This is a provisionnal version on 19 September 2005 : please send any comments to Pierre BÃ©nard (you can use the forum linked to this article).
This paper derives the equations for a moist precipitating atmosphere in mass coordinate. The starting point is the paper by Sylvie Malardel on the equations for a precipitating atmosphere in height coordinate. Therefore, basically, this paper deals with the coordinate change from height to mass coordinates for a moist precipitating atmosphere in the framework adopted therein. The technique for the coordinate change is largely taken from Laprise.
It should be outlined that the definition of the mass coordinate itself in a given model is very closely related to the choice of the density appearing in the continuity equation and in the Laplace equation actually used in this model.