Item: Surface hoar growing for several days
Title: Surface hoar growing for several days
Proceedings: Proceedings of the 1996 International Snow Science Workshop, Banff, Canada
Authors: Akihiro Hachikubo and Eizi Akitaya, Institute of Low Temperature Science, Hokkaido University, Sapporo 060, Japan, Tel: (81) 11-706-5476, Fax: (81) 11-706-7142, e-mail: email@example.com
Abstract: Surface hoar growing for several clear and humid days were observed. In the daytime, the air and the snow surface temperature increased and the relative humidity decreased, hence evaporation (sublimation) occurred at the snow surface. The amount of evaporation calculated with a bulk method was enough to evaporate out the surface hoar crystals which grew previous night, but they were observed to survive on the snow surface even in the daytime. In the following nights new hoar crystals formed on the old ones and developed largely. This result suggested that the surface hoar crystals were cooled by outgoing radiation even in the daytime and kept their size, while snow grains underneath the surface were warmed by solar radiation and evaporated. The layer composed of the surface hoar and the depth hoar crystals showed a very weak shear strength.
Keywords: surface hoar, weak layer, radiative cooling
Digital Abstract Not Available