Global chemical transport on hot Jupiters: Insights from the 2D VULCAN photochemical model
| dc.contributor.author | Tsai, Shang-Min | |
| dc.contributor.author | Parmentier, Vivien | |
| dc.contributor.author | Mendonça, João M. | |
| dc.contributor.author | Tan, Xianyu | |
| dc.contributor.author | Deitrick, Russell | |
| dc.contributor.author | Hammond, Mark | |
| dc.contributor.author | Savel, Arjun | |
| dc.contributor.author | Zhang, Xi | |
| dc.contributor.author | Pierrehumbert, Raymond | |
| dc.contributor.author | Schwieterman, Edward | |
| dc.date.accessioned | 2024-07-08T15:27:06Z | |
| dc.date.available | 2024-07-08T15:27:06Z | |
| dc.date.issued | 2024 | |
| dc.description.abstract | The atmospheric dynamics of tidally locked hot Jupiters is characterized by strong equatorial winds. Understanding the interaction between global circulation and chemistry is crucial in atmospheric studies and interpreting observations. Two-dimensional (2D) photochemical transport models shed light on how the atmospheric composition depends on circulation. In this paper, we introduce the 2D photochemical (horizontal and vertical) transport model, VULCAN 2D, which improves on the pseudo-2D approaches by allowing for nonuniform zonal winds. We extensively validate our VULCAN 2D with analytical solutions and benchmark comparisons. Applications to HD 189733 b and HD 209458 b reveal a transition in mixing regimes: horizontal transport predominates below ∼0.1 mbar, while vertical mixing is more important at higher altitudes above 0.1 mbar. Motivated by the previously inferred carbon-rich atmosphere, we find that HD 209458 b with supersolar carbon-to-oxygen ratio (C/O) exhibits pronounced C2H4 absorption on the morning limb but not on the evening limb, due to horizontal transport from the nightside. We discuss when a pseudo-2D approach is a valid assumption and its inherent limitations. Finally, we demonstrate the effect of horizontal transport in transmission observations and its impact on the morning−evening limb asymmetry with synthetic spectra, highlighting the need to consider global transport when interpreting exoplanet atmospheres. | |
| dc.description.reviewstatus | Reviewed | |
| dc.description.scholarlevel | Faculty | |
| dc.description.sponsorship | Part of this work is supported by the European community through the ERC advanced grant EXOCONDENSE (No. 740963; PI: R. T. Pierrehumbert). S.-M.T. acknowledges support from NASA Exobiology grant No. 80NSSC20K1437 and the University of California, Riverside. X.Z. acknowledges support from the NASA Exoplanet Research grant 80NSSC22K0236 and the NASA Interdisciplinary Consortia for Astrobiology Research (ICAR) grant 80NSSC21K0597. Financial support to R.D. was provided by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant to C. Goldblatt. | |
| dc.identifier.citation | Tsai, S., Parmentier, V., Mendonça, J. M., Tan, X., Deitrick, R., Hammond, M., Savel, A. B., Zhang, X., Pierrehumbert, R. T., & Schwieterman, E. W. (2024). Global chemical transport on hot Jupiters: Insights from the 2D VULCAN photochemical model. The Astrophysical Journal, 963(1), 41. https://doi.org/10.3847/1538-4357/ad1600 | |
| dc.identifier.uri | https://doi.org/10.3847/1538-4357/ad1600 | |
| dc.identifier.uri | https://hdl.handle.net/1828/16727 | |
| dc.language.iso | en | |
| dc.publisher | The Astrophysical Journal | |
| dc.rights | Attribution 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | |
| dc.subject.department | School of Earth and Ocean Sciences | |
| dc.title | Global chemical transport on hot Jupiters: Insights from the 2D VULCAN photochemical model | |
| dc.type | Article |