Simulations of sulfate aerosol dynamics part II: Model intercomparison

Comparisons between a two-moment, bimodal aerosol model and single-moment sectional models of varying resolution are presented. Predictions from the two-moment model are in good agreement with those from the highest resolution sectional model, whereas lower-resolution single-moment sectional models with a comparable number of variables perform more poorly. The sensitivity of model initializations and predictions to the choice of sectional boundaries is demonstrated, particularly the inability of low-resolution single-moment models to completely capture important features of the distribution. The mean sizes represented in the two-moment model vary in time, responding to changes in the distribution, and thus, this formulation offers greater flexibility in applications to large-scale models.