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| Titel |
Decadal trends in aerosol chemical composition at Barrow, Alaska: 1976–2008 |
| VerfasserIn |
P. K. Quinn, T. S. Bates, K. Schulz, G. E. Shaw |
| 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 ; 9, no. 22 ; Nr. 9, no. 22 (2009-11-23), S.8883-8888 |
| Datensatznummer |
250007765
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| Publikation (Nr.) |
 copernicus.org/acp-9-8883-2009.pdf |
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| Zusammenfassung |
| Aerosol measurements at Barrow, Alaska during the past 30 years have
identified the long range transport of pollution associated with Arctic Haze
as well as ocean-derived aerosols of more local origin. Here, we focus on
measurements of aerosol chemical composition to assess (1) trends in Arctic
Haze aerosol and implications for source regions, (2) the interaction between
pollution-derived and ocean-derived aerosols and the resulting impacts on
the chemistry of the Arctic boundary layer, and (3) the response of aerosols
to a changing climate. Aerosol chemical composition measured at Barrow, AK
during the Arctic haze season is compared for the years 1976–1977 and
1997–2008. Based on these two data sets, concentrations of non-sea salt
(nss) sulfate (SO4=) and non-crustal (nc) vanadium (V) have
decreased by about 60% over this 30 year period. Consistency in the
ratios of nss SO4=/ncV and nc manganese (Mn)/ncV between the two
data sets indicates that, although emissions have decreased in the source
regions, the source regions have remained the same over this time period.
The measurements from 1997–2008 indicate that, during the haze season, the
nss SO4= aerosol at Barrow is becoming less neutralized by
ammonium (NH4+) yielding an increasing sea salt aerosol chloride
(Cl−) deficit. The expected consequence is an increase in the release
of Cl atoms to the atmosphere and a change in the lifetime of volatile
organic compounds (VOCs) including methane. In addition, summertime
concentrations of biogenically-derived methanesulfonate (MSA−) and
nss SO4= are increasing at a rate of 12 and 8% per year,
respectively. Further research is required to assess the environmental
factors behind the increasing concentrations of biogenic aerosol. |
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