-term program of observations of Venus with IRTF/SpeX to simultaneously monitor the genesis and development of these waves and instabilities in 3 dimensions during 25 days, allowing to infer a first-time global map of the superrotating winds above and below the clouds, monitor the evolution of the disruption, vortices and instabilities during about 4 revolutions of the lower clouds, and study the local hour dependence for the excitation and vertical propagation of the largest stationary wave on Venus. In addition, we propose other 3 days to observe Venus with MIRSI in coordination with expected observations by the bolometer LIR onboard JAXA's Akatsuki orbiter, in order to provide tools for a recalibration of the instrument and new corrections for the effects of a long-term degradation. PROGRAM_ABSTRACT_END