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| Titel |
Tidally-induced dispersion of the Storfjorden overflow plume onto the West Svalbard Shelf |
| VerfasserIn |
Fred Wobus, Georgy I. Shapiro, John M. Huthnance, Miguel A. M. Maqueda, Yevgeny Aksenov |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250076196
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| Zusammenfassung |
| We investigate the flow of brine-enriched shelf water from the Storfjorden (Svalbard) into
Fram Strait and onto the Western Svalbard Shelf using NEMO, a 3D numerical ocean
circulation model, in a regional setup with realistic bathymetry, full meteorology, open
boundary conditions and tides. The model has 3 km horizontal resolution and 50 vertical
levels in the sh-coordinate system which is specially designed to resolve bottom boundary
layer processes.
In a series of experiments varying initial plume density and wind strength we focus on the
influence of the tides on the propagation of the dense water plume by turning on and off the
tidal forcing at the model boundaries.
Simulations including tides consistently reveal increased horizontal diffusivity around the
Sørkapp, the southernmost headland of Spitsbergen, which is in close proximity to the plume
path. Due to the tides and largely independent of wind effects the plume widens and laterally
disperses as it spreads into Storfjordrenna, the trough steering the plume’s path from the fjord
towards the continental slope. On the shallow shelf the tides also increase the vertical
diffusivity and thus plume height, with wind-driven turbulence contributing to this
effect.
We find that a tidally augmented exchange between the Svalbard Coastal Current and
lighter fractions of overflow water leads to their propagation onto the Western Svalbard Shelf
where water of Storfjorden origin may enter several large fjords. Based on our results from
the Storfjorden we conclude that tidal modulation during the shallow phase of the overflow
could also be important for other dense water cascades originating in shallow shelf
regions. |
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