Aerosol Science 33 (2002) 391–399 www.elsevier.com/locate/jaerosci Technical note Test of the applicability of Kulmala’s analytical expression for the mass ux of growing droplets in highly supersaturated systems: growth of homogeneously nucleated water droplets Alexander Fladerer a , Markku Kulmala b , Reinhard Strey a ; ∗ a Institut f ur Physikalische Chemie, Universit at zu K oln, Luxemburger Strae 116, D-50939 K oln, Germany b Department of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki, Finland Received 23 May 2001; accepted 13 July 2001 Abstract The formation of aerosols proceeds through nucleation, growth and ageing stages. The understanding of nucleation and droplet growth is essential for handling the more complex atmospheric condensation processes. Following the approach of Fuchs and Sutugin, Fladerer and Strey reported in a previous paper, calculations of theoretical growth curves are performed. Calculated growth curves and experimental data on homogeneously nucleated droplets were shown to agree quantitatively. The analytical mass ux expression derived earlier by Kulmala, which implicitly includes the heat ux to the droplet due to the latent heat of condensation, yields growth curves similar to those obtained according to Fuchs and Sutugin for the extreme conditions of homogeneous nucleation (small initial droplet radii, high supersaturations). We show in this note that Kulmala’s formula is applicable to all growth regimes and to initial conditions of high supersaturation, for which it was not expected to work properly. c  2001 Elsevier Science Ltd. All rights reserved. 1. Introduction The experimental investigation of droplet growth has a long tradition. Expansion cloud cham- bers were used as major technique (e.g. Vietti & Schuster 1973a,b; Wagner, 1974, 1975; Vietti & Fastook, 1974, 1975, 1976; Rudolf et al., 2001). However, most growth experiments were executed using heterogeneous nuclei with growth starting at radii much larger than the droplets formed by homogeneous nucleation. Growth data for homogeneously nucleated droplets have so ∗ Corresponding author. Tel.: +49-221-470-4458; fax: +49-221-470-5104. E-mail address: rstrey@uni-koeln.de (R. Strey). 0021-8502/01/$-see front matter c  2001 Elsevier Science Ltd. All rights reserved. PII:S0021-8502(01)00178-1