Measuring snowpack dust-loading

Many different samples from a snowpack can be returned to the lab. These are generally sampled on an ground-area or snow-volume basis, and the idea with this procedure is to filter out the dust in each sample to return a dust loading for each type of sample. Samples that can be treated this way include:

  • Full or partial snow column samples taken with a coring device (like a PVC sampling tube).
  • Kelly cutter samples - 1L volume samples taken along a snow depth profile.
  • Surface scrapes - known-area surface snow collections.


  1. Thaw sample in a covered, leakproof container
  2. Snow samples are sometimes returned in a ziploc bag, and often these have small holes in them. Therefore they must be thawed in a leakproof container.
  3. There are numerous containers in the lab suitable for defrosting these bags, just be sure they are big enough not to overflow.
  4. It is important to cover the thawing sample with a lid to prevent evaporation (especially when water isotopes are being measured).
  5. Once thawed, empty all contents of the sample bag into its thawing container (make sure it is labeled with a sample ID).
  6. As you do this, be sure to suspend all dust in the sample bag by swishing it around
  7. Tare a 500ml (or larger) beaker on the balance.
  8. Transfer the sample from its thawing container into the tared beaker and record the weight of the sample on the datasheet.
  9. The sample is now ready to filter
  10. Record the weight of a clean, dry glass fiber filter (this can be done in advance) on the datasheet, and then place it in a clean ceramic filter funnel/sidearm flask assembly.
  11. Turn on the vacuum, swish the sample around to suspend the dust, and slowly pour the sample through the filter.
  12. The first portion of the filtrate can be saved for water isotope analysis. If this is done, the filtrate to be saved MUST be filtered into a clean, dry filter flask, then transferred to a plastic sample container. The remaining filtrate does not need to be saved.
  13. After all the sample has been filtered, carefully place the filter on a labeled petri and dry it in the drying oven.
  14. It is important that the 500ml beakers and sidearm flasks are clean and dry when they come in contact with a new sample, so rinse well and let dry between samples. Having a queue of several beakers/flasks will make things proceed faster.
  15. When the filter is dry (24-48hrs), weigh it and record this weight on the datasheet.