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| Titel |
Aerosol processing and CCN formation of an intense Saharan dust plume during the EUCAARI 2008 campaign |
| VerfasserIn |
N. Bègue, P. Tulet, J. Pelon, B. Aouizerats, A. Berger, A. Schwarzenboeck |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 6 ; Nr. 15, no. 6 (2015-03-31), S.3497-3516 |
| Datensatznummer |
250119585
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| Publikation (Nr.) |
 copernicus.org/acp-15-3497-2015.pdf |
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| Zusammenfassung |
| Atmospheric processing and CCN formation of Saharan dust is illustrated
through the analysis of a case of dust transport over northern Europe. This
spread of dust is investigated by combining satellite, airborne and
ground-based observations and the non-hydrostatic meso-scale model Meso-NH.
The altitude of the dust plume during its transport to northwestern Europe
was assessed using the CALIPSO observations and our model results. The major
dust plume was transported toward Mediterranean and European regions between
2 and 5 km above sea level (a.s.l.). This is confirmed by an average particle
depolarization ratio equal to 30%. Due to transport, this layer split
into two layers over northern Europe, and we analyzed in this paper possible
mixing of the European pollution aerosol with dust particles in the lower
layer. The simulations have shown that the lower dust layer has interacted
with the anthropogenic aerosol mainly over Belgium and the Netherlands. The
analyses of numerical simulation results show that mineral dust particles
accumulated soluble material through internal mixing over the Netherlands.
The value of the CCN0.2 / CN ratio obtained over the Netherlands
(~ 70%) is much greater than those observed over the
Saharan region. In addition over the Netherlands, the CCN measurement
reached 14 000 particles cm−3 at 0.63% supersaturation level on 30 May. Our model results reveal that more than 70% of the CCN concentration
observed on 30 May can be explained by the presence of Saharan aged dust.
The study reveals that heterogeneous reactions with inorganic salts
converted this Saharan mineral dust into compounds that were sufficiently
soluble to impact hygroscopic growth and cloud droplet activation over the
Netherlands. |
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