Change search
ReferencesLink to record
Permanent link

Direct link
Growth rates of atmospheric molecular clusters based on appearance times and collision-evaporation fluxes: Growth by monomers
Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
2014 (English)In: Journal of Aerosol Science, ISSN 0021-8502, E-ISSN 1879-1964, Vol. 78, 55-70 p.Article in journal (Refereed) Published
Abstract [en]

Formation of secondary atmospheric aerosol particles starts with the formation and growth of small molecular clusters. The probability that freshly formed clusters reach larger sizes depends on the rate at which they grow with respect to the rate at which they are lost on pre-existing surfaces. At present, advances in condensation particle counter and mass spectrometer techniques enable the observation of cluster growth via time evolution of size resolved cluster concentrations, and recent studies have utilized measured concentrations to deduce growth rates from the appearance times of different cluster sizes. In this work, we use a dynamic model to simulate the time development of a population of clusters of up to similar to 2 nm in mass diameter, and examine the relation of the growth rates determined from the appearance times to the growth rates calculated from the molecular fluxes between the clusters. This study concentrates on a simple model substance where the clusters grow only by monomer additions and the growth involves a single free energy barrier. Each cluster size defined by the number of molecules in the cluster is explicitly treated instead of dividing the clusters into size classes. Effects of finite size resolution and cluster cluster collisions will be discussed in future work. We find that the growth rates determined with the two different approaches may differ significantly, both quantitatively and qualitatively, for the smallest clusters with the highest evaporation rates. The relative difference decreases with increasing cluster size and decreasing evaporation rate. In addition to cluster size, the difference depends on ambient conditions including external losses and time profile of the monomer concentration. Thus a quantitative comparison requires information not only on the substance, but also on the external conditions. We also show that the size of a critical cluster, corresponding to the maximum of an energy barrier in cluster formation, cannot be inferred from the size-dependent growth rates in realistic conditions.

Place, publisher, year, edition, pages
2014. Vol. 78, 55-70 p.
Keyword [en]
Growth rate, Molecular cluster, Data analysis, Critical cluster, New particle formation
National Category
Earth and Related Environmental Sciences
URN: urn:nbn:se:su:diva-113575DOI: 10.1016/j.jaerosci.2014.08.008ISI: 000347025100005OAI: diva2:786039


Available from: 2015-02-04 Created: 2015-02-04 Last updated: 2015-02-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Riipinen, Ilona
By organisation
Department of Applied Environmental Science (ITM)
In the same journal
Journal of Aerosol Science
Earth and Related Environmental Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 15 hits
ReferencesLink to record
Permanent link

Direct link