Explaining Jupiter's magnetic field and equatorial jet dynamics

TL;DR

This paper presents a numerical dynamo model that successfully replicates Jupiter's magnetic field and equatorial jet dynamics by incorporating recent interior models, predicting observable magnetic features and secular variations.

Contribution

It introduces the first dynamo simulation that aligns with Jupiter's observed magnetic field structure and strength using advanced interior models.

Findings

Model reproduces Jupiter's magnetic field structure and strength.

Predicts observable banded magnetic features related to the equatorial jet.

Estimates secular variation of about 2000 nT per year.

Abstract

Spacecraft data reveal a very Earth-like Jovian magnetic field. This is surprising since numerical simulations have shown that the vastly different interiors of terrestrial and gas planets can strongly affect the internal dynamo process. Here we present the first numerical dynamo that manages to match the structure and strength of the observed magnetic field by embracing the newest models for Jupiter's interior. Simulated dynamo action primarily occurs in the deep high electrical conductivity region while zonal flows are dynamically constrained to a strong equatorial jet in the outer envelope of low conductivity. Our model reproduces the structure and strength of the observed global magnetic field and predicts that secondary dynamo action associated to the equatorial jet produces banded magnetic features likely observable by the Juno mission. Secular variation in our model scales to about 2000 nT per year and should also be observable during the one year nominal mission duration.