Work

Precipitating Condensation Clouds in Substellar Atmospheres

Year: 2001

Type: article

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 of L- and T-type ultracool dwarfs.

Source: The Astrophysical Journal

DOI: 10.1086/321540

Authors: Andrew S. Ackerman, Mark S. Marley

Institutions: Ames Research Center, New Mexico State University

Language: English

Topic: Stellar, planetary, and galactic studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: National Science Foundation, National Aeronautics and Space Administration

Awards: MODEL ATMOSPHERES AND SPECTRA OF THE L-DWARFS (ATP 99), MODEL ATMOSPHERES AND SPECTRA FOR EXTRASOLAR GIANT PLANETS AND BROWN DWARFS, Innovations in Giant Planet Evolution Theoretical Models and Undergraduate Science Literacy, NSTARS: Understanding the L- and T-dwarfs