 |
| Titel |
Aerosol optical hygroscopicity measurements during the 2010 CARES campaign |
| VerfasserIn |
D. B. Atkinson, J. G. Radney, J. Lum, K. R. Kolesar, D. J. Cziczo, M. S. Pekour, Q. Zhang, A. Setyan, A. Zelenyuk, C. D. Cappa |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 8 ; Nr. 15, no. 8 (2015-04-17), S.4045-4061 |
| Datensatznummer |
250119651
|
| Publikation (Nr.) |
 copernicus.org/acp-15-4045-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Measurements of the effect of water uptake on particulate light extinction or
scattering made at two locations during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) study around
Sacramento, CA are reported. The observed influence of water uptake,
characterized through the dimensionless optical hygroscopicity parameter
γ, is compared with calculations constrained by observed particle
size distributions and size-dependent particle composition. A closure
assessment has been carried out that allowed for determination of the average
hygroscopic growth factors (GFs) at 85% relative humidity and the
dimensionless hygroscopicity parameter κ for oxygenated organic
aerosol (OA) and for supermicron particles (defined here as particles with
aerodynamic diameters between 1 and 2.5 microns), yielding
κ = 0.1–0.15 and 0.9–1.0, respectively. The derived range of
oxygenated OA κ values are in line with previous observations. The
relatively large values for supermicron particles is consistent with
substantial contributions of sea-salt-containing particles in this size
range. Analysis of time-dependent variations in the supermicron particle
hygroscopicity suggest that atmospheric processing, specifically chloride
displacement by nitrate and the accumulation of secondary organics on
supermicron particles, can lead to substantial depression of the observed GF. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|