Oscillations and Stability of the Jupiter Polar Cyclones. Issue 14 (23rd July 2021)

• Record Type: Journal Article
• Authors: Mura, A.; Adriani, A.; Bracco, A.; Moriconi, M. L.; Grassi, D.; Plainaki, C.; Ingersoll, A.; Bolton, S.; Sordini, R.; Altieri, F.; Ciarravano, A.; Cicchetti, A.; Dinelli, B. M.; Filacchione, G.; Migliorini, A.; Noschese, R.; Piccioni, G.; Scarica, P.; Sindoni, G.; Stefani, S.; Tosi, F.; Turrini, D.
• Is Part Of: Geophysical research letters. Volume 48:Issue 14(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-07-23
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2021GL094235
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Juno discovered the circumpolar cyclones polygons on Jupiter in 2017. Fundamental questions regarding Jovian cyclogenesis concern the formation mechanism and whether these cyclones are deep or shallow. Recent data by Juno/JIRAM infrared camera show that any change is an extremely unlikely event on an annual scale. Only once, in 2019, a sixth cyclone joined the pentagonal structure in the South, but it disappeared after 2 months without merging with the pre‐existing cyclones; disappearance or creation of stable cyclones has never been observed. Additionally, the rotation speeds of the north and south polygons as a whole are not compatible with the shallow hypothesis; both structures drift at a much smaller rate than the typical scale velocities on Jupiter surface, and differ at the two poles. Cyclones oscillate around what may seem like equilibrium positions, and these oscillations tend to propagate from one cyclone to another. These oscillations have almost equal timescales, and here we investigate the possible implications of such similarity. Plain Language Summary: Juno/JIRAM performed four year of observations of the circumpolar structures at Jupiter. We investigate three major properties of these structures: they spin slowly, but at different rates, the South one being twice as fast as the North one; both structures as a whole, and the 15 singular cyclones are extremely stable; the cyclones have similar intrinsic oscillation frequencies, and perturbations seem to propagate from one cyclone to the closer one. Key Points: Juno performed 4 years of observations of the Jupiter polar cyclones. We discuss implications for their stability and vertical structure The cyclones have similar intrinsic oscillation frequencies, and perturbations seem to propagate from one cyclone to the closer one Cyclones are extremely stable, individually and as a whole; they slowly spin and the South one is twice as fast as the North one