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| Titel |
On the sub-micron aerosol size distribution in a coastal-rural site at El Arenosillo Station (SW – Spain) |
| VerfasserIn |
M. Sorribas, B. A. Morena, B. Wehner, J. F. López, N. Prats, S. Mogo, A. Wiedensohler, V. E. Cachorro |
| 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 ; 11, no. 21 ; Nr. 11, no. 21 (2011-11-10), S.11185-11206 |
| Datensatznummer |
250010182
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| Publikation (Nr.) |
 copernicus.org/acp-11-11185-2011.pdf |
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| Zusammenfassung |
| This study focuses on the analysis of the sub-micron aerosol characteristics
at El Arenosillo Station, a rural and coastal environment in South-western
Spain between 1 August 2004 and 31 July 2006 (594 days). The mean total
concentration (NT) was 8660 cm−3 and the mean concentrations in
the nucleation (NNUC), Aitken (NAIT) and accumulation (NACC)
particle size ranges were 2830 cm−3, 4110 cm−3 and 1720 cm−3,
respectively. Median size distribution was characterised by a single-modal
fit, with a geometric diameter, median number concentration and geometric
standard deviation of 60 nm, 5390 cm−3 and 2.31, respectively.
Characterisation of primary emissions, secondary particle formation, changes
to meteorology and long-term transport has been necessary to understand the
seasonal and annual variability of the total and modal particle
concentration. Number concentrations exhibited a diurnal pattern with
maximum concentrations around noon. This was governed by the concentrations
of the nucleation and Aitken modes during the warm seasons and only by the
nucleation mode during the cold seasons. Similar monthly mean total
concentrations were observed throughout the year due to a clear inverse
variation between the monthly mean NNUC and NACC. It was related
to the impact of desert dust and continental air masses on the monthly mean
particle levels. These air masses were associated with high values of
NACC which suppressed the new particle formation (decreasing
NNUC). Each day was classified according to a land breeze flow or a
synoptic pattern influence. The median size distribution for desert dust and
continental aerosol was dominated by the Aitken and accumulation modes, and
marine air masses were dominated by the nucleation and Aitken modes.
Particles moved offshore due to the land breeze and had an impact on the
particle burden at noon, especially when the wind was blowing from the NW
sector in the morning during summer time. This increased NNUC and
NAIT by factors of 3.1 and 2.4, respectively. Nucleation events with
the typical "banana" shape were characterised by a mean particle nucleation
rate of 0.74 cm−3 s−1, a mean growth rate of 1.96 nm h−1 and
a mean total duration of 9.25 h (starting at 10:55 GMT and ending at 20:10 GMT). They were observed for 48 days. Other nucleation events were
identified as those produced by the emissions from the industrial areas
located at a distance of 35 km. They were observed for 42 days. Both
nucleation events were strongly linked to the marine air mass origin. |
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