The Influence of Dust Formation Modelling on Na I and K I Line Profiles   in Substellar Atmospheres
  We aim to understand the correlation between cloud formation and alkali line formation in substellar atmospheres.We perform line profile calculations for Na I and K I based on the coupling of our kinetic model for the formation and composition of dust grains with 1D radiative transfer calculations in atmosphere models for brown dwarfs and giant gas planets. The Na I and K I line profiles sensibly depend on the way clouds are treated in substellar atmosphere simulations. The kinetic dust formation model results in the highest pseudo-continuum compared to the limiting cases. 
C.M.S.Johnas, Ch.Helling, M.Dehn, P.Woitke, P.H.Hauschildt