Polar vortex crystals on Jupiter: Simulating Jupiter’s atmosphere using a Quasi-Geostrophic model

Juno spacecraft observed persistent polygonal patterns of large cyclones at both the north and south poles ^[1]. These patterns have been studied by plasma physics, but they are the first of their kind on a planet. Siegelman used a one-layer quasi-geostrophic (QG) model with initial turbulence to study the formation of vortex crystals ^[2]. Li used a one-layer shallow water (SW) model with initial large-scale vortices to demonstrate the importance of vortex shielding ^[3]. Chen et al. used the SW equations starting with initial turbulence to study the vertical structure of the layer. ^[4] However, these simulations all began with an initial disturbance and did not include continuous forcing balanced by dissipation, which is closer to the real situation on Jupiter. We intend to use a QG model at the pole of a rotating planet to study the evolution of vortices under the influence of forcing and dissipation. An important parameter of the models is the radius of deformation ), where g is the gravitational acceleration, h is the thickness of the weather layer,  is the fractional density difference between the weather layer and the deep abyssal layer below, and  is the planetary rotation. To get vortex crystals, the models starting with initial turbulence require large values of , implying stable stratification and a thick weather layer penetrating down into the abyssal layer. Whether this requirement applies when the flow is continuously forced and balanced by dissipation is an important result of this study.

 

 

[1] Adriani, A., A. Mura, G. Orton, et al., Clusters of cyclones encircling Jupiter’s poles. Nature 555, 216–219. https://doi.org/10.1038/nature25491 (2018).

[2] Siegelman, L., W.R. Young, A.P. Ingersoll, Polar vortex crystals: Emergence and structure, Proc. Natl. Acad. Sci. U.S.A. 119 (17) e2120486119, https://doi.org/10.1073/pnas.2120486119(2022).

[3] Li, C., A.P. Ingersoll, A.P. Klipfel, H. Brettle, Modeling the stability of polygonal patterns of vortices at the poles of Jupiter as revealed by the Juno spacecraft, Proc. Natl. Acad. Sci. U.S.A. 117 (39) 24082-24087, https://doi.org/10.1073/pnas.2008440117(2020).

[4] Chen, S., A. P. Ingersoll, and C. Li, Vortex crystals at Jupiter’s poles: Emergence controlled by initial small-scale turbulence. Icarus 429 (2025): 116438.