 |
| Titel |
The Cloud Condensation Nuclei (CCN) properties of 2-methyltetrols and C3-C6 polyols from osmolality and surface tension measurements |
| VerfasserIn |
S. Ekström, B. Nozière, H.-C. Hansson |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 3 ; Nr. 9, no. 3 (2009-02-06), S.973-980 |
| Datensatznummer |
250006824
|
| Publikation (Nr.) |
 copernicus.org/acp-9-973-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
| A significant fraction of the organic material in aerosols is made of highly
soluble compounds such as sugars (mono- and polysaccharides) and polyols
such as the 2-methyltetrols, methylerythritol and methyltreitol. Because of
their high solubility these compounds are considered as potentially
efficient CCN material. For the 2-methyltetrols, this would have important
implications for cloud formation at global scale because they are thought to
be produced by the atmospheric oxidation of isoprene. To investigate this
question, the complete Köhler curves for C3-C6 polyols and the
2-methyltetrols have been determined experimentally from osmolality and
surface tension measurements. Contrary to what was expected, none of these
compounds displayed a higher CCN efficiency than organic acids. Their Raoult
terms show that this limited CCN efficiency is due to their absence of
dissociation in water, this in spite of slight surface-tension effects for
the 2-methyltetrols. Thus, compounds such as saccharides and polyols would
not contribute more to cloud formation than other organic compounds studied
so far. In particular, the presence of 2-methyltetrols in aerosols would not
particularly enhance cloud formation in the atmosphere, in contrary to
recently suggested. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|