Amateur Observers Witness the Return of Venus’ Cloud Discontinuity

Firstly identified in images from JAXA’s orbiter Akatsuki, the cloud discontinuity of Venus is a planetary-scale phenomenon known to be recurrent since, at least, 1980s. Interpreted as new type Kelvin wave, this disruption associated dramatic changes clouds’ opacity and distribution aerosols, it may constitute critical piece for our understanding thermal balance atmospheric circulation Venus. Here, we report its reappearance on dayside middle clouds four years after last detection with Akatsuki/IR1, first time, characterize main properties using exclusively near-infrared amateur observations. In agreement previous reports, exhibited temporal variations zonal speed, orientation, length, effect over albedo during 2019/2020 eastern elongation. Finally, comparison simultaneous observations by Akatsuki UVI LIR confirmed that not visible upper or emission, while speeds are slower than winds top faster clouds, evidencing wave might transporting momentum up clouds.