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| Titel |
Oxalic acid as a heterogeneous ice nucleus in the upper troposphere and its indirect aerosol effect |
| VerfasserIn |
B. Zobrist, C. Marcolli, T. Koop, B. P. Luo, D. M. Murphy, U. Lohmann, A. A. Zardini, U. K. Krieger, T. Corti, D. J. Cziczo, S. Fueglistaler, P. K. Hudson, D. S. Thomson, T. Peter |
| 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. 10 ; Nr. 6, no. 10 (2006-07-27), S.3115-3129 |
| Datensatznummer |
250004020
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| Publikation (Nr.) |
 copernicus.org/acp-6-3115-2006.pdf |
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| Zusammenfassung |
| Heterogeneous ice freezing points of aqueous solutions containing various
immersed solid dicarboxylic acids (oxalic, adipic, succinic, phthalic and
fumaric) have been measured with a differential scanning calorimeter. The
results show that only the dihydrate of oxalic acid (OAD) acts as a
heterogeneous ice nucleus, with an increase in freezing temperature between 2
and 5 K depending on solution composition. In several field
campaigns, oxalic acid enriched particles have been detected in the upper
troposphere with single particle aerosol mass spectrometry. Simulations with
a microphysical box model indicate that the presence of OAD may reduce the
ice particle number density in cirrus clouds by up to ~50% when
compared to exclusively homogeneous cirrus formation without OAD. Using the
ECHAM4 climate model we estimate the global net radiative effect caused by
this heterogeneous freezing to result in a cooling as high as
−0.3 Wm−2. |
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