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Titel |
Recent summer Arctic atmospheric circulation anomalies in a historical perspective |
VerfasserIn |
A. Belleflamme, X. Fettweis, M. Erpicum |
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 ; 9, no. 1 ; Nr. 9, no. 1 (2015-01-07), S.53-64 |
Datensatznummer |
250116735
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Publikation (Nr.) |
copernicus.org/tc-9-53-2015.pdf |
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Zusammenfassung |
A significant increase in the summertime occurrence of a high pressure area
over the Beaufort Sea, the Canadian Arctic Archipelago, and Greenland has
been observed since the beginning of the 2000s, and particularly between 2007
and 2012. These circulation anomalies are likely partly responsible for the
enhanced Greenland ice sheet melt as well as the Arctic sea ice loss observed
since 2007. Therefore, it is interesting to analyse whether similar
conditions might have happened since the late 19th century over the Arctic
region. We have used an atmospheric circulation type classification based on
daily mean sea level pressure and 500 hPa geopotential height data from five
reanalysis data sets (ERA-Interim, ERA-40, NCEP/NCAR, ERA-20C, and 20CRv2) to
put the recent circulation anomalies in perspective with the atmospheric
circulation variability since 1871. We found that circulation conditions
similar to 2007–2012 have occurred in the past, despite a higher uncertainty
of the reconstructed circulation before 1940. For example, only ERA-20C shows
circulation anomalies that could explain the 1920–1930 summertime Greenland
warming, in contrast to 20CRv2. While the recent anomalies exceed by a factor
of 2 the interannual variability of the atmospheric circulation of the
Arctic region, their origin (natural variability or global warming) remains
debatable. |
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