Global flow regimes of hot Jupiters
arXiv:2505.12111 · doi:10.1051/0004-6361/202453597
Abstract
In hot and ultra-hot Jupiters, stellar irradiation is a primary driver of atmospheric circulation and the wave structures that sustain it. 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 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. We simulate a suite of eight well-studied hot Jupiters with the THOR general circulation model, spanning equilibrium temperatures from about K to K. We develop a wavelet-based analysis method to decompose simulated wind fields into their underlying wave modes, which we validate on analytical examples. As a preliminary exploration of the flow regime of ultra-hot Jupiters, we perform an additional simulation for WASP-121b, where the mean molecular weight is set to represent an atmosphere dominated by atomic hydrogen. Our results confirm that increasing stellar irradiation diminishes atmospheric heat redistribution efficiency and weakens contributions from smaller-scale modes that are critical to sustain 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, multi-scale 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 ultra-hot Jupiter atmospheres.
Accepted by A&A. 23 pages, 20 figures, 2 tables
References in corpus (19)
- Improved parameters for extrasolar transiting planets
- Accurate, Empirical Radii and Masses of Planets and their Host Stars with Gaia Parallaxes
- Atmospheric Dynamics of Hot Exoplanets
- The Atmospheric Circulation of Ultra-hot Jupiters
- Self-luminous and irradiated exoplanetary atmospheres explored with HELIOS
- The UK Met Office GCM with a sophisticated radiation scheme applied to the hot Jupiter HD 209458b
- 3D Structures of equatorial waves and the resulting superrotation in the atmosphere of a tidally locked hot Jupiter
- The rotational and divergent components of atmospheric circulation on tidally locked planets
- An Infrared Census of DUST in Nearby Galaxies with Spitzer (DUSTiNGS), II. Discovery of Metal-poor Dusty AGB Stars
- Atmospheric circulation of brown dwarfs and directly imaged exoplanets driven by cloud radiative feedback: global and equatorial dynamics
- THOR: A New and Flexible Global Circulation Model to Explore Planetary Atmospheres
- Simulating gas giant exoplanet atmospheres with Exo-FMS: Comparing semi-grey, picket fence and correlated-k radiative-transfer schemes
- Modons on Tidally Synchronised Extrasolar Planets
- The Mantis Network II: Examining the 3D high-resolution observable properties of the UHJs WASP-121b and WASP-189b through GCM modelling
- The stable climate of KELT-9b
- Temperature Structures Associated with Different Components of the Atmospheric Circulation on Tidally Locked Exoplanets
- The THOR+HELIOS general circulation model: multi-wavelength radiative transfer with accurate scattering by clouds/hazes
- Analytical Models of Exoplanetary Atmospheres. IV. Improved Two-stream Radiative Transfer for the Treatment of Aerosols
- Examining NHD vs QHD in the GCM THOR with non-grey radiative transfer for the hot Jupiter regime