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| Titel |
Empirical estimation of present-day Antarctic glacial isostatic adjustment and ice mass change |
| VerfasserIn |
B. C. Gunter, O. Didova, R. E. M. Riva, S. R. M. Ligtenberg, J. T. M. Lenaerts, M. A. King, M. R. van den Broeke, T. Urban |
| 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. 2 ; Nr. 8, no. 2 (2014-04-28), S.743-760 |
| Datensatznummer |
250116098
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| Publikation (Nr.) |
 copernicus.org/tc-8-743-2014.pdf |
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| Zusammenfassung |
| This study explores an approach that simultaneously estimates Antarctic mass
balance and glacial isostatic adjustment (GIA) through the combination of
satellite gravity and altimetry data sets. The results improve upon previous
efforts by incorporating a firn densification model to account for firn
compaction and surface processes as well as reprocessed data sets over a
slightly longer period of time. A range of different Gravity Recovery and Climate Experiment (GRACE) gravity models
were evaluated and a new Ice, Cloud, and Land Elevation Satellite (ICESat) surface height trend map computed
using an overlapping footprint approach. When the GIA models created from the
combination approach were compared to in situ GPS ground station
displacements, the vertical rates estimated showed consistently better
agreement than recent conventional GIA models. The new empirically derived
GIA rates suggest the presence of strong uplift in the Amundsen Sea sector in West Antarctica (WA) and the
Philippi/Denman sectors, as well as subsidence in large parts of East
Antarctica (EA). The total GIA-related mass change estimates for the entire
Antarctic ice sheet ranged from 53 to 103 Gt yr−1, depending on the GRACE
solution used, with an estimated uncertainty of ±40 Gt yr−1. Over the
time frame February 2003–October 2009, the corresponding ice mass change showed an
average value of −100 ± 44 Gt yr−1 (EA: 5 ± 38, WA: −105 ± 22),
consistent with other recent estimates in the literature, with regional mass
loss mostly concentrated in WA. The refined approach presented
in this study shows the contribution that such data combinations can make
towards improving estimates of present-day GIA and ice mass change,
particularly with respect to determining more reliable uncertainties. |
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