Depth Dependent Dynamics Explain the Equatorial Jet Difference Between Jupiter and Saturn

Fuente: arXiv
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Main Authors: Duer, Keren, Galanti, Eli, Kaspi, Yohai
Format: Preprint
Published: 2024
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author Duer, Keren
Galanti, Eli
Kaspi, Yohai
author_facet Duer, Keren
Galanti, Eli
Kaspi, Yohai
contents Jupiter's equatorial eastward zonal flows reach wind velocities of ~100 m/s, while on Saturn they are three times as strong and extend about twice as wide in latitude, despite the two planets being overall dynamically similar. Recent gravity measurements obtained by the Juno and Cassini spacecraft uncovered that the depth of zonal flows on Saturn is about three times greater than on Jupiter. Here we show, using 3D deep convection simulations, that the atmospheric depth is the determining factor controlling both the strength and latitudinal extent of the equatorial zonal flows, consistent with the measurements for both planets. We show that the atmospheric depth is proportional to the convectively driven eddy momentum flux, which controls the strength of the zonal flows. These results provide a mechanistic explanation for the observed differences in the equatorial regions of Jupiter and Saturn, and offer new understandings about the dynamics of gas giants beyond the Solar System.
format Preprint
id arxiv_https___arxiv_org_abs_2410_21929
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Depth Dependent Dynamics Explain the Equatorial Jet Difference Between Jupiter and Saturn
Duer, Keren
Galanti, Eli
Kaspi, Yohai
Earth and Planetary Astrophysics
Jupiter's equatorial eastward zonal flows reach wind velocities of ~100 m/s, while on Saturn they are three times as strong and extend about twice as wide in latitude, despite the two planets being overall dynamically similar. Recent gravity measurements obtained by the Juno and Cassini spacecraft uncovered that the depth of zonal flows on Saturn is about three times greater than on Jupiter. Here we show, using 3D deep convection simulations, that the atmospheric depth is the determining factor controlling both the strength and latitudinal extent of the equatorial zonal flows, consistent with the measurements for both planets. We show that the atmospheric depth is proportional to the convectively driven eddy momentum flux, which controls the strength of the zonal flows. These results provide a mechanistic explanation for the observed differences in the equatorial regions of Jupiter and Saturn, and offer new understandings about the dynamics of gas giants beyond the Solar System.
title Depth Dependent Dynamics Explain the Equatorial Jet Difference Between Jupiter and Saturn
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2410.21929