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| Titel |
First-year sea ice melt pond fraction estimation from dual-polarisation C-band SAR – Part 2: Scaling in situ to Radarsat-2 |
| VerfasserIn |
R. K. Scharien, K. Hochheim, J. Landy, D. G. Barber |
| 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 ; 8, no. 6 ; Nr. 8, no. 6 (2014-11-25), S.2163-2176 |
| Datensatznummer |
250116382
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| Publikation (Nr.) |
 copernicus.org/tc-8-2163-2014.pdf |
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| Zusammenfassung |
| Sea ice melt pond fraction (fp), linked with lower sea ice surface
albedo and increased light transmittance to the ocean, is inadequately
parameterised in sea ice models due to a lack of observations. In this
paper, results from a multi-scale remote-sensing program dedicated to the
retrieval of level first-year sea ice (FYI) fp from dual co- and
cross-polarisation C-band synthetic aperture radar (SAR) backscatter are
detailed. Models which utilise the dominant effect of free-water
melt ponds on the VV / HH (vertical transmit and vertical receive / horizontal transmit and horizontal receive) polarisation ratio at high incidence angles are
tested for their ability to provide estimates of the subscale fp.
Retrieved fp from noise-corrected Radarsat-2 quad-polarisation scenes
are in good agreement with observations from coincident aerial survey data,
with root mean square errors (RMSEs) of 0.05–0.07 obtained during
intermediate and late stages of ponding. Weak model performance is
attributed to the presence of wet snow and slush during initial ponding, and
a synoptically driven freezing event causing ice lids to form on ponds. The
HV / HH (horizontal transmit and vertical receive / horizontal transmit and horizontal receive) ratio explains a greater portion of variability in fp, compared to
VV / HH, when ice lids are present. Generally low HV channel intensity
suggests limited applications using dual cross-polarisation data, except
with systems that have exceptionally low noise floors. Results demonstrate
the overall potential of dual-polarisation SAR for standalone or
complementary observations of fp for process-scale studies and
improvements to model parameterisations. |
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