Snowmelt acceleration by dust deposition
Artificial dust deposition on snow surfaces is hypothesized to lower the albedo of the snow surface, increase shortwave energy absorption, and accelerate the spring snowmelt cycle. This is a procedure to generate dust similar to naturally deposited dust in the western U.S. and distribute it on a snowpack.
- Prodedure in use at Hidden Canyon(and expected to influence ecohydrology(plant water balance, soil moisture, C cycling) in plots with enhanced dust deposition.
- Regional dust sources
- The snowmelt measurements page for Hidden Canyon.
Dust collection and preparation
- Dust is dug from the ground at an appropriate source site. Care is taken not to dig large amounts of organic matter, seeds, roots, etc.
- Dust dried in drying ovens for at least 24 hours
- Sift to 500µm or less.
Dust is applied to the snow surface in treatment plots during the spring snowmelt season. Dust application begins before peak snowpack (April 15), and dust is reapplied each time new snow covers the prior dust layer until the snowpack has melted completely.
Application amounts (Hidden Canyon experiment)
- Target deposition rate: ~5g per m^2^
- Application area: 10m by ~70m = 700 m^2^
- Probable number of applications: 8
- Total dust needed: 5g x 700 m^2^x 8 = 28000g
- Blower method Dust is blown onto the snowpack using a small ShopVac modified to blow air through a PVC extension. The PVC pipe is fitted with a dust "cartridge" (a mason jar) that feeds dust into the airstream at a steady rate. The blower is powered by a 12V battery and inverter carried in a backpack. Each mason jar holds 1200g of dust. Roughly 3 should cover a 700m^2^plot. This method was used in 2010 at Hidden Canyon.
- Throwing method Dust is scattered tossed by hand onto the snowpack.
- The best days for either method are relatively calm days with little wind.