A model for particle formation and growth in the atmosphere with molecular resolution in size K. E. J. Lehtinen and M. Kulmala Helsinki University, Dept. Physical Sciences, P.O. Box 64, 00014 Univ. of Helsinki, Finland
Abstract. The formation and growth of atmospheric aerosol particles is considered using an exact
discrete method with molecular resolution in size space. The method is immune to numerical
diffusion problems that are a nuisance for typical simulation methods using a sectional
representation for the particle size distribution. For condensational growth, a slight
modification is proposed for the Fuchs-Sutugin expression, which improves the prediction of
the growth rate of nano-sized particles by as much as a factor of two. The presented method is
applied to particle formation in a Finnish Boreal forest and is shown to capture the essential
features of the dynamics quite nicely. Furthermore, it is shown that the growth of the particles
is roughly linear, which means that the amount of condensable vapour is constant (of the
order 1013 1/m3).
Citation: Lehtinen, K. E. J. and Kulmala, M.: A model for particle formation and growth in the atmosphere with molecular resolution in size, Atmos. Chem. Phys., 3, 251-257, doi:10.5194/acp-3-251-2003, 2003.