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| Titel |
Variability and trends in Laptev Sea ice outflow between 1992–2011 |
| VerfasserIn |
T. Krumpen, M. Janout, K. I. Hodges, R. Gerdes, F. Girard-Ardhuin, J. A. Hölemann, S. Willmes |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 7, no. 1 ; Nr. 7, no. 1 (2013-02-28), S.349-363 |
| Datensatznummer |
250017935
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| Publikation (Nr.) |
 copernicus.org/tc-7-349-2013.pdf |
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| Zusammenfassung |
| Variability and trends in seasonal and interannual ice area export
out of the Laptev Sea between 1992 and 2011 are investigated using
satellite-based sea ice drift and concentration data. We found an average
total winter (October to May) ice area transport across the northern and
eastern Laptev Sea boundaries (NB and EB) of
3.48 × 105 km2. The average transport across the NB
(2.87 × 105 km2) is thereby higher than across the EB
(0.61 × 105 km2), with a less pronounced seasonal cycle.
The total Laptev Sea ice area flux significantly increased over the last
decades (0.85 × 105 km2 decade−1, p > 0.95),
dominated by increasing export through the EB (0.55 × 105
km2 decade−1, p
> 0.90), while the increase in export across the NB is smaller
(0.3 × 105 km2 decade−1) and statistically not
significant. The strong coupling between across-boundary SLP gradient and ice
drift velocity indicates that monthly variations in ice area flux are
primarily controlled by changes in geostrophic wind velocities, although the
Laptev Sea ice circulation shows no clear relationship with large-scale
atmospheric indices. Also there is no evidence of increasing wind velocities
that could explain the overall positive trends in ice export. The increased
transport rates are rather the consequence of a changing ice cover such as
thinning and/or a decrease in concentration. The use of a back-propagation
method revealed that most of the ice that is incorporated into the Transpolar
Drift is formed during freeze-up and originates from the central and western
part of the Laptev Sea, while the exchange with the East Siberian Sea is
dominated by ice coming from the central and southeastern Laptev Sea.
Furthermore, our results imply that years of high ice export in late winter
(February to May) have a thinning effect on the ice cover, which in turn
preconditions the occurence of negative sea ice extent anomalies in summer. |
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