Patchy nightside clouds on ultra-hot Jupiters: General Circulation Model simulations with radiatively active cloud tracers. (arXiv:2205.07834v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Komacek_T/0/1/0/all/0/1">Thaddeus D. Komacek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tan_X/0/1/0/all/0/1">Xianyu Tan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gao_P/0/1/0/all/0/1">Peter Gao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lee_E/0/1/0/all/0/1">Elspeth K.H. Lee</a>
The atmospheres of ultra-hot Jupiters have been characterized in detail
through recent phase curve and low- and high-resolution emission and
transmission spectroscopic observations. Previous numerical studies have
analyzed the effect of the localized recombination of hydrogen on the
atmospheric dynamics and heat transport of ultra-hot Jupiters, finding that
hydrogen dissociation and recombination lead to a reduction in the day-to-night
contrasts of ultra-hot Jupiters relative to previous expectations. In this
work, we add to previous efforts by also considering the localized condensation
of clouds in the atmospheres of ultra-hot Jupiters, their resulting transport
by the atmospheric circulation, and the radiative feedback of clouds on the
atmospheric dynamics. To do so, we include radiatively active cloud tracers
into the existing MITgcm framework for simulating the atmospheric dynamics of
ultra-hot Jupiters. We take cloud condensate properties appropriate for the
high-temperature condensate corundum from CARMA cloud microphysics models. We
conduct a suite of GCM simulations with varying cloud microphysical and
radiative properties, and we find that partial cloud coverage is a ubiquitous
outcome of our simulations. This patchy cloud distribution is inherently set by
atmospheric dynamics in addition to equilibrium cloud condensation, and causes
a cloud greenhouse effect that warms the atmosphere below the cloud deck.
Nightside clouds are further sequestered at depth due to a dynamically induced
high-altitude thermal inversion. We post-process our GCMs with the Monte Carlo
radiative transfer code gCMCRT and find that the patchy clouds on ultra-hot
Jupiters do not significantly impact transmission spectra but can affect their
phase-dependent emission spectra.
The atmospheres of ultra-hot Jupiters have been characterized in detail
through recent phase curve and low- and high-resolution emission and
transmission spectroscopic observations. Previous numerical studies have
analyzed the effect of the localized recombination of hydrogen on the
atmospheric dynamics and heat transport of ultra-hot Jupiters, finding that
hydrogen dissociation and recombination lead to a reduction in the day-to-night
contrasts of ultra-hot Jupiters relative to previous expectations. In this
work, we add to previous efforts by also considering the localized condensation
of clouds in the atmospheres of ultra-hot Jupiters, their resulting transport
by the atmospheric circulation, and the radiative feedback of clouds on the
atmospheric dynamics. To do so, we include radiatively active cloud tracers
into the existing MITgcm framework for simulating the atmospheric dynamics of
ultra-hot Jupiters. We take cloud condensate properties appropriate for the
high-temperature condensate corundum from CARMA cloud microphysics models. We
conduct a suite of GCM simulations with varying cloud microphysical and
radiative properties, and we find that partial cloud coverage is a ubiquitous
outcome of our simulations. This patchy cloud distribution is inherently set by
atmospheric dynamics in addition to equilibrium cloud condensation, and causes
a cloud greenhouse effect that warms the atmosphere below the cloud deck.
Nightside clouds are further sequestered at depth due to a dynamically induced
high-altitude thermal inversion. We post-process our GCMs with the Monte Carlo
radiative transfer code gCMCRT and find that the patchy clouds on ultra-hot
Jupiters do not significantly impact transmission spectra but can affect their
phase-dependent emission spectra.
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