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Titel |
Sources of short-lived bromocarbons in the Iberian upwelling system |
VerfasserIn |
S. Raimund, B. Quack, Y. Bozec, M. Vernet, V. Rossi, V. Garçon, Y. Morel, P. Morin |
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 ; 8, no. 6 ; Nr. 8, no. 6 (2011-06-17), S.1551-1564 |
Datensatznummer |
250005956
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Publikation (Nr.) |
copernicus.org/bg-8-1551-2011.pdf |
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Zusammenfassung |
Seawater concentrations of the four brominated trace gases, dibromomethane
(CH2Br2), bromodichloromethane (CHBrCl2),
dibromochloromethane (CHBr2Cl) and bromoform (CHBr3) were measured
at different depths of the water column in the Iberian upwelling off
Portugal during summer 2007. Statistical analysis of the data set revealed
three distinct clusters, caused by different sea surface temperature.
Bromocarbon concentrations were elevated in recently upwelled and aged
upwelled waters (mean values of 30 pmol l−1 for CHBr3), while
concentrations in the open ocean were significantly lower (7.4 pmol l−1
for CHBr3). Comparison with other productive marine areas revealed that
the Iberian upwelling had higher halocarbon concentrations than the
Mauritanian upwelling. However, the concentrations off the Iberian Peninsula
were still much lower than those of coastal macroalgal-influenced waters or
those of Polar regions dominated by cold water adapted diatoms. Correlations
with biological variables and marker pigments indicated that phytoplankton
was a source of bromocarbon in the open ocean. By contrast, in upwelled
water masses along the coast, halocarbons showed weaker correlations to
marker pigments but were significantly influenced by the tidal frequency.
Our results indicate a strong intertidal coastal source of bromocarbon and
transport by surface currents of these enriched waters towards the upwelling
region. |
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