Wind tunnel experiments: saltation is necessary for wind-packing

• Published in: Journal of Glaciology
• Main Authors: CHRISTIAN G. SOMMER, MICHAEL LEHNING, CHARLES FIERZ
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2017
• Subjects: snow; snow/ice surface processes; wind-blown snow; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Journal of Glaciology
• Online Access: https://doi.org/10.1017/jog.2017.53; https://doaj.org/article/c4016dd0d5f8427b900e8f216c8a1158

Wind-packed snow in the form of slabs or crusts is an important part of alpine and polar snow covers. Yet, the formation process of such layers is poorly understood. For example, it remains unclear whether drifting snow is necessary for wind-packing or not. A better understanding of wind-packing could improve snow-cover models and avalanche danger forecasts and contribute to the assessment of mass balances in polar regions. We designed a closed-circuit, obround wind tunnel to study the process of wind crust formation. A SnowMicroPen was used to measure how the hardness of the snow evolved. The results show that no crust forms without saltation. Drifting snow is a necessary but not sufficient condition for wind-packing. The dynamics of erosion and deposition appear to be equally important.