The need for small-scale turbulence in atmospheres of substellar objects
Abstract
Brown dwarfs and giant gas planets are substellar objects whose spectral appearance is determined by the chemical composition of the gas and the solids/liquids in the atmosphere. Atmospheres of substellar objects possess two major scale regimes: large-scale convective motions + gravitational settling and small-scale turbulence + dust formation. Turbulence initiates dust formation spot-like on small scale, while the dust feeds back into the turbulent fluid field by its strong radiative cooling. Small, imploding dust containing areas result which eventually become isothermal. Multi-dimensional simulations show that these small-scale dust structures gather into large-scale structures, suggesting the formation of clouds made of dirty dust grains. The chemical composition of the grains, and thereby the chemical evolution of the gas phase, is a function of temperature and depends on the grain's history.
Citation
Helling , C 2005 , The need for small-scale turbulence in atmospheres of substellar objects . in F Kupka & W Hillebrandt (eds) , Proceedings of the Workshop on "Interdisciplinary Aspects of Turbulence" Ringberg Castle, Tegernsee, Germany, April 18 - 22, 2005 . Max-Planck-Institut für Astrophysik , Garching , pp. 152-158 , Talk at Ringberg workshop on "Interdisciplinary Aspects of Turbulence" , Tegernsee , Bavaria , Germany , 18/04/05 . < http://arxiv.org/abs/astro-ph/0506204v1 > workshop
Publication
Proceedings of the Workshop on "Interdisciplinary Aspects of Turbulence" Ringberg Castle, Tegernsee, Germany, April 18 - 22, 2005
Type
Conference item
Rights
Copyright 2005 the Author.
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