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| Titel |
Pathways of upwelling deep waters to the surface of the Southern Ocean |
| VerfasserIn |
Veronica Tamsitt, Henri Drake, Adele Morrison, Lynne Talley, Carolina Dufour, Alison Gray, Stephen Griffies, Matthew Mazloff, Jorge Sarmiento, Jinbo Wang, Wilbert Weijer |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250146905
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| Publikation (Nr.) |
 EGU/EGU2017-10971.pdf |
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| Zusammenfassung |
| Upwelling of Atlantic, Indian and Pacific deep waters to the sea surface in the Southern
Ocean closes the global overturning circulation and is fundamentally important for oceanic
uptake of anthropogenic carbon and heat, nutrient resupply for sustaining oceanic biological
production, and the melt rate of ice shelves. Here we go beyond the two-dimensional
view of Southern Ocean upwelling, to show detailed Southern Ocean upwelling
pathways in three dimensions, using hydrographic observations and particle tracking in
high-resolution ocean and climate models. The northern deep waters enter the Antarctic
Circumpolar Current (ACC) via narrow southward currents along the boundaries of the
three ocean basins, before spiraling southeastward and upward through the ACC.
Upwelling is greatly enhanced at five major topographic features, associated with
vigorous mesoscale eddy activity. Deep water reaches the upper ocean predominantly
south of the southern ACC boundary, with a spatially nonuniform distribution,
regionalizing warm water supply to Antarctic ice shelves and the delivery of nutrient and
carbon-rich water to the sea surface. The timescale for half of the deep water to upwell
from 30°S to the mixed layer is on the order of 60-90 years, which has important
implications for the timescale for signals to propagate through the deep ocean.
In addition, we quantify the diabatic transformation along particle trajectories, to
identify where diabatic processes are important along the upwelling pathways. |
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