Presentation #409.04 in the session “Giant Planets: Simulations”.
The Jovian atmosphere hosts a dynamic range of phenomena that are dependent on latitude. The lower latitudes are dominated by large-scale jet streams pinched between belts and zones, long-lived storms such as the Great Red Spot, and ever-evolving planetary waves, making the environment a unique laboratory for observers and modelers alike. However, beyond ±60˚ Jupiter exhibits stark morphological contrast in its dynamics. The large-scale banded structure undergoes turbulent self-organization into discretized vortices. Most strikingly, both hemispheres host vortices in distinct polygonal configurations, revealed for the first time by the Juno mission. Efforts to model the polar regions of Jupiter have been limited due to the polar singularity, and prohibitive computational resources. Recently, 3D models captured the emergence and evolution of polar vortex configurations. However, quasi-2D shallow water modeling may further illuminate the mechanisms involved in the development of underlying instabilities that lead to such structures.
In our work, we use the Pencil Code, a finite-difference, high-order, modular and versatile code. The code has been used in studies of the sun and the solar nebula, and is used here for the study of planetary atmospheres for the first time via the shallow water approximation. We explore the overall dynamics and evolution of the Jovian poles by employing a systematic study of the deformation length (Ld), storm perturbation parameters, and underlying geopotential. We find that flows with low Ld are only marginally stable to perturbations at the polar regions, while flows with large Ld are stable with respect to Arnol’d’s instability theorem over the same timescale. Thus, lower Ld models exhibit higher morphological variation, in general. Furthermore, high Ld models with large perturbation size for the storms result in less coherent vortex formations and resemble the Folded Filamentary Regions seen in Juno images. Our findings support the results of previous works regarding the effect of the Burger number on planetary atmospheres, and introduces a diverse hydrodynamic code to the atmospheres modeling community.