Jupiter's evolution with primordial composition gradients

TL;DR

This study models Jupiter's evolution considering primordial composition gradients, revealing that a significant portion of the planet's interior may remain non-adiabatic, affecting its bulk composition understanding.

Contribution

It introduces a Jupiter evolution model with a primordial heavy-element gradient, highlighting the persistence of non-adiabatic regions in the interior.

Findings

Outer envelope becomes adiabatic within 10^7 years

Deep interior retains composition gradients and higher temperatures

Layered convection potential limited to about 10% of Jupiter's mass

Abstract

Recent formation and structure models of Jupiter suggest that the planet can have composition gradients and not be fully convective (adiabatic). This possibility directly affects our understanding of Jupiter's bulk composition and origin. In this Letter we present Jupiter's evolution with a primordial structure consisting of a relatively steep heavy-element gradient of 40 Earth masses. We show that for a primordial structure with composition gradients, most of the mixing occurs in the outer part of the gradient during the early evolution (several 10^7 years), leading to an adiabatic outer envelope (60% of Jupiter's mass). We find that the composition gradient in the deep interior persists, suggesting that about 40% of Jupiter's mass can be non-adiabatic with a higher temperature than the one derived from Jupiter's atmospheric properties. The region that can potentially develop layered-convection in Jupiter today is estimated to be limited to about 10% of the mass.