Global flow regimes of hot Jupiters
Global flow regimes of hot Jupiters
Context: the atmospheric dynamics of hot and ultrahot Jupiters are influenced by the stellar irradiation they receive, which shapes their atmospheric circulation and the underlying wave structures.
Aims: we aim to investigate how variations in radiative and dynamical timescales influence global flow regimes, atmospheric circulation efficiency, and the interplay of wave structures across a curated sample of hot Jupiters. In particular, we explore a previously predicted transition in the global flow regime, where enhanced stellar irradiation suppresses the smaller-scale wave and eddy features that feed into superrotating jets and ultimately leads to simpler, day-to-night dominated flows.
Methods: we simulated a suite of eight well-studied hot Jupiters with the THOR general circulation model, spanning equilibrium temperatures from about 1100 K to 2400 K. We developed a wavelet-based analysis method to decompose simulated wind fields into their underlying wave modes, which we validated on analytical examples. As a preliminary exploration of the flow regime of ultrahot Jupiters, we performed an additional simulation for WASP-121b, where the mean molecular weight was set to represent an atmosphere dominated by atomic hydrogen.
Results: our results confirm that increasing stellar irradiation diminishes the efficiency of atmospheric heat redistribution and weakens the contribution of smaller-scale eddy modes critical for sustaining superrotation. As equilibrium temperatures rise, large-scale modes dominate the atmospheric circulation, driving a transition from jet-dominated flows toward day-to-night circulation. Additionally, by artificially lowering the mean molecular weight, we partially restore circulation efficiency and reintroduce a more complex, multiscale flow pattern. These findings refine our understanding of how atmospheric circulation evolves with increasing irradiation and composition changes, offering a more nuanced framework for interpreting hot and ultrahot Jupiter atmospheres.
astro-ph.EP, Hydrodynamics, Planets and satellites: atmospheres, Radiative transfer, Waves, Methods: numerical
Akın, C.
25d5593f-2905-4d57-8d69-df2d5ed96b2b
Heng, K.
81312607-a2a4-478d-873c-ad5451ab25a7
Mendonça, J. M.
cb29fe08-eb94-4fad-8eba-eac1c5de491b
Deitrick, R.
7e0f9786-935b-4c3b-8a57-1e8b7b85b075
Gkouvelis, L.
bff5d9f3-a63f-41ec-a763-ccb4ea3fd68f
July 2025
Akın, C.
25d5593f-2905-4d57-8d69-df2d5ed96b2b
Heng, K.
81312607-a2a4-478d-873c-ad5451ab25a7
Mendonça, J. M.
cb29fe08-eb94-4fad-8eba-eac1c5de491b
Deitrick, R.
7e0f9786-935b-4c3b-8a57-1e8b7b85b075
Gkouvelis, L.
bff5d9f3-a63f-41ec-a763-ccb4ea3fd68f
Akın, C., Heng, K., Mendonça, J. M., Deitrick, R. and Gkouvelis, L.
(2025)
Global flow regimes of hot Jupiters.
A&A, 699, [A74].
(doi:10.1051/0004-6361/202453597).
Abstract
Context: the atmospheric dynamics of hot and ultrahot Jupiters are influenced by the stellar irradiation they receive, which shapes their atmospheric circulation and the underlying wave structures.
Aims: we aim to investigate how variations in radiative and dynamical timescales influence global flow regimes, atmospheric circulation efficiency, and the interplay of wave structures across a curated sample of hot Jupiters. In particular, we explore a previously predicted transition in the global flow regime, where enhanced stellar irradiation suppresses the smaller-scale wave and eddy features that feed into superrotating jets and ultimately leads to simpler, day-to-night dominated flows.
Methods: we simulated a suite of eight well-studied hot Jupiters with the THOR general circulation model, spanning equilibrium temperatures from about 1100 K to 2400 K. We developed a wavelet-based analysis method to decompose simulated wind fields into their underlying wave modes, which we validated on analytical examples. As a preliminary exploration of the flow regime of ultrahot Jupiters, we performed an additional simulation for WASP-121b, where the mean molecular weight was set to represent an atmosphere dominated by atomic hydrogen.
Results: our results confirm that increasing stellar irradiation diminishes the efficiency of atmospheric heat redistribution and weakens the contribution of smaller-scale eddy modes critical for sustaining superrotation. As equilibrium temperatures rise, large-scale modes dominate the atmospheric circulation, driving a transition from jet-dominated flows toward day-to-night circulation. Additionally, by artificially lowering the mean molecular weight, we partially restore circulation efficiency and reintroduce a more complex, multiscale flow pattern. These findings refine our understanding of how atmospheric circulation evolves with increasing irradiation and composition changes, offering a more nuanced framework for interpreting hot and ultrahot Jupiter atmospheres.
Text
2505.12111v1
- Author's Original
Text
aa53597-24
- Version of Record
More information
Accepted/In Press date: 16 May 2025
e-pub ahead of print date: 2 July 2025
Published date: July 2025
Keywords:
astro-ph.EP, Hydrodynamics, Planets and satellites: atmospheres, Radiative transfer, Waves, Methods: numerical
Identifiers
Local EPrints ID: 505070
URI: http://eprints.soton.ac.uk/id/eprint/505070
ISSN: 0004-6361
PURE UUID: 6942c429-4b01-437a-9147-5aae395f1dce
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Date deposited: 25 Sep 2025 17:02
Last modified: 26 Sep 2025 02:18
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Contributors
Author:
C. Akın
Author:
K. Heng
Author:
J. M. Mendonça
Author:
R. Deitrick
Author:
L. Gkouvelis
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