There are a large number of observations describing aerosol-induced lightning activation in clouds. However, little is known on the precise mechanism aerosols have on atmospheric electrification processes. Aerosols could modify the topography of ice crystals grown by riming, generating nanoscopic curvature asymmetries between colliding ice particle surfaces. By application of the FERMIC (free energy reduction by molecular interface crossing) model, the curvature asymmetries and their effect on mass and charge transfer could be analyzed. Operating prior to contact, the model predicts an elevated transfer of mass and charge when solid aerosols are incorporated in the water drops collected by ice crystals in thunderclouds.