 |
| Titel |
Saharan dust events at the Jungfraujoch: detection by wavelength dependence of the single scattering albedo and first climatology analysis |
| VerfasserIn |
M. Collaud Coen, E. Weingärtner, D. Schaub, C. Hueglin, C. Corrigan, S. Henning, M. Schwikowski, U. Baltensperger |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 4, no. 11/12 ; Nr. 4, no. 11/12 (2004-12-08), S.2465-2480 |
| Datensatznummer |
250001424
|
| Publikation (Nr.) |
 copernicus.org/acp-4-2465-2004.pdf |
|
|
|
|
|
| Zusammenfassung |
| Scattering and absorption coefficients have been measured continuously at
several wavelengths since March 2001 at the high altitude site Jungfraujoch
(3580ma.s.l.). From these data, the wavelength dependences of the
Ångström exponent and particularly of the single scattering albedo are
determined. While the exponent of the single scattering albedo usually
increases with wavelength, it decreases with wavelength during Saharan dust
events (SDE) due to the greater size of the mineral aerosol particles and
their different chemical composition. This change in the sign of the single
scattering exponent turns out to be a sensitive means for detecting Saharan
dust events. The occurrence of SDE detected by this new method was confirmed
by visual inspection of filter colors and by studying long-range
back-trajectories. An examination of SDE over a 22-month period shows that
SDE are more frequent during the March-June period as well as during October
and November. The trajectory analysis indicated a mean traveling time of
96.5h, with the most important source countries situated in the
northern and north-western part of the Saharan desert. Most of the SDE do
not lead to a detectable increase of the 48-h total suspended particulate
matter (TSP) concentration at the Jungfraujoch. During Saharan dust events,
the average contribution of this dust to hourly TSP at the Jungfraujoch is
16µg/m3, which corresponds to an annual mean of 0.8µg/m3 or 24% of TSP. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|