Horizontal quenching at wind speeds ≳500 m/s, plus carbon-sulfur chemistry, explains the MIRI non-detection of night-side methane on WASP-43 b without requiring high metallicity.
Nightside clouds and disequilibrium chemistry on the hot Jupiter WASP-43b
3 Pith papers cite this work, alongside 5 external citations. Polarity classification is still indexing.
abstract
Hot Jupiters are among the best-studied exoplanets, but it is still poorly understood how their chemical composition and cloud properties vary with longitude. Theoretical models predict that clouds may condense on the nightside and that molecular abundances can be driven out of equilibrium by zonal winds. Here we report a phase-resolved emission spectrum of the hot Jupiter WASP-43b measured from 5-12 $\mu$m with JWST's Mid-Infrared Instrument (MIRI). The spectra reveal a large day-night temperature contrast (with average brightness temperatures of 1524$\pm$35 and 863$\pm$23 Kelvin, respectively) and evidence for water absorption at all orbital phases. Comparisons with three-dimensional atmospheric models show that both the phase curve shape and emission spectra strongly suggest the presence of nightside clouds which become optically thick to thermal emission at pressures greater than ~100 mbar. The dayside is consistent with a cloudless atmosphere above the mid-infrared photosphere. Contrary to expectations from equilibrium chemistry but consistent with disequilibrium kinetics models, methane is not detected on the nightside (2$\sigma$ upper limit of 1-6 parts per million, depending on model assumptions).
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astro-ph.EP 3years
2026 3representative citing papers
A quench-pressure parameterisation with two free parameters recovers unbiased C/O and [M/H] from synthetic JWST spectra with vertical mixing, and tentatively detects quenching and photochemical H2S depletion in HD 189733b NIRCam data.
CARMApy provides a Python interface to the ExoCARMA microphysics code, enabling simulation of cloud particle size distributions and rates in exoplanet atmospheres with claimed consistency to prior versions and speed gains of 1.9x single-threaded and 3.8x multithreaded.
citing papers explorer
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Phase-dependent chemistry of WASP-43 b revealed with a suite of one-, two-, and three-dimensional models
Horizontal quenching at wind speeds ≳500 m/s, plus carbon-sulfur chemistry, explains the MIRI non-detection of night-side methane on WASP-43 b without requiring high metallicity.
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A parameterised approach to disequilibrium retrievals in the JWST era: Application to NIRCam observations of HD 189733b
A quench-pressure parameterisation with two free parameters recovers unbiased C/O and [M/H] from synthetic JWST spectra with vertical mixing, and tentatively detects quenching and photochemical H2S depletion in HD 189733b NIRCam data.
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CARMApy: An Open-Source Python Framework for Simulating Microphysical Clouds in Planetary Atmospheres
CARMApy provides a Python interface to the ExoCARMA microphysics code, enabling simulation of cloud particle size distributions and rates in exoplanet atmospheres with claimed consistency to prior versions and speed gains of 1.9x single-threaded and 3.8x multithreaded.