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| Titel |
Quantifying importance and scaling effects of atmospheric deposition of inorganic fixed nitrogen for the eutrophic Black Sea |
| VerfasserIn |
A. Varenik, S. Konovalov, S. Stanichny |
| 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 ; 12, no. 21 ; Nr. 12, no. 21 (2015-11-12), S.6479-6491 |
| Datensatznummer |
250118163
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| Publikation (Nr.) |
 copernicus.org/bg-12-6479-2015.pdf |
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| Zusammenfassung |
Wet atmospheric depositions have been collected in a rural (Katsiveli) and
urban (Sevastopol) location at the Crimean coast of the Black Sea from 2003
to 2008. Samples, 217 from Katsiveli and 228 from Sevastopol, have been
analysed for inorganic fixed nitrogen (nitrate, nitrite, and ammonium). Data
have revealed almost equal contributions of ammonium (44–45 %) and
nitrate (52–53 %) and minor contribution of nitrite
(2–4 %) for both rural and urban samples. The volume weight mean
concentration of inorganic fixed nitrogen (IFN) in urban samples
(2.51 mg N L−1) is about 2-fold of that content in rural
samples (1.16 mg N L−1). Seasonal variations in volume weight
mean monthly concentrations have been revealed for both locations with
maximum concentrations in winter and minimum values in summer, but
intra-annual variations are statistically significant for only urban samples.
The average annual deposition of IFN with atmospheric precipitations on the
surface of the Black Sea is about
0.31 × 106 t N yr−1
(0.75 t N km−2 yr−1), which is on average 39 %
of the riverine input. It does vary in space and time. The relative
importance of the atmospheric input increases from coastal to open areas and
from winter to summer. Deposition of IFN with wet atmospheric precipitations
proportionally increases the concentration of chlorophyll a, as it is traced
from satellite data. The traced increase in the concentration of
chlorophyll a has reached 1.5-fold for mesoscale processes. In case of
individual rain events supporting up to 50–60 mg N m−2, the
influence of IFN deposition is up to 5 % at the north-western shelf
of the Black Sea, where most of the river-born IFN is loaded. In the central
areas of the sea, where the amount of IFN in summer is low, the contribution
of individual rainfall can reach 35 %. The input of IFN to the Black
Sea has potential to enhance 2-fold the level of primary production. |
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