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| Titel |
Recent extreme light sea ice years in the Canadian Arctic Archipelago: 2011 and 2012 eclipse 1998 and 2007 |
| VerfasserIn |
S. E. L. Howell, T. Wohlleben, A. Komarov, L. Pizzolato, C. Derksen |
| 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. 6 ; Nr. 7, no. 6 (2013-11-15), S.1753-1768 |
| Datensatznummer |
250085181
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| Publikation (Nr.) |
 copernicus.org/tc-7-1753-2013.pdf |
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| Zusammenfassung |
| Remarkably low mean September sea ice area in the Canadian Arctic Archipelago
(CAA) was observed in 2011 (146 × 103 km2), a
record-breaking level that was nearly exceeded in 2012
(150 × 103 km2). These values were lower than previous
September records set in 1998 (200 × 103 km2) and 2007
(220 × 103 km2), and are ∼60% lower than the
1981–2010 mean September climatology. In this study, the processes
contributing to the extreme light years of 2011 and 2012 were investigated,
compared to previous extreme minima of 1998 and 2007, and contrasted against
historic summer seasons with above average September ice area. The 2011
minimum was associated with positive June through September (JJAS) surface
air temperature (SAT) and net solar radiation (K*) anomalies that
facilitated rapid melt, coupled with atmospheric circulation that restricted
multi-year ice (MYI) inflow from the Arctic Ocean into the CAA. The 2012
minimum was also associated with positive JJAS SAT and K* anomalies with
coincident rapid melt, but further ice decline was temporarily mitigated by
atmospheric circulation which drove Arctic Ocean MYI inflow into the CAA.
Atmospheric circulation was comparable between 2011 and 1998 (impeding Arctic
Ocean MYI inflow) and 2012 and 2007 (inducing Arctic Ocean MYI inflow).
However, preconditioning was more apparent leading up to 2011 and 2012 than
1998 and 2007. The rapid melt process in 2011 and 2012 was more intense than
observed in 1998 and 2007 because of the thinner ice cover being more
susceptible to anomalous thermodynamic forcing. The thinner sea ice cover
within the CAA in recent years has also helped counteract the processes that
facilitate extreme heavy ice years. The recent extreme light years within the
CAA are associated with a longer navigation season within the Northwest
Passage. |
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