image: On its 20th flyby to Jupiter, the JIRAM instrument onboard the Juno spacecraft found a seventh vortex (5 o'clock direction) trying to join the original family of six vortices. But it failed to make it. The later flybys didn't observe the seventh one again view more
Credit: Image credit: Alessandro Mura (National Institute for Astrophysics, Rome, Italy).
A study examines how systems of vortices organized in polygons at the poles of Jupiter remain stable over time. The Juno spacecraft has observed patterns of stable vortices organized in polygons at each pole of Jupiter, with eight and five cyclonic vortices around a central vortex at the north and south poles, respectively. The factors influencing the stability of the cyclones, which have been stable since August 2016, are unknown. Cheng Li and colleagues constructed a numerical model to recreate the vortices and identify factors that influence their behavior. Key to the cyclonic vortices' stability are the depths of the vortices and rings of anticyclonic rotation around each vortex called shielding. Cyclones on Jupiter tend to move poleward, as they do on Earth. If the shielding is insufficient, however, the cyclones merge. Too much shielding can also disrupt the polygonal vortex pattern and drive the vortices apart. The characteristics of Jupiter's polar vortices fall in between the extremes, allowing stability. According to the authors, further research is needed to uncover why the vortices formed and why such a polygonal pattern persists with observed stability on Jupiter but not on other large gas giants, such as Saturn, which exhibits single polar vortices.
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Article #20-08440: "Modeling the stability of polygonal patterns of vortices at the poles of Jupiter as revealed by the Juno spacecraft," by Cheng Li, Andrew P. Ingersoll, Alexandra P. Klipfel, and Harriet Brettle.
MEDIA CONTACT: Cheng Li, University of California, Berkeley, CA; e-mail: <cheng.cli@berkeley.edu>
Journal
Proceedings of the National Academy of Sciences