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Titel |
Semi-empirical parameterization of size-dependent atmospheric nanoparticle growth in continental environments |
VerfasserIn |
S. A. K. Häkkinen, H. E. Manninen, T. Yli-Juuti, J. Merikanto, M. K. Kajos, T. Nieminen, S. D. D'Andrea, A. Asmi, J. R. Pierce, M. Kulmala , I. Riipinen |
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 ; 13, no. 15 ; Nr. 13, no. 15 (2013-08-09), S.7665-7682 |
Datensatznummer |
250085616
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Publikation (Nr.) |
copernicus.org/acp-13-7665-2013.pdf |
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Zusammenfassung |
The capability to accurately yet efficiently represent atmospheric
nanoparticle growth by biogenic and anthropogenic secondary organics is a
challenge for current atmospheric large-scale models. It is, however, crucial
to predict nanoparticle growth accurately in order to reliably estimate the
atmospheric cloud condensation nuclei (CCN) concentrations. In this work we
introduce a simple semi-empirical parameterization for sub-20 nm particle
growth that distributes secondary organics to the nanoparticles according to
their size and is therefore able to reproduce particle growth observed in the
atmosphere. The parameterization includes particle growth by sulfuric acid,
secondary organics from monoterpene oxidation (SORGMT) and an
additional condensable vapor of non-monoterpene organics ("background"). The
performance of the proposed parameterization was investigated using ambient
data on particle growth rates in three diameter ranges (1.5–3 nm, 3–7 nm
and 7–20 nm). The growth rate data were acquired from particle/air ion
number size distribution measurements at six continental sites over Europe.
The longest time series of 7 yr (2003–2009) was obtained from a boreal
forest site in Hyytiälä, Finland, while about one year of data
(2008–2009) was used for the other stations. The extensive ambient
measurements made it possible to test how well the parameterization captures
the seasonal cycle observed in sub-20 nm particle growth and to determine
the weighing factors for distributing the SORGMT for different
sized particles as well as the background mass flux (concentration). Besides
the monoterpene oxidation products, background organics with a concentration
comparable to SORGMT, around 6 × 107 cm−3
(consistent with an additional global SOA yield of 100 Tg yr−1) was
needed to reproduce the observed nanoparticle growth. Simulations with global
models suggest that the "background" could be linked to secondary biogenic
organics that are formed in the presence of anthropogenic pollution. |
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