Day–Night Transport-induced Chemistry and Clouds on WASP-39b: Gas-phase Composition
JWST has recently detected the first robust photochemical product on an exoplanet: sulfur dioxide (SO _2 ) on WASP-39b. The data from the NIRISS instrument also reveal signs of partial coverage of clouds. Most of the previous studies have focused on interpreting spectral data with 1D models. To expl...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2023-01-01
|
| Series: | The Astrophysical Journal Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/2041-8213/ad1405 |
| _version_ | 1797194202453377024 |
|---|---|
| author | Shang-Min Tsai Julianne I. Moses Diana Powell Elspeth K. H. Lee |
| author_facet | Shang-Min Tsai Julianne I. Moses Diana Powell Elspeth K. H. Lee |
| author_sort | Shang-Min Tsai |
| collection | DOAJ |
| description | JWST has recently detected the first robust photochemical product on an exoplanet: sulfur dioxide (SO _2 ) on WASP-39b. The data from the NIRISS instrument also reveal signs of partial coverage of clouds. Most of the previous studies have focused on interpreting spectral data with 1D models. To explore how the chemical species and cloud particles are altered by global circulation, we applied a 2D photochemical model and a 2D microphysical cloud model separately to postprocess the thermal and dynamical structures simulated by a 3D general circulation model of WASP-39b. We found that SO _2 produced by photochemistry on the dayside can be transported to the nightside owing to the efficient replenishment of horizontal transport. The morning–evening limb differences in methane (CH _4 ) abundances predicted by the 1D models disappeared after horizontal transport is included. Similarly, the inclusion of horizontal transport also reduced the limb differences in SO _2 . Our modeling results suggest that the fast zonal wind results in minimal or negligible limb asymmetry in composition. Based on the synthetic spectra generated by our 2D atmosphere simulations, we propose that observing SO _2 absorption in the emission spectra of WASP-39b at different phases may offer opportunities to probe the horizontal quenching process of photochemical products. We will focus on the gas-phase chemistry in this paper and leave the results regarding clouds in the subsequent paper as part of the series. |
| first_indexed | 2024-03-08T19:11:51Z |
| format | Article |
| id | doaj.art-a2f720308fcf49b5aed4b7ba2a3f8356 |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-04-24T05:52:32Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-a2f720308fcf49b5aed4b7ba2a3f83562024-04-23T11:07:11ZengIOP PublishingThe Astrophysical Journal Letters2041-82052023-01-019592L3010.3847/2041-8213/ad1405Day–Night Transport-induced Chemistry and Clouds on WASP-39b: Gas-phase CompositionShang-Min Tsai0https://orcid.org/0000-0002-8163-4608Julianne I. Moses1https://orcid.org/0000-0002-8837-0035Diana Powell2https://orcid.org/0000-0002-4250-0957Elspeth K. H. Lee3https://orcid.org/0000-0002-3052-7116Department of Earth and Planetary Sciences, University of California , Riverside, CA, USASpace Science Institute , Boulder, CO, USACenter for Astrophysics ∣ Harvard & Smithsonian , Cambridge, USA; Department of Astronomy & Astrophysics, University of Chicago , Chicago, IL, USACenter for Space and Habitability, University of Bern , Gesellschaftsstrasse 6, CH-3012 Bern, SwitzerlandJWST has recently detected the first robust photochemical product on an exoplanet: sulfur dioxide (SO _2 ) on WASP-39b. The data from the NIRISS instrument also reveal signs of partial coverage of clouds. Most of the previous studies have focused on interpreting spectral data with 1D models. To explore how the chemical species and cloud particles are altered by global circulation, we applied a 2D photochemical model and a 2D microphysical cloud model separately to postprocess the thermal and dynamical structures simulated by a 3D general circulation model of WASP-39b. We found that SO _2 produced by photochemistry on the dayside can be transported to the nightside owing to the efficient replenishment of horizontal transport. The morning–evening limb differences in methane (CH _4 ) abundances predicted by the 1D models disappeared after horizontal transport is included. Similarly, the inclusion of horizontal transport also reduced the limb differences in SO _2 . Our modeling results suggest that the fast zonal wind results in minimal or negligible limb asymmetry in composition. Based on the synthetic spectra generated by our 2D atmosphere simulations, we propose that observing SO _2 absorption in the emission spectra of WASP-39b at different phases may offer opportunities to probe the horizontal quenching process of photochemical products. We will focus on the gas-phase chemistry in this paper and leave the results regarding clouds in the subsequent paper as part of the series.https://doi.org/10.3847/2041-8213/ad1405Exoplanet atmospheresExoplanet atmospheric compositionExtrasolar gaseous planets |
| spellingShingle | Shang-Min Tsai Julianne I. Moses Diana Powell Elspeth K. H. Lee Day–Night Transport-induced Chemistry and Clouds on WASP-39b: Gas-phase Composition The Astrophysical Journal Letters Exoplanet atmospheres Exoplanet atmospheric composition Extrasolar gaseous planets |
| title | Day–Night Transport-induced Chemistry and Clouds on WASP-39b: Gas-phase Composition |
| title_full | Day–Night Transport-induced Chemistry and Clouds on WASP-39b: Gas-phase Composition |
| title_fullStr | Day–Night Transport-induced Chemistry and Clouds on WASP-39b: Gas-phase Composition |
| title_full_unstemmed | Day–Night Transport-induced Chemistry and Clouds on WASP-39b: Gas-phase Composition |
| title_short | Day–Night Transport-induced Chemistry and Clouds on WASP-39b: Gas-phase Composition |
| title_sort | day night transport induced chemistry and clouds on wasp 39b gas phase composition |
| topic | Exoplanet atmospheres Exoplanet atmospheric composition Extrasolar gaseous planets |
| url | https://doi.org/10.3847/2041-8213/ad1405 |
| work_keys_str_mv | AT shangmintsai daynighttransportinducedchemistryandcloudsonwasp39bgasphasecomposition AT julianneimoses daynighttransportinducedchemistryandcloudsonwasp39bgasphasecomposition AT dianapowell daynighttransportinducedchemistryandcloudsonwasp39bgasphasecomposition AT elspethkhlee daynighttransportinducedchemistryandcloudsonwasp39bgasphasecomposition |