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| Titel |
Importance of dissolved organic nitrogen in the north Atlantic Ocean in sustaining primary production: a 3-D modelling approach |
| VerfasserIn |
G. Charria, I. Dadou, J. Llido, M. Drévillon, V. Garçon |
| 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 ; 5, no. 5 ; Nr. 5, no. 5 (2008-10-27), S.1437-1455 |
| Datensatznummer |
250002838
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| Publikation (Nr.) |
 copernicus.org/bg-5-1437-2008.pdf |
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| Zusammenfassung |
An eddy-permitting coupled ecosystem-circulation model including dissolved
organic matter is used to estimate the dissolved organic nitrogen (DON)
supply sustaining primary production in the subtropical north Atlantic Ocean.
After an analysis of the coupled model performances compared to the data, a
sensitivity study demonstrates the strong impact of parameter values linked
to the hydrolysis of particulate organic nitrogen and remineralisation of
dissolved organic nitrogen on surface biogeochemical concentrations.
The physical transport of dissolved organic nitrogen contributes to maintain
the level of primary production in this subtropical gyre. It is dominated by
the meridional component. We estimate a meridional net input of
0.039 molN m−2 yr−1 over the domain (13–35° N and
71–40° W) in the subtropical gyre. This supply is driven by the
Ekman transport in the southern part and by non-Ekman transport (meridional
current components, eddies, meanders and fronts) in the northern part of the
subtropical gyre. At 12° N, our estimate (18 kmolN s−1)
confirms the estimation (17.9 kmolN s−1) made by Roussenov et
al. (2006) using a simplified biogeochemical model in a large scale model.
This DON meridional input is within the range (from 0.05 up to
0.24 molN m−2 yr−1) (McGillicuddy and Robinson, 1997; Oschlies,
2002) of all other possible mechanisms (mesoscale activity, nitrogen
fixation, atmospheric deposition) fuelling primary production in the
subtropical gyre. The present study confirms that the lateral supply of
dissolved organic nitrogen might be important in closing the N budget over
the north Atlantic Ocean and quantifies the importance of meridional input of
dissolved organic nitrogen. |
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