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| Titel |
Do anthropogenic, continental or coastal aerosol sources impact on a marine aerosol signature at Mace Head? |
| VerfasserIn |
C. O'Dowd, D. Ceburnis, J. Ovadnevaite, A. Vaishya, M. Rinaldi, M. C. Facchini |
| 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 ; 14, no. 19 ; Nr. 14, no. 19 (2014-10-10), S.10687-10704 |
| Datensatznummer |
250119091
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| Publikation (Nr.) |
 copernicus.org/acp-14-10687-2014.pdf |
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| Zusammenfassung |
| Atmospheric aerosols have been sampled and characterised at the Mace Head
north-east (NE) Atlantic atmospheric research station since 1958, with many
interesting phenomena being discovered. However, with the range of new
discoveries and scientific advances, there has been a range of concomitant
criticisms challenging the representativeness of aerosol sampled at the
station compared to that of aerosol over the pristine open-ocean. Two recurring
criticisms relate to the lack of representativeness due to
potentially enhanced coastal sources, possibly leading to artificially high
values of aerosol concentrations, and to the influence of long-range
transport of anthropogenic or continental aerosol and its potential dominance
over, or perturbation of, a natural marine aerosol signal. Here, we review the
results of previous experimental studies on marine aerosols over the NE Atlantic and at Mace Head with the aim of evaluating their representativeness
relative to that of a pristine open-ocean aerosol, i.e. with negligible
anthropogenic/continental influence. Particular focus is given to submicron
organic matter (OM) aerosol. In summary, no correlation was found between OM
and black carbon (BC) in marine air conforming to clean-air sampling
criteria, either at BC levels of 0–15 or 15–50 ng m−3, suggesting
that OM concentrations, up to observed peak values of
3.8 μg m−3, are predominantly natural in origin.
Sophisticated carbon isotope analysis and aerosol mass spectral finger
printing techniques corroborate the conclusion that there is a predominant natural
source of OM, with 80% biogenic source apportionment being observed for
general clean-air conditions, rising to ∼98% during specific
primary marine organic plumes when peak OM mass concentrations
> 3 μg m−3 are observed. Similarly, a maximum
contribution of 20% OM mass coming from non-marine sources was
established by dual carbon isotope analysis. Further, analysis of a series of
experiments conducted at Mace Head conclude that negligible coastal, surf
zone, or tidal effects are discernible in the secondary or primary aerosol
mass residing in the submicron size range for sampling heights of 7 m and
above. The Mace Head marine-air criteria ensure anthropogenic and coastal
effects are sufficiently minimised so as to guarantee a predominant, and
sometimes overwhelming, natural marine aerosol contribution to the total
aerosol population when the criteria are adhered to. |
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