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Titel |
Fluxes of carbon and nutrients to the Iceland Sea surface waters and inferred primary productivity and stoichiometry |
VerfasserIn |
Emil Jeansson, Richard Bellerby, Helene Frigstad, Sólveig R. Ólafsdóttir, Jon Olafsson, Ingunn Skjelvan |
Konferenz |
EGU General Assembly 2014
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 16 (2014) |
Datensatznummer |
250097127
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Publikation (Nr.) |
EGU/EGU2014-12674.pdf |
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Zusammenfassung |
Fluxes of carbon and nutrients to the upper 100 m of the Iceland Sea are evaluated. The study
utilises hydro-chemical data from the quarterly sampled Iceland Sea time-series
station (68.00 °N, 12.67 °W), for the years between 1993 and 2006. By comparing
data of dissolved inorganic carbon (DIC) and nutrients in the surface layer (upper
100 m), and a sub-surface layer (100-200 m), we calculate monthly deficits in the
surface, and use this to deduce the fluxes into and out of the surface layer that affect
the deficit: vertical mixing, horizontal advection, air-sea exchange, and biological
activity. The deficits show a clear seasonality with a minimum in winter, when the
mixed layer is at the deepest, and a maximum in September, when biological uptake
has removed much of the nutrients. The annual vertical fluxes of DIC and nitrate
amounts to 2.3 and 0.41 mol m-2 yr-1, respectively, the annual air-sea uptake of
atmospheric CO2 is 4.4 mol m-2 yr-1, and the net annual flux due to biological
activity is calculated to 5.5 mol C m-2 yr-1, and 0.37 mol N m-2 yr-1. We also
deduce seasonal NCP by summing up the months with a positive drawdown of DIC,
and similar for new production by summing up the months with positive nitrate
drawdown. We quantify these to 5.6 mol C m-2 yr-1, and 0.51 mol N m-2 yr-1,
which gives a ratio markedly higher than Redfield. Results for phosphate and silicate
are also shown and discussed, as are the stoichiometry of the all deduced fluxes. |
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