Atmos. Chem. Phys. Discuss., 11, 2077-2122, 2011
www.atmos-chem-phys-discuss.net/11/2077/2011/
doi:10.5194/acpd-11-2077-2011
© Author(s) 2011. This work is distributed
under the Creative Commons Attribution 3.0 License.
Review Status
This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Atmospheric new particle formation: real and apparent growth of neutral and charged particles
J. Leppä1, T. Anttila1, V.-M. Kerminen1, M. Kulmala2, and K. E. J. Lehtinen3
1Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland
2Department of Physics, P.O. Box 64, 00014, University of Helsinki, Finland
3Finnish Meteorological Institute, Kuopio Unit, and University of Eastern Finland, Department of Physics and Mathematics, P.O. Box 1627, 70211 Kuopio, Finland

Abstract. In this study we have provided simple analytical formulae to estimate the growth rate of a nucleation mode due to self-coagulation and the apparent growth rate due to coagulation scavenging by larger particles. These formulae were used on a set of simulations covering a wide range of atmospheric conditions. The modal growth rates were determined from the simulation results by summing the contribution of each process, by calculating the increase rate in the count mean diameter of the mode and by following the peak concentration of the mode. The results of these three methods were compared with each other and the means used to estimate the growth rate due to self-coagulation and coagulation scavenging were found to work quite well. We also investigated the role of charged particles and electric interactions in the growth of a nucleation mode. Charged particles were found to increase the growth rate due to both self-coagulation and coagulation scavenging by a factor of ~1.5 to 2. In case of increased condensation onto charged particles, the total condensational growth rate of a nucleation mode may increase significantly in the very early steps of the growth. The analytical formulae provided by this paper were designed to provide the growth rates due to different processes from aerosol dynamic simulations, but the same principles can be used to determine the growth rates from measurement data.

Citation: Leppä, J., Anttila, T., Kerminen, V.-M., Kulmala, M., and Lehtinen, K. E. J.: Atmospheric new particle formation: real and apparent growth of neutral and charged particles, Atmos. Chem. Phys. Discuss., 11, 2077-2122, doi:10.5194/acpd-11-2077-2011, 2011.
 
Search ACPD
Discussion Paper
    XML
    Citation
    Final Revised Paper
    Share