Comparison of Two Approaches to Modeling Atmospheric Aerosol Particle Size Distributions

This paper compares two approaches to modeling (smoothing) aerosol particle size distribution (particle counts for specified diameter intervals): i) the semiparametric approach based on a maximum likelihood fitting of lognormal (LN) mixtures at each time separately, followed by smoothing parameter tracks, ii) the nonparametric approach based on a kernel-like smoothing as an application of the gnostic theory of uncertain data. The specific advantages and disadvantages of both the serniparametric and nonparametric approaches are discussed and illustrated using real data containing a day-long time series of size spectra measurements.