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Titel |
Spatially extensive estimates of annual accumulation in the dry snow zone of the Greenland Ice Sheet determined from radar altimetry |
VerfasserIn |
S. Peña, P. Nienow, A. Shepherd, V. Helm, D. Mair, E. Hanna, P. Huybrechts, Q. Guo, R. Cullen, D. Wingham |
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 ; 4, no. 4 ; Nr. 4, no. 4 (2010-11-02), S.467-474 |
Datensatznummer |
250001897
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Publikation (Nr.) |
copernicus.org/tc-4-467-2010.pdf |
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Zusammenfassung |
We present estimates of accumulation rate along a 200 km
transect ranging in elevation from 2750 to 3150 m in the dry snow zone on
the western slope of the Greenland Ice Sheet. An airborne radar altimeter is
used to estimate the thickness of annual internal layers and, in conjunction
with ground based snow/firn density profiles, annual accumulation rates
between 1998 and 2003 are derived. A clear gradient in the thickness of each
layer observed by the radar altimeter and in the associated estimates of
annual accumulation is seen along the transect, with a 33.6% ± 16%
mean decrease in accumulation from west to east. The observed inter-annual
variability is high, with the annual mean accumulation rate estimated at
0.359 m.w.e. yr−1 (s.d. ± 0.049 m.w.e. yr−1). Mean
accumulation rates modelled using meteorological models overestimate our
results by 16% on average, but by 32% and 42% in the years 2001 and
2002. The methodology presented here demonstrates the potential to obtain
accurate and spatially extensive accumulation rates from radar altimeters in
regions of ice sheets where field observations are sparse, and accumulation rates greater than several tens of cm. |
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