Wet snow pendular regime: the amount of water in ring-shaped configurations

Authors
Citation
A. Denoth, Wet snow pendular regime: the amount of water in ring-shaped configurations, COLD REG SC, 30(1-3), 1999, pp. 13-18
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Civil Engineering
Journal title
COLD REGIONS SCIENCE AND TECHNOLOGY
ISSN journal
0165-232X → ACNP
Volume
30
Issue
1-3
Year of publication
1999
Pages
13 - 18
Database
ISI
SICI code
0165-232X(199912)30:1-3<13:WSPRTA>2.0.ZU;2-H
Abstract
The water saturation of a natural snow cover varies, in general, from zero to approximately 20% of the pore volume, whereby two essentially different types of water geometry-pendular mode and funicular mode-can be observed. T he pendular mode covers the low-saturation range (typically S less than or equal to 7% for old coarse grained Alpine snow) and most of the water is pr obably contained in veins; in the case that the snow has experienced freeze -thaw cycles, the water component may be arranged in isolated menisci or pe ndular rings around a contact zone between spheroidal ice grains. However, the water rings or menisci are, thermodynamically, in a very critical-may b e in an unstable-configuration. As water rings or menisci represent closed electrically conducting loops, they may be responsible for an induced diama gnetic behaviour of snow, especially in the microwave regime; and this offe rs a way to measure the amount of water stored in this geometrical configur ation. From a careful analysis of the measured dielectric and magnetic perm eability in the microwave C- to K-bands of moderate wet coarse grained Alpi ne snow results, water rings seem only to exist at saturations lower than a pproximate to 8%. For saturations exceeding this critical value, water ring s begin to merge forming clusters, whereby the number of ring-like geometri es decreases in favor of larger but open-ended structures. (C) 1999 Elsevie r Science B.V. All rights reserved.