Item: THE FORMATION OF BASAL LIQUID-WATER LAYERS IN EARLY-WINTER ("COLD") GLIDE-SNOW AVALANCHES
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Title: THE FORMATION OF BASAL LIQUID-WATER LAYERS IN EARLY-WINTER ("COLD") GLIDE-SNOW AVALANCHES
Proceedings: International Snow Science Workshop Proceedings 2023, Bend, Oregon
Authors:
- Michael Lombardo [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Amelie Fees [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Peter Lehmann [ Physics of Soils and Terrestrial Ecosystems, ETH Zurich, Zurich, Switzerland ]
- Alec van Herwijnen [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Juerg Schweizer [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
Date: 2023-10-08
Abstract: A liquid water layer in the basal snowpack is considered one of the critical requirements for glide-snow avalanche release. However, the processes leading to this liquid water formation are not well understood. This is particularly true for so-called "cold" events, which tend to occur in winter without percolation of water from the snow surface. For these cold events, the liquid water is thought to form due to capillary suction from the soil into the snow and/or from melting of the basal snowpack due to the warm ground. Here, we use theoretical calculations and the 1D-model SNOWPACK, to investigate the interplay of capillary and thermal processes during the formation of basal liquid water layers in cold glide-snow avalanche events. Two early-winter glide-snow avalanches observed at the Dorfberg (Davos, Switzerland) field site are analyzed. For these events, melting was responsible for the basal liquid water layers as capillary rise was not expected based on the conditions within the soil. Application of this model to larger glide-snow avalanche datasets will further improve our understanding of this basal liquid-water layer, its formation, and the critical thresholds relevant for predicting cold glide-snow avalanche release.
Object ID: ISSW2023_P1.56.pdf
Language of Article: English
Presenter(s): Michael Lombardo
Keywords: glide-snow avalanche, liquid water content, avalanche formation
Page Number(s): 463 - 466
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