Kevin Heng, Dargan M. W. Frierson, Peter J. Phillipps
Improving upon our purely dynamical work, we present three-dimensional
simulations of the atmospheric circulation on Earth-like (exo)planets and hot
Jupiters using the GFDL-Princeton Flexible Modeling System (FMS). As the first
steps away from the dynamical benchmarks of Heng, Menou & Phillipps (2011), we
add dual-band radiative transfer and dry convective adjustment schemes to our
computational setup. Our treatment of radiative transfer assumes stellar
irradiation to peak at a wavelength shorter than and distinct from that at
which the exoplanet re-emits radiation ("shortwave" versus "longwave"), and
also uses a two-stream approximation. Convection is mimicked by adjusting
unstable lapse rates to the dry adiabat. The bottom of the atmosphere is
bounded by a uniform slab with a finite thermal inertia. For our models of hot
Jupiters, we include an analytical formalism for calculating
temperature-pressure profiles, in radiative equilibrium, which accounts for the
effect of collision-induced absorption via a single parameter. We discuss our
results within the context of: the predicted temperature-pressure profiles and
the absence/presence of a temperature inversion; the possible maintenance, via
atmospheric circulation, of the putative high-altitude, shortwave absorber
expected to produce these inversions; the angular/temporal offset of the hot
spot from the substellar point, its robustness to our ignorance of
hyperviscosity and hence its utility in distinguishing between different hot
Jovian atmospheres; and various zonal-mean flow quantities. Our work bridges
the gap between three-dimensional simulations which are purely dynamical and
those which incorporate multi-band radiative transfer, thus contributing to the
construction of a required hierarchy of three-dimensional theoretical models.
View original:
http://arxiv.org/abs/1105.4065
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