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| Titel |
Density assumptions for converting geodetic glacier volume change to mass change |
| VerfasserIn |
M. Huss |
| 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 ; 7, no. 3 ; Nr. 7, no. 3 (2013-05-27), S.877-887 |
| Datensatznummer |
250017972
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| Publikation (Nr.) |
 copernicus.org/tc-7-877-2013.pdf |
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| Zusammenfassung |
| The geodetic method is widely used for assessing changes in the
mass balance of mountain glaciers. However, comparison of
repeated digital elevation models only provides a glacier volume
change that must be converted to a change in mass using
a density assumption or model. This study investigates the use
of a constant factor for the volume-to-mass conversion based on
a firn compaction model applied to simplified glacier geometries
with idealized climate forcing, and two glaciers with long-term
mass balance series. It is shown that the "density" of
geodetic volume change is not a constant factor and is
systematically smaller than ice density in most cases. This is
explained by the accretion/removal of low-density firn layers,
and changes in the firn density profile with positive/negative
mass balance. Assuming a value of 850 ± 60 kg m−3
to convert volume change to mass change is appropriate for
a wide range of conditions. For short time intervals
(≤3 yr), periods with limited volume change,
and/or changing mass balance gradients, the conversion factor
can however vary from 0–2000 kg m−3 and beyond,
which requires caution when interpreting glacier mass changes
based on geodetic surveys. |
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