 |
| Titel |
Droplet activation of wet particles: development of the Wet CCN approach |
| VerfasserIn |
S. Nakao, S. R. Suda, M. Camp, M. D. Petters, S. M. Kreidenweis |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 7 ; Nr. 7, no. 7 (2014-07-22), S.2227-2241 |
| Datensatznummer |
250115854
|
| Publikation (Nr.) |
 copernicus.org/amt-7-2227-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Relationships between critical supersaturation required for activation and
particle dry diameter have been the primary means for experimentally
characterizing cloud condensation nuclei (CCN) activity; however, use of the
dry diameter inherently limits the application to cases where the dry
diameter can be used to accurately estimate solute volume. This study
challenges the requirement and proposes a new experimental approach, Wet
CCN, for studying CCN activity without the need for a drying step. The new
approach directly measures the subsaturated portion of the Köhler
curves. The experimental setup consists of a humidity-controlled
differential mobility analyzer and a CCN counter; wet diameter equilibrated
at known relative humidity is used to characterize CCN activity instead of
the dry diameter. The experimental approach was validated against ammonium
sulfate, glucose, and nonspherical ammonium oxalate monohydrate. Further,
the approach was applied to a mixture of nonspherical iodine oxide
particles. The Wet CCN approach successfully determined the hygroscopicity
of nonspherical particles by collapsing them into spherical, deliquesced
droplets. We further show that the Wet CCN approach offers unique insights
into the physical and chemical impacts of the aqueous phase on CCN activity; a
potential application is to investigate the impact of
evaporation/co-condensation of water-soluble semivolatile species on CCN
activity. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|