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| Titel |
Seasonally Variable Cross-Slope Exchange in the Bay of Biscay Slope Current |
| VerfasserIn |
Marie Porter, Mark Inall, Mattias Green, John Simpson, Andrew Dale |
| 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 |
250075581
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| Zusammenfassung |
| Evidence is presented of topographically driven, cross-slope exchange in a seasonally reversed shelf slope current in the Bay of Biscay. In mid-June 2012, 20 satellite tracked drifting buoys, drogued at 50 m, were deployed across the shelf break in the southern Celtic Sea. Soon after deployment all of the drifters turned south, traveling parallel to the shelf break, into the Bay of Biscay. This slope-parallel, equator-ward flow continued throughout June and July, interrupted only when the current interacted with canyons in the shelf edge. These interactions lead to cross-slope transport. The apparent dependence on topography has resulted in the identification of key regions of on shelf transport between 45.5°N and 46.5°N.
From August until the end of the experiment, in December, the drifters that remained active turned to travel pole-ward. By September a slope-parallel, pole-ward flow had fully formed, with little evidence of cross-slope transport; corroborating previous suggestions of a seasonally reversing slope current. However, it appears that the formation of a pole-ward current occurred earlier in 2012 than suggested by previous studies. High storm activity during the summer of 2012 may have caused an earlier than usual return to winter conditions for the Bay of Biscay region.
Key regions of mass transport from above the abyssal plain and onto the European Shelf in the Bay of Biscay appear to be dependent on the topographical irregularities of the shelf. This cross slope exchange seems to be modified by the direction of the slope current. Thus, it is suggested that the topography and the local meteorology are key determinants of cross-slope transport of passive tracers in this region. |
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