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| Titel |
Governing processes for reactive nitrogen compounds in the European atmosphere |
| VerfasserIn |
O. Hertel, C. A. Skjøth, S. Reis, A. Bleeker, R. M. Harrison, J. N. Cape, D. Fowler, U. Skiba, D. Simpson, T. Jickells, M. Kulmala  , S. Gyldenkærne, L. L. Sørensen, J. W. Erisman, M. A. Sutton |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 12 ; Nr. 9, no. 12 (2012-12-04), S.4921-4954 |
| Datensatznummer |
250007448
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| Publikation (Nr.) |
 copernicus.org/bg-9-4921-2012.pdf |
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| Zusammenfassung |
| Reactive nitrogen (Nr) compounds have different fates in the
atmosphere due to differences in the governing processes of physical
transport, deposition and chemical transformation. Nr compounds
addressed here include reduced nitrogen (NHx: ammonia (NH3)
and its reaction product ammonium (NH4+)), oxidized nitrogen
(NOy: nitrogen monoxide (NO) + nitrogen dioxide (NO2) and
their reaction products) as well as organic nitrogen compounds (organic N).
Pollution abatement strategies need to take into account the differences in
the governing processes of these compounds when assessing their impact on
ecosystem services, biodiversity, human health and climate. NOx
(NO + NO2) emitted from traffic affects human health in urban areas
where the presence of buildings increases the residence time in streets. In
urban areas this leads to enhanced exposure of the population to
NOx concentrations. NOx emissions generally have little
impact on nearby ecosystems because of the small dry deposition rates of
NOx. These compounds need to be converted into nitric acid
(HNO3) before removal through deposition is efficient. HNO3 sticks
quickly to any surface and is thereby either dry deposited or incorporated
into aerosols as nitrate (NO3−). In contrast to NOx
compounds, NH3 has potentially high impacts on ecosystems near the main
agricultural sources of NH3 because of its large ground-level
concentrations along with large dry deposition rates. Aerosol phase
NH4+ and NO3− contribute significantly to background
PM2.5 and PM10 (mass of aerosols with an aerodynamic diameter of
less than 2.5 and 10 μm, respectively) with an impact on radiation
balance as well as potentially on human health. Little is known
quantitatively and qualitatively about organic N in the atmosphere, other
than that it contributes a significant fraction of wet-deposited N, and is
present in both gaseous and particulate forms. Further studies are needed to
characterise the sources, air chemistry and removal rates of organic N
emissions. |
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