A Numerical Simulation of Wintertime, Orographic Precipitation: Part I. Description of Model Microphysics and Numerical Techniques

Abstract

A numerical model which extends treatment of microphysical cloud processes to more than one level through use of the continuous bin technique is described. A general solution to the diffusion growth equation including latent heat release due to accretion is presented. Collection processes of coalescence, accretion and aggregation, activation of CCN, and ice phase nucleation through sorption and contact freezing nucleation are combined with a diffusion treatment which allows for calculation of the supersaturation in a multi-level framework and with sedimentation of particles between levels.