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Titel |
Time-evolving mass loss of the Greenland Ice Sheet from satellite altimetry |
VerfasserIn |
R. T. W. L. Hurkmans, J. L. Bamber, C. H. Davis, I. R. Joughin, K. S. Khvorostovsky, B. S. Smith, N. Schoen |
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. 5 ; Nr. 8, no. 5 (2014-09-17), S.1725-1740 |
Datensatznummer |
250116315
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Publikation (Nr.) |
copernicus.org/tc-8-1725-2014.pdf |
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Zusammenfassung |
Mass changes of the Greenland Ice Sheet may be estimated by the input–output
method (IOM), satellite gravimetry, or via surface elevation change rates
(dH/dt). Whereas the first two have been shown to agree well in
reconstructing ice-sheet wide mass changes over the last decade, there are
few decadal estimates from satellite altimetry and none that provide a
time-evolving trend that can be readily compared with the other methods.
Here, we interpolate radar and laser altimetry data between 1995 and 2009 in
both space and time to reconstruct the evolving volume changes. A firn
densification model forced by the output of a regional climate model is used
to convert volume to mass. We consider and investigate the potential sources
of error in our reconstruction of mass trends, including geophysical biases
in the altimetry, and the resulting mass change rates are compared to other
published estimates. We find that mass changes are dominated by surface mass
balance (SMB) until about 2001, when mass loss rapidly accelerates. The onset
of this acceleration is somewhat later, and less gradual, compared to the
IOM. Our time-averaged mass changes agree well with recently published
estimates based on gravimetry, IOM, laser altimetry, and with radar altimetry
when merged with airborne data over outlet glaciers. We demonstrate that,
with appropriate treatment, satellite radar altimetry can provide reliable
estimates of mass trends for the Greenland Ice Sheet. With the inclusion of
data from CryoSat-2, this provides the possibility of producing a continuous
time series of regional mass trends from 1992 onward. |
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