 |
| Titel |
The role of organic aerosols in homogeneous ice formation |
| VerfasserIn |
B. Kärcher, T. Koop |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 5, no. 3 ; Nr. 5, no. 3 (2005-03-03), S.703-714 |
| Datensatznummer |
250002502
|
| Publikation (Nr.) |
 copernicus.org/acp-5-703-2005.pdf |
|
|
|
|
|
| Zusammenfassung |
| Recent field observations suggest that the fraction of
organic-containing aerosol particles in ice cloud particles is
diminished when compared to the background aerosol prior to
freezing. In this work, we use model calculations to investigate
possible causes for the observed behavior. In particular,
homogeneous freezing processes in cooling air parcels containing
aqueous inorganic particles and organic particles are studied
with a detailed microphysical model. A disparate water uptake and
resulting size differences that occur between organic and
inorganic particles prior to freezing are identified as the most
likely reason for the poor partitioning of organic aerosols into
the ice phase. The differences in water uptake can be caused by
changes in the relationship between solute mass fraction and water
activity of the supercooled liquid phase, by modifications of the
accommodation coefficient for water molecules, or by a combination
thereof. The behavior of peak ice saturation ratios and total ice
crystal number concentrations is examined, and the dependence of
the results on cooling rate is investigated. Finally, processes
are discussed that could possibly modify the homogeneous freezing
behavior of organic particles. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|