MoT-PSA: a two-layer depth-averaged model for simulation of powder snow avalanches on 3-D terrain

For snow-avalanche hazard mapping, one needs efficient tools that nevertheless capture the essential physical processes. The code MoT-PSA (Method of Transport – Powder Snow Avalanche) described here is based on the two-layer depth-averaged formulation for mixed snow avalanches developed by Eglit and...

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Main Authors: Hervé Vicari, Dieter Issler
Format: Article
Language:English
Published: Cambridge University Press 2025-01-01
Series:Annals of Glaciology
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Online Access:https://www.cambridge.org/core/product/identifier/S0260305524000107/type/journal_article
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author Hervé Vicari
Dieter Issler
author_facet Hervé Vicari
Dieter Issler
author_sort Hervé Vicari
collection DOAJ
description For snow-avalanche hazard mapping, one needs efficient tools that nevertheless capture the essential physical processes. The code MoT-PSA (Method of Transport – Powder Snow Avalanche) described here is based on the two-layer depth-averaged formulation for mixed snow avalanches developed by Eglit and co-workers in the 1980s but is extended to 3-D terrain and uses a fast numerical scheme based on the method of transport. Compared to previous works, we introduce novel formulations for the suspension and deposition of snow from the dense core. Snow cover and air entrainment are quantified with physics-based models. A sensitivity study of the model parameters on an idealized topography shows that both the dense core and the parameters of the powder snow cloud (PSC) governing particle suspension and settling significantly affect the dynamics. As expected, we observe that snow cover entrainment favours the formation of large PSCs with long runout. The powder-snow avalanche that occurred in Lom (Norway) on 27 February 2020 is back-calculated using MoT-PSA. With plausible parameter values, the model reproduces the dense core stopping at the gully's base and the dilute PSC travelling across the frozen lake for almost 1 km.
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issn 0260-3055
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publishDate 2025-01-01
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series Annals of Glaciology
spelling doaj-art-e940dbf6185441cbbdb2b37aa117fcaf2025-08-20T02:15:46ZengCambridge University PressAnnals of Glaciology0260-30551727-56442025-01-016510.1017/aog.2024.10MoT-PSA: a two-layer depth-averaged model for simulation of powder snow avalanches on 3-D terrainHervé Vicari0https://orcid.org/0000-0001-5970-7359Dieter Issler1https://orcid.org/0000-0003-2151-2331Natural Hazards Division, Norwegian Geotechnical Institute, P.O. Box 3930 Ullevål Stadion, 0806 Oslo, Norway WSL Institute for Snow and Avalanche Research SLF, CH-7260 Davos Dorf, Switzerland Climate Change, Extremes, and Natural Hazards in Alpine Regions Research Center CERC, CH-7260 Davos Dorf, SwitzerlandNatural Hazards Division, Norwegian Geotechnical Institute, P.O. Box 3930 Ullevål Stadion, 0806 Oslo, NorwayFor snow-avalanche hazard mapping, one needs efficient tools that nevertheless capture the essential physical processes. The code MoT-PSA (Method of Transport – Powder Snow Avalanche) described here is based on the two-layer depth-averaged formulation for mixed snow avalanches developed by Eglit and co-workers in the 1980s but is extended to 3-D terrain and uses a fast numerical scheme based on the method of transport. Compared to previous works, we introduce novel formulations for the suspension and deposition of snow from the dense core. Snow cover and air entrainment are quantified with physics-based models. A sensitivity study of the model parameters on an idealized topography shows that both the dense core and the parameters of the powder snow cloud (PSC) governing particle suspension and settling significantly affect the dynamics. As expected, we observe that snow cover entrainment favours the formation of large PSCs with long runout. The powder-snow avalanche that occurred in Lom (Norway) on 27 February 2020 is back-calculated using MoT-PSA. With plausible parameter values, the model reproduces the dense core stopping at the gully's base and the dilute PSC travelling across the frozen lake for almost 1 km.https://www.cambridge.org/core/product/identifier/S0260305524000107/type/journal_articledepositiondepth-averaged numerical modellingentrainmenthazard mappingimpact pressuremixed snow avalanchesuspension layertwo layers
spellingShingle Hervé Vicari
Dieter Issler
MoT-PSA: a two-layer depth-averaged model for simulation of powder snow avalanches on 3-D terrain
Annals of Glaciology
deposition
depth-averaged numerical modelling
entrainment
hazard mapping
impact pressure
mixed snow avalanche
suspension layer
two layers
title MoT-PSA: a two-layer depth-averaged model for simulation of powder snow avalanches on 3-D terrain
title_full MoT-PSA: a two-layer depth-averaged model for simulation of powder snow avalanches on 3-D terrain
title_fullStr MoT-PSA: a two-layer depth-averaged model for simulation of powder snow avalanches on 3-D terrain
title_full_unstemmed MoT-PSA: a two-layer depth-averaged model for simulation of powder snow avalanches on 3-D terrain
title_short MoT-PSA: a two-layer depth-averaged model for simulation of powder snow avalanches on 3-D terrain
title_sort mot psa a two layer depth averaged model for simulation of powder snow avalanches on 3 d terrain
topic deposition
depth-averaged numerical modelling
entrainment
hazard mapping
impact pressure
mixed snow avalanche
suspension layer
two layers
url https://www.cambridge.org/core/product/identifier/S0260305524000107/type/journal_article
work_keys_str_mv AT hervevicari motpsaatwolayerdepthaveragedmodelforsimulationofpowdersnowavalancheson3dterrain
AT dieterissler motpsaatwolayerdepthaveragedmodelforsimulationofpowdersnowavalancheson3dterrain