Precipitating Condensation Clouds in Substellar Atmospheres
Abstract
We present a method to calculate vertical profiles of particle size distributions in condensation clouds of giant planets and brown dwarfs. The method assumes a balance between turbulent diffusion and sedimentation in horizontally uniform cloud decks. Calculations for the Jovian ammonia cloud are compared with results from previous methods. An adjustable parameter describing the efficiency of sedimentation allows the new model to span the range of predictions made by previous models. Calculations for the Jovian ammonia cloud are consistent with observations. Example calculations are provided for water, silicate, and iron clouds on brown dwarfs and on a cool extrasolar giant planet. We find that precipitating cloud decks naturally account for the characteristic trends seen in the spectra and colors of L- and T-type ultracool dwarfs.
Cite
@article{arxiv.astro-ph/0103423,
title = {Precipitating Condensation Clouds in Substellar Atmospheres},
author = {Andrew S. Ackerman and Mark S. Marley},
journal= {arXiv preprint arXiv:astro-ph/0103423},
year = {2009}
}
Comments
33 pages including 7 figures; AASTex; Accepted for publication in Astrophysical Journal, tentatively scheduled for v556 n1 July 20, 2001 . Plotting error in Fig 5 corrected; slight modification to Fig 5 dicussion in text