University of Leicester
Browse

JWST observations of exogenic species on Jupiter: HCN, H2O, and CO2

Download (2.75 MB)
journal contribution
posted on 2025-05-06, 15:11 authored by Pablo Rodríguez-Ovalle, Thierry Fouchet, Thibault Cavalié, Emmanuel Lellouch, Leigh FletcherLeigh Fletcher, Jake Harkett, Vincent Hue, Bilal Benmahi, Imke de Pater
Context. The impact of the Shoemaker-Levy 9 (SL9) comet on Jupiter in 1994 opened up a new field of study focused on the exogenic species within Jupiter’s atmosphere. Among these species, we find H2O, CO, and HCN. It is thought that these species coexist at the same pressure level (∼3 mbar in 2022) and that the interaction between some of them creates daughter molecules such as CO2. However, understanding their complex meridional distributions is still a matter of debate. Aims. We measured the meridional distribution of H2O, HCN, and CO2 to understand the chemistry and dynamics leading to these distributions. Methods. We used James Webb Space Telescope (JWST) Mid InfraRed Instrument (MIRI) medium-resolution spectroscopy observations from 17∘S to 26∘S, and from 45∘S towards the south pole for CO2, H2O, and HCN. We used a radiative transfer code coupled with an inversion algorithm to retrieve the temperature using the CH4 v4 band and the abundance of the species for the different latitudes. Results. We found an increase in H2O in the south polar region, while CO2 is found to be depleted, which points towards an exchange of oxygen between H2O and CO2 happening in the southern auroral region. The HCN abundance decreases towards the pole, and abundance values are similar to the ones obtained with ALMA in 2017. The depletion of HCN may be due to heterogeneous chemistry related to stratospheric polar aerosols. Conclusions. The exogenic molecules analysed seem to be influenced either by polar aerosols produced by ion-neutral chemistry (e.g. HCN) or by particle precipitation occurring in the auroral regions (e.g. H2O and CO2). These measurements provide new insights into chemical evolution at a small spatial scale, revealing previously undetected localized trends.

History

Author affiliation

College of Science & Engineering Physics & Astronomy

Version

  • VoR (Version of Record)

Published in

Astronomy & Astrophysics

Volume

696

Pagination

A173 - A173

Publisher

EDP Sciences

issn

0004-6361

eissn

1432-0746

Copyright date

2025

Available date

2025-05-06

Language

en

Deposited by

Professor Leigh Fletcher

Deposit date

2025-04-23

Data Access Statement

Level-3 calibrated Jupiter MIRI/MRS data from the standard pipeline are publicly available through the MAST archive at https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html (MISSION: JWST, PROPOSAL-ID: 1373). The radiative transfer and retrieval code utilized in this work, as well as in previous studies (Fouchet et al. 2016; Guerlet et al. 2009), is available for download at Rodriguez-Ovalle (2024). The JWST calibration pipeline used in this study (version 1.11.3) can be accessed via Bushouse et al. (2022). The data products generated in this study are available at Rodríguez-Ovalle & Fouchet (2025).