Forcing however is dependent upon the climate model, and in the case of aerosols distribution due to atmospheric circulation is estimated independently of the main model itself. (tamino.wordpress.com)
Ginoux, P., L.W. Horowitz, V. Ramaswamy, I.V. Geogdzhayev, B.N. Holben, G. Stenchikov, and X. Tie, 2006: Evaluation of aerosol distribution and optical depth in the Geophysical Fluid Dynamics Laboratory coupled model CM2.1 for present climate. (pubs.giss.nasa.gov)