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Titel |
Seasonal and interannual variability of physical and biological dynamics at the shelfbreak front of the Middle Atlantic Bight: nutrient supply mechanisms |
VerfasserIn |
R. He, K. Chen, K. Fennel, G. G. Gawarkiewicz, D. J. McGillicuddy Jr |
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. 10 ; Nr. 8, no. 10 (2011-10-20), S.2935-2946 |
Datensatznummer |
250006164
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Publikation (Nr.) |
copernicus.org/bg-8-2935-2011.pdf |
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Zusammenfassung |
A high-resolution, 3-dimensional coupled biophysical model is used to
simulate ocean circulation and ecosystem variations at the shelfbreak front
of the Middle Atlantic Bight (MAB). Favorable comparisons between satellite
observations and model hindcast solutions from January 2004 to November 2007
indicate the model has intrinsic skills in resolving fundamental physical
and biological dynamics at the MAB shelfbreak. Seasonal and interannual
variability of ocean physical and biological states and their driving
mechanisms are further analyzed. The domain-wide upper water column nutrient
content is found to peak in late winter-early spring. Phytoplankton spring
bloom starts 1–2 months later, followed by zooplankton bloom in early
summer. Our analysis shows the variability of shelfbreak nutrient supply is
controlled by local mixing that deepens the mixed layer and injects deep
ocean nutrients into the upper water column and alongshore nutrient
transport by the shelfbreak jet and associated currents. Nutrient vertical
advection associated with the shelfbreak bottom boundary layer convergence
is another significant contributor. Spring mean nutrient budget diagnostics
along the Nantucket transect are compared between nutrient rich 2004 and
nutrient poor 2007. Physical advection and diffusion play the major role in
determining strong interannual variations in shelfbreak nutrient content.
The biological (source minus sink) term is very similar between these two
years. |
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