Near-Surface Faceted Crystal Growth and Snow Stability in a High-Latitude Maritime Snow Climate

TitleNear-Surface Faceted Crystal Growth and Snow Stability in a High-Latitude Maritime Snow Climate
Publication TypeConference Proceedings
Year of Conference2003
AuthorsScheler, K., Hood E., Carter P., and Glude B.
Conference Name71st Annual Western Snow Conference
Series TitleProceedings of the 71st Annual Western Snow Conference
Date PublishedApril 2003
PublisherWestern Snow Conference
Conference LocationScottsdale, Arizona
KeywordsJuneau, Alaska, avalanche, temperature, vapor pressure, faceted crystal growth

The City and Borough of Juneau, Alaska has several major avalanche paths located in close proximity to population centers and is routinely affected by avalanche activity. However, due to a lack of funding and research, Juneau is largely unprepared for potentially catastrophic avalanche events. This study investigates temperature and vapor pressure gradients associated with near-surface faceted crystal formation in the high-latitude maritime snow climate of southeast Alaska. Here we report on two episodes in March and April 2003 in which temperature gradients measured in the upper 25 cm of the snowpack were in excess of 70?C m-1. During both of these periods, faceted crystals 1-2 mm in diameter were observed to form near the surface of the snowpack. Field tests performed simultaneously at our study site demonstrated pronounced instabilities associated with the newly formed faceted crystals. Furthermore, avalanche activity was observed following both periods. Investigations of proximate avalanches showed that wind-loaded dry slabs were running on layers of near-surface faceted crystals.