A Preliminary Jupiter Model

TL;DR

This paper develops preliminary models of Jupiter's interior using ab initio simulations and gravity calculations, predicting gravitational harmonics and core properties in anticipation of Juno data.

Contribution

It introduces a self-consistent Jupiter interior model combining ab initio simulations with a new gravity calculation method, accounting for helium rain effects.

Findings

Predicted zonal harmonic values for Jupiter's gravity field.

A dense core of about 12 Earth masses.

Envelope metallicity approximately three times solar.

Abstract

In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen-helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses, and a hydrogen-helium-rich envelope with approximately 3 times solar metallicity.