|
Titel |
Laboratory studies of collection efficiency of sub-micrometer aerosol particles by cloud droplets on a single-droplet basis |
VerfasserIn |
K. Ardon-Dryer, Y.-W. Huang, D. J. Cziczo |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1680-7316
|
Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 16 ; Nr. 15, no. 16 (2015-08-19), S.9159-9171 |
Datensatznummer |
250119973
|
Publikation (Nr.) |
copernicus.org/acp-15-9159-2015.pdf |
|
|
|
Zusammenfassung |
An experimental setup has been constructed to measure the collection
efficiency (CE) of sub-micrometer aerosol particles by cloud droplets.
Droplets of a dilute aqueous ammonium sulfate solution with an average radius
of 21.6 μm fall freely into a chamber and collide with
sub-micrometer polystyrene latex (PSL) sphere particles of known
sizes and concentrations. Two relative humidity (RH) conditions,
15 ± 3 % and 88 ± 3 %, hereafter termed "low" and
"high", respectively, were varied with different particles sizes and
concentrations. After passing through the chamber, the droplets and aerosol
particles were sent to the Particle Analysis by Laser Mass Spectrometry
(PALMS) instrument to determine chemical compositions on a single-droplet
basis. "Coagulated droplets" (droplets that collected aerosols) had mass
spectra that contained signatures from both an aerosol particle and a droplet
residual. CE values range from 2.0 × 10−1 to 1.6 for the low-RH
case and from 1.5 × 10−2 to 9.0 × 10−2 for the
high-RH case. CE values were, within experimental uncertainty, independent of
the aerosol concentrations. CE values in this study were found to be in
agreement with previous experimental and theoretical studies. To our
knowledge, this is the first collection experiment performed on a
single-droplet basis with atmospherically relevant conditions such as droplet
sizes, droplet charges and flow. |
|
|
Teil von |
|
|
|
|
|
|