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| Titel |
Aerosol properties associated with air masses arriving into the North East Atlantic during the 2008 Mace Head EUCAARI intensive observing period: an overview |
| VerfasserIn |
M. Dall'Osto, D. Ceburnis, G. Martucci, J. Bialek, R. Dupuy, S. G. Jennings, H. Berresheim, J. Wenger, R. Healy, M. C. Facchini, M. Rinaldi, L. Giulianelli, E. Finessi, D. Worsnop, M. Ehn, J. Mikkilä, M. Kulmala  , C. D. O'Dowd |
| 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 ; 10, no. 17 ; Nr. 10, no. 17 (2010-09-07), S.8413-8435 |
| Datensatznummer |
250008757
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| Publikation (Nr.) |
 copernicus.org/acp-10-8413-2010.pdf |
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| Zusammenfassung |
| As part of the EUCAARI Intensive Observing Period, a
4-week campaign to measure aerosol physical, chemical and optical
properties, atmospheric structure, and cloud microphysics was conducted from
mid-May to mid-June, 2008 at the Mace Head Atmospheric Research Station,
located at the interface of Western Europe and the N. E. Atlantic and
centered on the west Irish coastline. During the campaign, continental air
masses comprising both young and aged continental plumes were encountered,
along with polar, Arctic and tropical air masses. Polluted-continental
aerosol concentrations were of the order of 3000 cm−3, while background
marine air aerosol concentrations were between 400–600 cm−3. The
highest marine air concentrations occurred in polar air masses in which a 15
nm nucleation mode, with concentration of 1100 cm−3, was observed and
attributed to open ocean particle formation. Continental air submicron
chemical composition (excluding refractory sea salt) was dominated by
organic matter, closely followed by sulphate mass. Although the
concentrations and size distribution spectral shape were almost identical
for the young and aged continental cases, hygroscopic growth factors (GF)
and cloud condensation nuclei (CCN) to total condensation nuclei (CN)
concentration ratios were significantly less in the younger pollution plume,
indicating a more oxidized organic component to the aged continental plume.
The difference in chemical composition and hygroscopic growth factor appear
to result in a 40–50% impact on aerosol scattering coefficients and
Aerosol Optical Depth, despite almost identical aerosol microphysical
properties in both cases, with the higher values been recorded for the more
aged case. For the CCN/CN ratio, the highest ratios were seen in the more
age plume. In marine air, sulphate mass dominated the sub-micron component,
followed by water soluble organic carbon, which, in turn, was dominated by
methanesulphonic acid (MSA). Sulphate concentrations were highest in marine
tropical air – even higher than in continental air. MSA was present at
twice the concentrations of previously-reported concentrations at the same
location and the same season. Both continental and marine air exhibited
aerosol GFs significantly less than ammonium sulphate aerosol pointing to a
significant organic contribution to all air mass aerosol properties. |
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