Drifting snow in complex terrain. Comparison of measured snow distribution and simulated wind field.

Abstract

Snowdrift in complex terrain can cause significant problems for maintenance of road and railway systems during winter and is a major factor for snow avalanche releases. The location of accumulation and erosion areas is highly connected to the local wind field. The snow distribution in an area of 3 x 4 kilometers is measured by ground penetrating radar. The study area is located at 78° North on Spitsbergen and features elevations from 200 m to 900 m above sea level. Snow distribution measurements are done twice during the field season in winter 1999 to monitor the spatial changes in snow distribution caused by snowstorms. In addition, the wind speed and wind direction is measured at four stations in the study area. The local wind field is simulated using a non-hydrostatic numerical mesoscale model. It can be seen that there is a relationship between snow distribution and wind climate in the area. High wind speeds correspond well to erosion areas while low wind speeds correspond well to accumulation areas. The achieved data can be used in future projects to validate distributed snowdrift models for complex terrain both for risk analysis and hydrological applications.