Wind and snow particle distribution in powder snow cloud

Y. Ito (1) , K. Nishimura (1) , F. Naaim-Bouvet (2) , H. Bellot (2) , X. Ravanat (2) , Emmanuel Thibert (2)

1 aucun
2 UR ETGR (ETNA) - Erosion torrentielle neige et avalanches

An ultrasonic anemometer and a snow particle counter were newly installed in the avalanche test site locating at the Col du Lautaret pass, France. Simultaneous measurements of both wind and snow particles in the powder snow cloud were made to investigate the powder part of the avalanche in 2013 winter. The particle speed and diameter were calculated from the high-frequency recording of direct SPC output. The particle speed showed lower values than the wind speed. Relatively large particles were observed around the avalanche front and the size of the particles was slightly decreased in the following flow. The particle size distribution was well estimated by the aerodynamic theory except around the avalanche front.

Mots clés: AVALANCHE POUDREUSE; NEIGE AEROSOL; TRANSPORT DE NEIGE PAR LE VENT; GRAIN DE NEIGE; AVALANCHE; POWDER SNOW CLOUD; WIND SPEED; PARTICLE SIZE

Domaines: Sciences de l'environnement

Y. Ito, K. Nishimura, F. Naaim-Bouvet, H. Bellot, X. Ravanat, et al.. Wind and snow particle distribution in powder snow cloud. International Snow Science Workshop (ISSW), Oct 2013, Grenoble - Chamonix Mont-Blanc, France. p. 587 - p. 590. ⟨hal-00948614⟩