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Titel |
Ternary solution of sodium chloride, succinic acid and water; surface tension and its influence on cloud droplet activation |
VerfasserIn |
J. Vanhanen, A.-P. Hyvärinen, T. Anttila, T. Raatikainen, Y. Viisanen, H. Lihavainen |
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 ; 8, no. 16 ; Nr. 8, no. 16 (2008-08-06), S.4595-4604 |
Datensatznummer |
250006319
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Publikation (Nr.) |
copernicus.org/acp-8-4595-2008.pdf |
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Zusammenfassung |
Surface tension of ternary solution of sodium chloride, succinic acid and
water was measured as a function of both composition and temperature by
using the capillary rise technique. Both sodium chloride and succinic acid
are found in atmospheric aerosols, the former being main constituent of
marine aerosol. Succinic acid was found to decrease the surface tension of
water already at very low concentrations. Sodium chloride increased the
surface tension linearly as a function of the concentration. Surface
tensions of both binary solutions agreed well with the previous
measurements. Succinic acid was found to lower the surface tension even if
sodium chloride is present, indicating that succinic acid, as a surface
active compound, tends to concentrate to the surface. An equation based on
thermodynamical relations was fitted to the data and extrapolated to the
whole concentration range by using estimated surface tensions for pure
compounds. As a result, we obtained an estimate of surface tensions beyond
solubility limits in addition to a fit to the experimental data. The
parameterization can safely be used at temperatures from 10 to 30°C.
These kinds of parameterizations are important for example in atmospheric
nucleation models. To investigate the influence of surface tension on cloud
droplet activation, the surface tension parameterization was included in an
adiabatic air parcel model. Usually in cloud models the surface tension of
pure water is used. Simulations were done for characteristic marine aerosol
size distributions consisting of the considered ternary mixture. We found
that by using the surface tension of pure water, the amount of activated
particles is underestimated up to 8% if particles contain succinic acid
and overestimated it up to 8% if particles contain only sodium chloride.
The surface tension effect was found to increase with increasing updraft
velocity. |
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