Upper Kadleroshilik Met Station

Bullen Point Project
Upper Kadleroshilik Met Station (DBM5)
Current Conditions	Historical Data	Station Information	Photo Gallery

Snow Depth Plots

Plot Notes: Distance from sensor to target measured in Sept 2008, baseline value is not zero (shows ~2 cm) during snow-free conditions due to uneven ground surface. Fluctuations in the snow depth may be due to inherent or physical errors as described below.

Site Specific Information:
Average distance from sensor to ground Sept 2008 = 129 cm Ground is vegetated with tussocks up to 30 cm Vegetation trimmed and bark chips added under sensor in Sept 2008 to level the ground surface Average distance from sensor to ground prior to Sept 2008 = 133 cm
Sensor Photographs:
SR50 snow depth sensor on pole before bark chips placed under sensor	Ground surface below SR50 sensor
Ground surface after bark chips placed under sensor	SR50 snow depth sensor on pole after bark chips placed under sensor
SR50 Sensor Description:
The SR50 snow depth sensor has an ultrasonic pulse measurement cone of 22 degrees from the bottom of the sensor to the target. The sensor measures the distance from the sensor to the target (in this case it is the ground surface or snow surface). To calculate snow depth, this distance to target measurement is subtracted from the field measured distance to ground surface. Currently, the sensor records measurements at one minute intervals and reports hourly averages. Potential inherent errors exist; since the speed of sound is affected by the temperature of the air it is traveling in, an air temperature measurement is required to correct the distance reading. Physically related errors include wind and blowing snow creating spurious data readings, difficulty in establishing a zero point due to tussocks, low shrubs, grass, etc., ground heave altering sensor height and angle, as well as cable breakages due to wildlife. Research is underway to improve the measurement with moving averages and weighting schemes.