# A new chemical scheme for giant planet thermochemistry. Update of the methanol chemistry and new reduced chemical scheme

Source: [A new chemical scheme for giant planet thermochemistry. Update of the methanol chemistry and new reduced chemical scheme](<https://www.sota2.com/research/paper/68fa3b801e209131ce8d3304>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-25T00:37:52.438Z

Authors: Olivia Venot, Thibault Cavali\\'e, Roda Bounaceur, Pascal Tremblin, Lothaire Brouillard, Romain Lhoussaine Ben Brahim

Published: 2019-12-16T08:39:56.000Z

## Abstract

Several chemical networks have been developed to study warm (exo)planetary atmospheres. The kinetics of the reactions related to the methanol chemistry included in these schemes have been questioned. The goal of this paper is to update the methanol chemistry for such chemical networks thanks to recent publications in the combustion literature. We aim also at studying the consequences of this update on the atmospheric compositions of (exo)planetary atmospheres and brown dwarfs. We have performed an extensive review of combustion experimental studies and revisited the sub-mechanism describing methanol combustion in the scheme of Venot et al. (2012, A&A 624, A58). The updated scheme involves 108 species linked by a total of 1906 reactions. We have then applied our 1D kinetic model with this new scheme to several case studies (HD 209458b, HD 189733b, GJ 436b, GJ 1214b, ULAS J1335+11, Uranus, Neptune), and compared the results obtained with those obtained with the former scheme. The update of the scheme has a negligible impact on hot Jupiters atmospheres. However, the atmospheric composition of warm Neptunes and brown dwarfs is modified sufficiently to impact observational spectra in the wavelength range JWST will operate. Concerning Uranus and Neptune, the update of the chemical scheme modifies the abundance of CO and thus impacts the deep oxygen abundance required to reproduce the observational data. For future 3D kinetics models, we also derived a reduced scheme containing 44 species and 582 reactions. Chemical schemes should be regularly updated in order to maintain a high level of reliability on the results of kinetic models and be able to improve our knowledge on planetary formation.

## Recorded benchmark results

A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage.

## Original sources and implementation

[Original paper](<https://arxiv.org/abs/1912.07246>)

[PDF](<https://arxiv.org/pdf/1912.07246.pdf>)