Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxides
Abstract Radiative cooling by molecules is a crucial process for hydrodynamic escape, as it can efficiently remove the thermal energy driving the outflow, acquired through X-ray and extreme UV absorption. Carbon oxides, such as CO and CO2, and their photochemical products are anticipated to serve as...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2024-11-01
|
| Series: | Progress in Earth and Planetary Science |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s40645-024-00666-3 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850163091685244928 |
|---|---|
| author | Tatsuya Yoshida Naoki Terada Kiyoshi Kuramoto |
| author_facet | Tatsuya Yoshida Naoki Terada Kiyoshi Kuramoto |
| author_sort | Tatsuya Yoshida |
| collection | DOAJ |
| description | Abstract Radiative cooling by molecules is a crucial process for hydrodynamic escape, as it can efficiently remove the thermal energy driving the outflow, acquired through X-ray and extreme UV absorption. Carbon oxides, such as CO and CO2, and their photochemical products are anticipated to serve as vital radiative cooling sources not only in atmospheres dominated by carbon oxides but also in H2-rich atmospheres. However, their specific effects on the hydrodynamic escape, especially in H2-rich atmospheres, have been inadequately investigated. In this study, we conduct 1-D hydrodynamic escape simulations for H2-rich atmospheres incorporating CO, CO2, and their chemical products on an Earth-mass planet. We consider detailed radiative cooling processes and chemical networks related to carbon oxides to elucidate their impacts on the hydrodynamic escape. In the escape outflow, CO2 undergoes rapid photolysis, producing CO and atomic oxygen, while CO exhibits photochemical stability compared to CO2. The H2 oxidation by atomic oxygen results in the production of OH and H2O. Consequently, the hydrodynamic escape is significantly suppressed by the radiative cooling effects of CO, H2O, OH, and H3 + even when the basal mixing fraction of CO and CO2 is lower than ~ 0.01. These mechanisms extend the lifetime of H2-rich atmospheres by about one order of magnitude compared to the case of pure hydrogen atmospheres on early Earth, which also results in negligible escape of heavier carbon- and nitrogen-bearing molecules and noble gases. |
| format | Article |
| id | doaj-art-6381e06012274aeb9ed20a00bddbbc9f |
| institution | OA Journals |
| issn | 2197-4284 |
| language | English |
| publishDate | 2024-11-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Progress in Earth and Planetary Science |
| spelling | doaj-art-6381e06012274aeb9ed20a00bddbbc9f2025-08-20T02:22:21ZengSpringerOpenProgress in Earth and Planetary Science2197-42842024-11-0111111310.1186/s40645-024-00666-3Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxidesTatsuya Yoshida0Naoki Terada1Kiyoshi Kuramoto2Graduate School of Science, Tohoku UniversityGraduate School of Science, Tohoku UniversityFaculty of Science, Hokkaido UniversityAbstract Radiative cooling by molecules is a crucial process for hydrodynamic escape, as it can efficiently remove the thermal energy driving the outflow, acquired through X-ray and extreme UV absorption. Carbon oxides, such as CO and CO2, and their photochemical products are anticipated to serve as vital radiative cooling sources not only in atmospheres dominated by carbon oxides but also in H2-rich atmospheres. However, their specific effects on the hydrodynamic escape, especially in H2-rich atmospheres, have been inadequately investigated. In this study, we conduct 1-D hydrodynamic escape simulations for H2-rich atmospheres incorporating CO, CO2, and their chemical products on an Earth-mass planet. We consider detailed radiative cooling processes and chemical networks related to carbon oxides to elucidate their impacts on the hydrodynamic escape. In the escape outflow, CO2 undergoes rapid photolysis, producing CO and atomic oxygen, while CO exhibits photochemical stability compared to CO2. The H2 oxidation by atomic oxygen results in the production of OH and H2O. Consequently, the hydrodynamic escape is significantly suppressed by the radiative cooling effects of CO, H2O, OH, and H3 + even when the basal mixing fraction of CO and CO2 is lower than ~ 0.01. These mechanisms extend the lifetime of H2-rich atmospheres by about one order of magnitude compared to the case of pure hydrogen atmospheres on early Earth, which also results in negligible escape of heavier carbon- and nitrogen-bearing molecules and noble gases.https://doi.org/10.1186/s40645-024-00666-3Hydrodynamic escapeH2-rich atmosphereCarbon oxidesRadiative coolingPhotochemistryEarly Earth |
| spellingShingle | Tatsuya Yoshida Naoki Terada Kiyoshi Kuramoto Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxides Progress in Earth and Planetary Science Hydrodynamic escape H2-rich atmosphere Carbon oxides Radiative cooling Photochemistry Early Earth |
| title | Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxides |
| title_full | Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxides |
| title_fullStr | Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxides |
| title_full_unstemmed | Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxides |
| title_short | Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxides |
| title_sort | suppression of hydrodynamic escape of an h2 rich early earth atmosphere by radiative cooling of carbon oxides |
| topic | Hydrodynamic escape H2-rich atmosphere Carbon oxides Radiative cooling Photochemistry Early Earth |
| url | https://doi.org/10.1186/s40645-024-00666-3 |
| work_keys_str_mv | AT tatsuyayoshida suppressionofhydrodynamicescapeofanh2richearlyearthatmospherebyradiativecoolingofcarbonoxides AT naokiterada suppressionofhydrodynamicescapeofanh2richearlyearthatmospherebyradiativecoolingofcarbonoxides AT kiyoshikuramoto suppressionofhydrodynamicescapeofanh2richearlyearthatmospherebyradiativecoolingofcarbonoxides |