Coupled 1D Chemical Kinetic-Transport and 2D Hydrodynamic Modeling Supports a modest 1-1.5x Supersolar Oxygen Abundance in Jupiter's Atmosphere

TL;DR

This study combines 1D chemical kinetics and 2D hydrodynamics to estimate Jupiter's deep oxygen abundance, suggesting a modest supersolar enrichment, and introduces a method to determine eddy diffusion coefficients relevant to planetary atmospheres.

Contribution

It presents a novel coupled modeling approach integrating thermochemical kinetics with hydrodynamics to constrain Jupiter's oxygen levels and derive eddy diffusion coefficients, applicable to exoplanet atmospheres.

Findings

Jupiter's oxygen abundance is 1.0-1.5 times solar.

Derived eddy diffusion coefficient Kzz is 3e6 to 5e7 cm^2/s.

Jupiter's C/O ratio is approximately 2.9.

Abstract

Understanding the deep atmospheric composition of Jupiter provides critical constraints on its formation and the chemical evolution of the solar nebula. In this study, we combine one-dimensional thermochemical kinetic-transport modeling with two-dimensional hydrodynamic simulations to constrain Jupiter's deep oxygen abundance using carbon monoxide (CO) as a proxy tracer. Leveraging a comprehensive chemical network generated by Reaction Mechanism Generator (RMG), we assess the impact of updated reaction rates, including the often-neglected but thermochemically significant Hidaka reaction (CH3OH + H -> CH3 + H2O). Our 1D-2D coupled approach supports a modest supersolar oxygen enrichment of 1.0-1.5x the solar value. We also present a method for deriving Jupiter's eddy diffusion coefficient Kzz = 3e6 to 5e7 cm2/s) from 2D hydrodynamic simulations using the quasi steady-state approach. This method is applicable to exoplanet atmospheres, where Kzz remains highly uncertain despite its strong influence on atmospheric chemistry. Finally, our results imply a significantly elevated planetary carbon-to-oxygen (C/O) ratio of ~2.9, highlighting the importance of clarifying the mechanisms behind the preferential accretion of carbon-rich material during Jupiter's formation. By integrating thermochemical and hydrodynamic processes, our study offers a more complete framework for constraining chemical and dynamical processes in (exo)planetary atmospheres.