Fletcher, Leigh N.Leigh N.FletcherMelin, H.H.MelinADRIANI, AlbertoAlbertoADRIANISimon, A. A.A. A.SimonSanchez-Lavega, A.A.Sanchez-LavegaDonnelly, P. T.P. T.DonnellyAntuñano, A.A.AntuñanoOrton, G. S.G. S.OrtonHueso, R.R.HuesoKraaikamp, E.E.KraaikampWong, M. H.M. H.WongBarnett, M.M.BarnettMoriconi, M. L.M. L.MoriconiALTIERI, FRANCESCAFRANCESCAALTIERISindoni, G.G.Sindoni2021-02-242021-02-2420180004-6256http://hdl.handle.net/20.500.12386/30590We characterize the origin and evolution of a mesoscale wave pattern in Jupiter’s North Equatorial Belt (NEB), detected for the first time at 5 μm using a 2016-17 campaign of “lucky imaging” from the VISIR instrument on the Very Large Telescope and the NIRI instrument on the Gemini observatory, coupled with M-band imaging from Juno’s JIRAM instrument during the first seven Juno orbits. The wave is compact, with a 1.°1-1.°4 longitude wavelength (wavelength 1300-1600 km, wavenumber 260-330) that is stable over time, with wave crests aligned largely north-south between 14°N and 17°N (planetographic). The waves were initially identified in small (10° longitude) packets immediately west of cyclones in the NEB at 16°N but extended to span wider longitude ranges over time. The waves exhibit a 7-10 K brightness temperature amplitude on top of an ∼210 K background at 5 μm. The thermal structure of the NEB allows for both inertio-gravity waves and gravity waves. Despite detection at 5 μm, this does not necessarily imply a deep location for the waves, and an upper tropospheric aerosol layer near 400-800 mbar could feature a gravity wave pattern modulating the visible-light reflectivity and attenuating the 5-μm radiance originating from deeper levels. Strong rifting activity appears to obliterate the pattern, which can change on timescales of weeks. The NEB underwent a new expansion and contraction episode in 2016-17 with associated cyclone-anticyclone formation, which could explain why the mesoscale wave pattern was more vivid in 2017 than ever before.STAMPAenArticle10.3847/1538-3881/aace022-s2.0-85051470100000439835300002https://iopscience.iop.org/article/10.3847/1538-3881/aace022018AJ....156...67FFIS/05 - ASTRONOMIA E ASTROFISICA