Numerical simulation of cloud-aerosol interactions

The Lagrangian Cloud Model (LCM) is a Large Eddy Simulation model with a two way coupling between the Eulerian (dynamics and thermodynamics) and Lagrangian (microphysics) parts. Since Lagrangian representation of microphysics does not suffer from numerical diffusion in the radius and physical space, and solves the full condensation model, it may be an alternative for the bin approach. In this talk implementation of the collision process in a Lagrangian framework will be discussed and the ability of the model to assess the impact of changes in the aerosol size distribution on the cloud droplet size distributions in stratocumulus clouds observed during VOCALS will be presented.