Author(s)

A. Fassi-Fihri, K. Suhre & R. Rosset

Abstract

A sectional model is used to simulate the internal/external mixing of at- mospheric aerosol particles by coagulation. The model consists initially in two externally mixed particle types made of pure substances A and B which collide to form a third population of internally mixed particles that contains all externally mixed components. For testing purposes, an exact solution is developed that gives the total number concentration of each type of par- ticles for a constant coagulation kernel. Good agreement is found between the predicted and the exact total number concentrations. The model is then applied to simulate the evolution of a plume with mixing between soot arid hygroscopic particles. Optical and hygroscopic proper- ties are calculated for all types of particles to bring out their sensitivity to

Keywords