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| Titel |
Vertical profile of the specific surface area and density of the snow at Dome C and on a transect to Dumont D'Urville, Antarctica – albedo calculations and comparison to remote sensing products |
| VerfasserIn |
J.-C. Gallet, F. Domine, L. Arnaud, G. Picard, J. Savarino |
| 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 ; 5, no. 3 ; Nr. 5, no. 3 (2011-08-19), S.631-649 |
| Datensatznummer |
250002594
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| Publikation (Nr.) |
 copernicus.org/tc-5-631-2011.pdf |
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| Zusammenfassung |
| The specific surface area (SSA) of snow determines in part the albedo of
snow surfaces and the capacity of the snow to adsorb chemical species and
catalyze reactions. Despite these crucial roles, almost no value of snow SSA
are available for the largest permanent snow expanse on Earth, the
Antarctic. We report the first extensive study of vertical profiles of snow
SSA near Dome C (DC: 75°06' S, 123°20' E, 3233 m a.s.l.)
on the Antarctic plateau, and at seven sites during the logistical traverse between
Dome C and the French coastal base Dumont D'Urville (DDU: 66°40' S,
140°01' E) during the Austral summer 2008–2009. We used the DUFISSS
system, which measures the IR reflectance of snow at 1310 nm with an
integrating sphere. At DC, the mean SSA of the snow in the top 1 cm is 38 m2 kg−1,
decreasing monotonically to 14 m2 kg−1 at a
depth of 50 cm. Along the traverse, the snow SSA profile is similar to that
at DC in the first 600 km from DC. Closer to DDU, the SSA of the top 5 cm is
23 m2 kg−1, decreasing to 19 m2 kg−1 at 50 cm depth.
This difference is attributed to wind, which causes a rapid decrease of
surface snow SSA, but forms hard windpacks whose SSA decrease more slowly
with time. Since light-absorbing impurities are not concentrated enough to
affect albedo, the vertical profiles of SSA and density were used to
calculate the spectral albedo of the snow for several realistic illumination
conditions, using the DISORT radiative transfer model. A preliminary
comparison with MODIS data is presented and our calculations and MODIS data
show similar trends. |
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