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| Titel |
A decade (2002-2012) of supraglacial lake volume estimates across Russell Glacier, West Greenland |
| VerfasserIn |
A. A. W. Fitzpatrick, A. L. Hubbard, J. E. Box, D. J. Quincey, D. Van As, A. P. B. Mikkelsen, S. H. Doyle, C. F. Dow, B. Hasholt, G. A. Jones |
| 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. 1 ; Nr. 8, no. 1 (2014-01-14), S.107-121 |
| Datensatznummer |
250116009
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| Publikation (Nr.) |
 copernicus.org/tc-8-107-2014.pdf |
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| Zusammenfassung |
| Supraglacial lakes represent an ephemeral storage buffer for meltwater runoff
and lead to significant, yet short-lived, episodes of ice-flow acceleration
by decanting large meltwater and energy fluxes into the ice sheet's
hydrological system. Here, a methodology for calculating lake volume is used
to quantify storage and drainage across Russell Glacier, West
Greenland, between 2002 and 2012. Using 502 MODIS scenes, water
volume at ~200 seasonally occurring lakes was derived using a
depth–reflectance relationship, which was independently calibrated and field
validated against lake bathymetry. The inland expansion of lakes is strongly
correlated with air temperature: during the record melt years of 2010 and
2012, lakes formed and drained earlier, attaining their maximum volume 38 and
20 days earlier than the 11 yr mean, as well as occupying a greater area and
forming at higher elevations (> 1800 m) than previously.
Despite occupying under 2% of the study area, lakes delay the
transmission of up to 7–13% of the bulk meltwater discharged.
Although the results are subject to an observational bias caused by periods
of cloud cover, we estimate that across Russell Glacier, 28% of
supraglacial lakes drain rapidly (< 4 days). Clustering of such
events in space and time suggests a synoptic trigger mechanism. Further, we
find no evidence to support a unifying critical size or depth-dependent
drainage threshold. |
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