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| Titel |
Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms |
| VerfasserIn |
S.-L. Sihto, M. Kulmala  , V.-M. Kerminen, M. Maso, T. Petäjä, I. Riipinen, H. Korhonen, F. Arnold, R. Janson, M. Boy, A. Laaksonen, K. E. J. Lehtinen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 12 ; Nr. 6, no. 12 (2006-09-11), S.4079-4091 |
| Datensatznummer |
250004107
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| Publikation (Nr.) |
 copernicus.org/acp-6-4079-2006.pdf |
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| Zusammenfassung |
| We have investigated the formation and early growth of atmospheric secondary
aerosol particles building on atmospheric measurements. The measurements were
part of the QUEST 2 campaign which took place in spring 2003 in
Hyytiälä (Finland). During the campaign numerous aerosol particle
formation events occurred of which 15 were accompanied by gaseous sulphuric
acid measurements. Our detailed analysis of these 15 events is focussed on
nucleation and early growth (to a diameter of 3 nm) of fresh particles. It
revealed that new particle formation seems to be a function of the gaseous
sulphuric acid concentration to the power from one to two when the time delay
between the sulphuric acid and particle number concentration is taken into
account. From the time delay the growth rates of freshly nucleated particles
from 1 nm to 3 nm were determined. The mean growth rate was 1.2 nm/h and it
was clearly correlated with the gaseous sulphuric acid concentration. We
tested two nucleation mechanisms – recently proposed cluster activation and
kinetic type nucleation – as possible candidates to explain the observed
dependences, and determined experimental nucleation coefficients. We found
that some events are dominated by the activation mechanism and some by the
kinetic mechanism. Inferred coefficients for the two nucleation mechanisms
are the same order of magnitude as chemical reaction coefficients in the gas
phase and they correlate with the product of gaseous sulphuric acid and
ammonia concentrations. This indicates that besides gaseous sulphuric acid
also ammonia has a role in nucleation. |
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