Atmospheric circulation of hot Jupiters: dayside–nightside temperature differences. II. Comparison with observations
The full-phase infrared light curves of low-eccentricity hot Jupiters show a trend of increasing fractional dayside–nightside brightness temperature difference with increasing incident stellar flux, both averaged across the infrared and in each individual wavelength band. The analytic theory of Koma...
| Main Authors: | , , |
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| Format: | Journal article |
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American Astronomical Society
2017
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| _version_ | 1797062182691667968 |
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| author | Komacek, T Showman, A Tan, X |
| author_facet | Komacek, T Showman, A Tan, X |
| author_sort | Komacek, T |
| collection | OXFORD |
| description | The full-phase infrared light curves of low-eccentricity hot Jupiters show a trend of increasing fractional dayside–nightside brightness temperature difference with increasing incident stellar flux, both averaged across the infrared and in each individual wavelength band. The analytic theory of Komacek & Showman shows that this trend is due to the decreasing ability with increasing incident stellar flux of waves to propagate from day to night and erase temperature differences. Here, we compare the predictions of this theory with observations, showing that it explains well the shape of the trend of increasing dayside–nightside temperature difference with increasing equilibrium temperature. Applied to individual planets, the theory matches well with observations at high equilibrium temperatures but, for a fixed photosphere pressure of $100\ \mathrm{mbar}$, systematically underpredicts the dayside–nightside brightness temperature differences at equilibrium temperatures less than $2000\ {\rm{K}}$. We interpret this as being due to the effects of a process that moves the infrared photospheres of these cooler hot Jupiters to lower pressures. We also utilize general circulation modeling with double-gray radiative transfer to explore how the circulation changes with equilibrium temperature and drag strengths. As expected from our theory, the dayside–nightside temperature differences from our numerical simulations increase with increasing incident stellar flux and drag strengths. We calculate model phase curves using our general circulation models, from which we compare the broadband infrared offset from the substellar point and dayside–nightside brightness temperature differences against observations, finding that strong drag or additional effects (e.g., clouds and/or supersolar metallicities) are necessary to explain many observed phase curves. |
| first_indexed | 2024-03-06T20:41:55Z |
| format | Journal article |
| id | oxford-uuid:34930ec6-a40a-41a0-a665-c3c6dc89658c |
| institution | University of Oxford |
| last_indexed | 2024-03-06T20:41:55Z |
| publishDate | 2017 |
| publisher | American Astronomical Society |
| record_format | dspace |
| spelling | oxford-uuid:34930ec6-a40a-41a0-a665-c3c6dc89658c2022-03-26T13:26:49ZAtmospheric circulation of hot Jupiters: dayside–nightside temperature differences. II. Comparison with observationsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:34930ec6-a40a-41a0-a665-c3c6dc89658cSymplectic Elements at OxfordAmerican Astronomical Society2017Komacek, TShowman, ATan, XThe full-phase infrared light curves of low-eccentricity hot Jupiters show a trend of increasing fractional dayside–nightside brightness temperature difference with increasing incident stellar flux, both averaged across the infrared and in each individual wavelength band. The analytic theory of Komacek & Showman shows that this trend is due to the decreasing ability with increasing incident stellar flux of waves to propagate from day to night and erase temperature differences. Here, we compare the predictions of this theory with observations, showing that it explains well the shape of the trend of increasing dayside–nightside temperature difference with increasing equilibrium temperature. Applied to individual planets, the theory matches well with observations at high equilibrium temperatures but, for a fixed photosphere pressure of $100\ \mathrm{mbar}$, systematically underpredicts the dayside–nightside brightness temperature differences at equilibrium temperatures less than $2000\ {\rm{K}}$. We interpret this as being due to the effects of a process that moves the infrared photospheres of these cooler hot Jupiters to lower pressures. We also utilize general circulation modeling with double-gray radiative transfer to explore how the circulation changes with equilibrium temperature and drag strengths. As expected from our theory, the dayside–nightside temperature differences from our numerical simulations increase with increasing incident stellar flux and drag strengths. We calculate model phase curves using our general circulation models, from which we compare the broadband infrared offset from the substellar point and dayside–nightside brightness temperature differences against observations, finding that strong drag or additional effects (e.g., clouds and/or supersolar metallicities) are necessary to explain many observed phase curves. |
| spellingShingle | Komacek, T Showman, A Tan, X Atmospheric circulation of hot Jupiters: dayside–nightside temperature differences. II. Comparison with observations |
| title | Atmospheric circulation of hot Jupiters: dayside–nightside temperature differences. II. Comparison with observations |
| title_full | Atmospheric circulation of hot Jupiters: dayside–nightside temperature differences. II. Comparison with observations |
| title_fullStr | Atmospheric circulation of hot Jupiters: dayside–nightside temperature differences. II. Comparison with observations |
| title_full_unstemmed | Atmospheric circulation of hot Jupiters: dayside–nightside temperature differences. II. Comparison with observations |
| title_short | Atmospheric circulation of hot Jupiters: dayside–nightside temperature differences. II. Comparison with observations |
| title_sort | atmospheric circulation of hot jupiters dayside nightside temperature differences ii comparison with observations |
| work_keys_str_mv | AT komacekt atmosphericcirculationofhotjupitersdaysidenightsidetemperaturedifferencesiicomparisonwithobservations AT showmana atmosphericcirculationofhotjupitersdaysidenightsidetemperaturedifferencesiicomparisonwithobservations AT tanx atmosphericcirculationofhotjupitersdaysidenightsidetemperaturedifferencesiicomparisonwithobservations |