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| Titel |
Point observations of liquid water content in wet snow – investigating methodical, spatial and temporal aspects |
| VerfasserIn |
F. Techel, C. Pielmeier |
| 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 ; 5, no. 2 ; Nr. 5, no. 2 (2011-05-18), S.405-418 |
| Datensatznummer |
250002432
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| Publikation (Nr.) |
 copernicus.org/tc-5-405-2011.pdf |
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| Zusammenfassung |
| Information about the volume and the spatial and temporal distribution of liquid
water in snow is important for forecasting wet snow avalanches and for predicting melt-water run-off.
The distribution of liquid water in snow is commonly estimated from point measurements using a "hand" squeeze test,
or a dielectric device such as a "Snow Fork" or a "Denoth meter". Here we
compare estimates of water content in the Swiss Alps made using the hand test
to those made with a Snow Fork and a Denoth meter. Measurements were conducted
in the Swiss Alps, mostly above tree line; more than 12 000 measurements were
made at 85 locations over 30 days. Results show that the hand test generally
over estimates the volumetric liquid water content. Estimates using the Snow
Fork are generally 1 % higher than those derived from the Denoth meter. The
measurements were also used to investigate temporal and small-scale spatial patterns
of wetness. Results show that typically a single point measurement does not characterize
the wetness of the surrounding snow. Large diurnal changes in wetness are common in
the near-surface snow, and associated changes at depth were also observed. A single
vertical profile of measurements is not sufficient to determine whether these
changes were a result of a spatially homogeneous wetting front or caused by
infiltration through pipes. Based on our observations, we suggest that three
measurements at horizontal distances greater than 50 cm are needed to adequately characterize
the distribution of liquid water through a snowpack. Further, we suggest a simplified
classification scheme that includes five wetness patterns that incorporate both the
vertical and horizontal distribution of liquid water in a snowpack. |
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