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| Titel |
Exchange of warming deep waters across Fram Strait |
| VerfasserIn |
Wilken-Jon von Appen, Ursula Schauer, Raquel Somavilla Cabrillo, Eduard Bauerfeind, Agnieszka Beszczynska-Moeller |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101755
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| Publikation (Nr.) |
 EGU/EGU2015-1969.pdf |
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| Zusammenfassung |
| Current meters measured temperature and velocity on 11Âmoorings from 1997 to 2014 in
Fram Strait between Svalbard and Greenland at the only deep passage from the Nordic Seas
to the Arctic Ocean. The sill depth in Fram Strait is 2545Âm. The observed temperatures vary
between the colder Greenland Sea Deep Water and the warmer Eurasian Basin Deep Water.
Both end members show a linear warming trend of 0.11±0.02°C/decade (GSDW) and
0.05±0.01°C/decade (EBDW) in agreement with the deep water warming observed in the
basins to the north and south. At the current warming rates, GSDW and EBDW will reach
the same temperature of -0.71°C in 2020. The deep water on the approximately
40 km wide plateau near the sill in Fram Strait is a mixture of the two end members
with both contributing similar amounts. This water mass is continuously formed by
mixing in Fram Strait and subsequently exported out of Fram Strait. Individual
measurements are approximately normally distributed around the average of the two end
members. Meridionally, the mixing is confined to the plateau region. Measurements less
than 20 km to the north and south have properties much closer to the properties
in the respective basins than to the mixed water on the plateau. The temperature
distribution around Fram Strait indicates that the mean flow cannot be responsible for
the deep water exchange across the sill. Rather, a coherence analysis shows that
mesoscale flows with periods of approximately 1–2Âweeks advect the water masses
across Fram Strait. These flows are barotropically forced by upper ocean mesoscale
variability. We conclude that these mesoscale flows make Fram Strait a hot spot of
deep water mixing in the Arctic Mediterranean. The fate of the mixed water is
not clear, but after the early 1990s, it does not reflect the properties of Norwegian
Sea Deep Water. We propose that it currently mostly fills the deep Greenland Sea. |
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