Item: ASSESSING CRITICAL WET-SNOW AVALANCHE SITUATIONS WITH SPATIALLY DISTRIBUTED SNOW COVER SIMULATIONS
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Title: ASSESSING CRITICAL WET-SNOW AVALANCHE SITUATIONS WITH SPATIALLY DISTRIBUTED SNOW COVER SIMULATIONS
Proceedings: International Snow Science Workshop 2024, Tromsø, Norway
Authors:
- Andrea Bruckmeier [ Department of Earth Sciences, Montana State University ] [ Department of Geography, University of Innsbruck ]
- Erwin Rottler [ Department of Geography, University of Innsbruck ]
- Michael Warscher [ Department of Geography, University of Innsbruck ]
- Ulrich Strasser [ Department of Geography, University of Innsbruck ]
- Christoph Mitterer [ Avalanche Warning Service Tyrol ]
Date: 2024-09-23
Abstract: In recent years, physics-based snow cover models have gained importance in supporting avalanche forecasting to better assess critical avalanche conditions. Latest approaches focused on helping and guiding the forecasters in the decision-making process on the most prominent parts describing avalanche danger: the avalanche danger level, snowpack stability or the prevailing avalanche problem. However, it is still challenging to directly link the prevailing avalanche problem (type) obtained from point simulations in a spatially distributed manner. This becomes even more pronounced for warning regions with large gradients in the meteorological variables and/or sparse weather station density. To overcome this issue, we complement simulations of the snow stratigraphy conducted at the point-scale with the 1-D snow cover model SNOWPACK, using openAMUNDSEN, an intermediate complexity and spatially distributed energy-balance-based snow cover model to assess critical wet-snow avalanche situations. This study focuses on a selected avalanche warning region located in the South-Eastern part of Tyrol in Austria (East Tyrol). First, we compare the temporal dynamics of simulated wet snow throughout a winter season using SNOWPACK and openAMUNDSEN at a weather station. Both are tested for a potential relation to days for which the Avalanche Warning Service Tyrol has issued the wet-snow avalanche problem. Next, exemplary examinations of the spatial distribution of the simulated LWCindex for days with rain-on-snow and snow melt as the underlying process leading to the wet-snow avalanche problem forecasted by the Avalanche Warning Service Tyrol indicate that openAMUNDSEN has the capability to capture the spatial variability of liquid water in snow depending on elevation and aspect. Satellite-based wet-snow maps from Sentinel-1 images proved to be valuable sources of information on the wet-snow extent in complex mountain terrain and can be used to evaluate model results. Our results indicate that the modelled spatial-temporal information on the liquid water in snow has the potential to support the detection and characterization of periods and areas being subject to the wet-snow avalanche problem. This study provides encouraging new insights that can be used in the further development of operational model applications to support the avalanche problem detection and forecasting.
Object ID: ISSW2024_O1.8.pdf
Language of Article: English
Presenter(s): Andrea Bruckmeier
Keywords: wet snow, openAMUNDSEN, SNOWPACK, liquid water content, avalanche problems, snow cover simulations
Page Number(s): 45 - 51
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