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| Titel |
CryoSat-2 delivers monthly and inter-annual surface elevation change for Arctic ice caps |
| VerfasserIn |
L. Gray, D. Burgess, L. Copland, M. N. Demuth, T. Dunse, K. Langley, T. V. Schuler |
| 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 ; 9, no. 5 ; Nr. 9, no. 5 (2015-09-25), S.1895-1913 |
| Datensatznummer |
250116855
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| Publikation (Nr.) |
 copernicus.org/tc-9-1895-2015.pdf |
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| Zusammenfassung |
| We show that the CryoSat-2 radar altimeter can provide useful estimates of
surface elevation change on a variety of Arctic ice caps, on both monthly
and yearly timescales. Changing conditions, however, can lead to a varying
bias between the elevation estimated from the radar altimeter and the
physical surface due to changes in the ratio of subsurface to surface
backscatter. Under melting conditions the radar returns are predominantly
from the surface so that if surface melt is extensive across the ice cap
estimates of summer elevation loss can be made with the frequent coverage
provided by CryoSat-2. For example, the average summer elevation decreases
on the Barnes Ice Cap, Baffin Island, Canada were 2.05 ± 0.36 m
(2011), 2.55 ± 0.32 m (2012), 1.38 ± 0.40 m (2013) and
1.44 ± 0.37 m (2014), losses which were not balanced by the winter snow
accumulation. As winter-to-winter conditions were similar, the net elevation
losses were 1.0 ± 0.20 m (winter 2010/11 to winter 2011/12),
1.39 ± 0.20 m (2011/12 to 2012/13) and 0.36 ± 0.20 m (2012/13 to
2013/14); for a total surface elevation loss of 2.75 ± 0.20 m over this
3-year period. In contrast, the uncertainty in height change from Devon Ice
Cap, Canada, and Austfonna, Svalbard, can be up to twice as large because of
the presence of firn and the possibility of a varying bias between the true
surface and the detected elevation due to changing year-to-year conditions.
Nevertheless, the surface elevation change estimates from CryoSat for both
ice caps are consistent with field and meteorological measurements. |
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