Stability of the Jupiter Southern Polar Vortices Inspected Through Vorticity Using Juno/JIRAM Data. Issue 8 (5th August 2022)

• Record Type: Journal Article
• Authors: Scarica, P.; Grassi, D.; Mura, A.; Adriani, A.; Ingersoll, A.; Li, C.; Piccioni, G.; Sindoni, G.; Moriconi, M. L.; Plainaki, C.; Altieri, F.; Cicchetti, A.; Dinelli, B. M.; Filacchione, G.; Migliorini, A.; Noschese, R.; Sordini, R.; Stefani, S.; Tosi, F.; Turrini, D.
• Is Part Of: Journal of geophysical research. Volume 127:Issue 8(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-05
• Subjects: Jupiter -- planetary atmospheres -- polar regions; Planets -- Periodicals; Geophysics -- Periodicals; 559.9
• DOI: 10.1029/2021JE007159
• Languages: English
• ISSNs: 2169-9097

Abstract

Abstract: The Jovian InfraRed Auroral Mapper (JIRAM) onboard the NASA Juno mission monitored the evolution of Jupiter's polar cyclones since their first observation ever in February 2017. Data acquired by JIRAM have revealed cloudy cyclones organized in a complex, yet stable geometrical pattern at both poles. Several studies have investigated the dynamics and the structure of these cyclones, to understand the physical mechanisms behind their formation and evolution. In this work, we present vorticity maps deduced from the wind fields for the region poleward of ∼−80°, which has been extensively covered over the last four years of observations. The cyclonic features related to the stable polar cyclones are embedded in a slightly, but diffused anticyclonic circulation, in which short‐living anticyclones emerge with respect to the surroundings. Although the general stability of both the cyclones and the whole system is strongly confirmed by this work, variations in the shape of the vortices, as well as changes in the local structures, have been observed. Plain Language Summary: The Jovian InfraRed Auroral Mapper is the instrument onboard the NASA Juno spacecraft that has provided observations of Jupiter's poles since February 2017. These data have shown cyclones organized in snowflake‐like structures. The Jupiter's polar cyclones are long‐lasting features, which did not disappear or merge during 4 years of observations. In general, the analysis of the winds is important in the study of the cyclones. In this work, we focus on the vorticity, a quantity derived by the winds, that gives information on the magnitude and direction of the rotation of the cyclones. We focused on the southern polar region, which has a better coverage in time, with respect to the northern counterpart. The general pattern of the southern polar cyclones is preserved along the observations. Key Points: The vorticity field of Jupiter's southern polar cyclones is evaluated for different orbits The temporal variability of the vorticity field of the central polar cyclone is analyzed We found extremely long stability of the morphology of circumpolar cyclones both in terms of clouds and winds