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| Titel |
Particle size distributions in the Eastern Mediterranean troposphere |
| VerfasserIn |
N. Kalivitis, W. Birmili, M. Stock, B. Wehner, A. Maßling, A. Wiedensohler, E. Gerasopoulos, N. Mihalopoulos |
| 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 ; 8, no. 22 ; Nr. 8, no. 22 (2008-11-24), S.6729-6738 |
| Datensatznummer |
250006461
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| Publikation (Nr.) |
 copernicus.org/acp-8-6729-2008.pdf |
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| Zusammenfassung |
| Atmospheric particle size distributions were measured on Crete
island, Greece in the Eastern Mediterranean during an intensive
field campaign between 28 August and 20 October, 2005. Our
instrumentation combined a differential mobility particle sizer
(DMPS) and an aerodynamic particle sizer (APS) and measured number
size distributions in the size range 0.018 μm–10 μm.
Four time periods with distinct aerosol characteristics were
discriminated, two corresponding to marine and polluted air
masses, respectively. In marine air, the sub-μm size
distributions showed two particle modes centered at 67 nm and
195 nm having total number concentrations between 900 and
2000 cm−3. In polluted air masses, the size distributions
were mainly unimodal with a mode typically centered at 140 nm,
with number concentrations varying between 1800 and 2900 cm−3. Super-μm particles showed number concentrations in
the range from 0.01 to 2.5 cm−3 without any clear relation to
air mass origin. A small number of short-lived particle nucleation
events were recorded, where the calculated particle formation
rates ranged between 1.1–1.7 cm−3 s−1. However, no
particle nucleation and growth events comparable to those typical
for the continental boundary layer were observed. Particles
concentrations (Diameter <50 nm) were low compared to
continental boundary layer conditions with an average
concentration of 300 cm−3. The production of sulfuric acid
and its subsequently condensation on preexisting particles was
examined with the use of a simplistic box model. These
calculations suggested that the day-time evolution of the Aitken
particle population was governed mainly by coagulation and that
particle formation was absent during most days. |
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