The Intrinsic Temperature and RadiativeConvective Boundary Depth in the Atmospheres of Hot Jupiters
Abstract
In giant planet atmosphere modeling, the intrinsic temperature T _{int} and radiativeconvective boundary (RCB) are important lower boundary conditions. Often in onedimensional radiativeconvective models and in threedimensional general circulation models it is assumed that T _{int} is similar to that of Jupiter itself, around 100 K, which yields an RCB around 1 kbar for hot Jupiters. In this work, we show that the inflated radii, and hence high specific entropy interiors (811 k _{ b }/baryon), of hot Jupiters suggest much higher T _{int}. Assuming the effect is primarily due to current heating (rather than delayed cooling), we derive an equilibrium relation between T _{eq} and T _{int}, showing that the latter can take values as high as 700 K. In response, the RCB moves upward in the atmosphere. Using onedimensional radiativeconvective atmosphere models, we find RCBs of only a few bars, rather than the kilobar typically supposed. This much shallower RCB has important implications for the atmospheric structure, vertical and horizontal circulation, interpretation of atmospheric spectra, and the effect of deep cold traps on cloud formation.
 Publication:

The Astrophysical Journal
 Pub Date:
 October 2019
 DOI:
 10.3847/20418213/ab43d0
 arXiv:
 arXiv:1907.07777
 Bibcode:
 2019ApJ...884L...6T
 Keywords:

 Exoplanet atmospheres;
 Extrasolar gas giants;
 Exoplanet structure;
 Exoplanet evolution;
 487;
 509;
 495;
 491;
 Astrophysics  Earth and Planetary Astrophysics
 EPrint:
 6 pages, 4 figures, accepted to ApJ Letters. This version corrects the constants in equation 3