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| Titel |
A combined approach of remote sensing and airborne electromagnetics to determine the volume of polynya sea ice in the Laptev Sea |
| VerfasserIn |
L. Rabenstein, T. Krumpen, S. Hendricks, C. Koeberle, C. Haas, J. A. Hoelemann |
| 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. 3 ; Nr. 7, no. 3 (2013-06-19), S.947-959 |
| Datensatznummer |
250017978
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| Publikation (Nr.) |
 copernicus.org/tc-7-947-2013.pdf |
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| Zusammenfassung |
| A combined interpretation of synthetic aperture radar (SAR) satellite
images and helicopter electromagnetic (HEM) sea-ice thickness data has
provided an estimate of sea-ice volume formed in Laptev Sea polynyas
during the winter of 2007/08. The evolution of the surveyed sea-ice
areas, which were formed between late December 2007 and middle April
2008, was tracked using a series of SAR images with a sampling
interval of 2–3 days. Approximately 160 km of HEM data
recorded in April 2008 provided sea-ice thicknesses along profiles
that transected sea ice varying in age from 1 to 116 days. For the
volume estimates, thickness information along the HEM profiles was
extrapolated to zones of the same age. The error of areal mean
thickness information was estimated to be between 0.2 m for
younger ice and up to 1.55 m for older ice, with the primary
error source being the spatially limited HEM coverage. Our results
have demonstrated that the modal thicknesses and mean thicknesses of
level ice correlated with the sea-ice age, but that varying dynamic
and thermodynamic sea-ice growth conditions resulted in a rather
heterogeneous sea-ice thickness distribution on scales of tens of
kilometers. Taking all uncertainties into account, total sea-ice area
and volume produced within the entire surveyed area were 52 650 km2
and 93.6 ± 26.6 km3. The surveyed polynya contributed 2.0 ± 0.5% of the sea-ice produced throughout the Arctic during the
2007/08 winter. The SAR-HEM volume estimate compares well with the 112 km3
ice production calculated with a~high-resolution ocean
sea-ice model. Measured modal and mean-level ice thicknesses correlate
with calculated freezing-degree-day thicknesses with a factor of
0.87–0.89, which was too low to justify the assumption of homogeneous
thermodynamic growth conditions in the area, or indicates a strong
dynamic thickening of level ice by rafting of even thicker ice. |
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