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Harvard Forest Symposium Abstract 2015

• Title: Snowpack at HFR: IR Sensing of Depth
• Primary Author: Robert Hellstrom (Bridgewater State University)
• Abstract:

  Sub-forest canopy meteorological forcing and snowpack properties can profoundly influence the winter ecology. 3/4 inch graduated PVC snow stakes and web cams were installed at three Harvard Forest (HF) sites including: mixed-hardwood at the Little Prospect Hill (LPH) Eddy Flux Tower, near the Hemlock walk-up tower, and at the open area behind Shaler Hall. Web cameras connected to a laptop at the three sites provided daily images of snowpack surface depth. Snow density profiles were recorded during weekly to monthly site visits from December 2008 to April 2014. Gaps in the datasets were primarily caused by laptop malfunctions and lack of site visits necessary to maintain equipment and to obtain density measurements of the snowpack. There were no site visits to record snowpack properties during the 2011-2012 snow season, a year of unusually low snowfall. This project is ongoing. These datasets would prove useful for research related to snow ecology and hydrology projects at Harvard Forest.
  
  
  
  
  
  The IR sensor was installed in 2011 at the Shaler site. Snow depth was calibrated and validated against two-hourly webcam photographs of a snow depth stake at the site. Preliminary data suggest error due to the dependence on snow surface temperature, although this effect and other minor errors could be removed by applying algorithms based on simultaneous measurements of snowpack temperature and meteorological variables. Figures 1 through 5 illustrate the results, concept and record of snow depth for the 2012-2013 snow season.

• Research Category: Forest-Atmosphere Exchange


• Figures:
Fig1_Snowpack Sites HFR.jpg
Fig2_IR_SnowDepth_2013.jpg
Fig3_Depth_vs_IRsignalvoltage.jpg
Fig4_IR_Proximity_Sensor.jpg
Fig5_SnowDepth_HFR_2013.pdf