Cold-to-warm flow regime transition in snow avalanches

• Published in: The Cryosphere
• Main Authors: A. Köhler, J.-T. Fischer, R. Scandroglio, M. Bavay, J. McElwaine, B. Sovilla
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2018
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-12-3759-2018; https://doaj.org/article/e3496861ad9e422fb7f8a44bb2a5b70b

Large avalanches usually encounter different snow conditions along their track. When they release as slab avalanches comprising cold snow, they can subsequently develop into powder snow avalanches entraining snow as they move down the mountain. Typically, this entrained snow will be cold ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mover accent="true"><mi>T</mi><mo mathvariant="normal">‾</mo></mover><mo><</mo><mo>-</mo><mn mathvariant="normal">1</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="35pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="c061c33e1332134bcc44ddd2fb44f3ee"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-12-3759-2018-ie00001.svg" width="35pt" height="13pt" src="tc-12-3759-2018-ie00001.png"/></svg:svg> ∘ C) at high elevations near the surface, but warm ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><mover accent="true"><mi>T</mi><mo mathvariant="normal">‾</mo></mover><mo>></mo><mo>-</mo><mn mathvariant="normal">1</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="35pt" height="13pt" class="svg-formula" dspmath="mathimg" md5hash="a42e9edec11b50e6d83c96975babeadb"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-12-3759-2018-ie00002.svg" width="35pt" height="13pt" src="tc-12-3759-2018-ie00002.png"/></svg:svg> ∘ C) at lower elevations or deeper in the snowpack. The intake of warm snow is believed to be of major importance to increase the temperature of the snow composition in the avalanche and eventually cause a flow regime transition. Measurements of flow regime transitions are performed at the Vallée de la Sionne ...