Squeaky Snow

  1. AEM

    AEM 362
    Gold Member

    Right now it's a bit chilly in the upper midwest (-21 degrees this morning at 6:00 am; -23 degrees predicted for tonight). When walking our dog this afternoon, my wife and I noticed that the snow underfoot squeaked louder that usual. We observe that snow makes a qualitatively different sound depending on temperature with the most noticeable squeaking starting at about -10 degrees. (All degrees in this post are Farenheit.) Why should the sound made when walking on snow depend on temperature, and why should it appear louder the lower temperature?
     
  2. jcsd
  3. mgb_phys

    mgb_phys 8,952
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    Homework Helper

    Everything you ever wanted to know about snow
    http://nsidc.colorado.edu/snow/faq.html

     
  4. PhanthomJay

    PhanthomJay 6,215
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    I suppose this site offers as good an explanation I can find:
    http://cimss.ssec.wisc.edu/wxwise/squeak.html

    Apparently, at the colder temps, the water in the snow freezes, and thus becomes a dry (i.e, water in its frozen state) snow, causing crushing of the ice crystals , and hence, more noise as you walk on it; also, the sound is not absorbed as well as a fresh fallen snow, so the sound is louder. I've noticed, however, that when the temperature is around 20 to 30 degrees or more, degrees F, the snow is relatively quiet when you walk on it; in the 0 to 20 degree range, degrees F, you get a "crunch,crunch" sound; and when the temperature drops below zero, you get that "squeak, squeak" sound. I'll check it out tomorrow morning when the temperature is expected to drop to 5 below in these parts. Interesting!
     
  5. AEM

    AEM 362
    Gold Member

    Thanks for the feedback and links. My wife (who is an applied mathematician) and I had surmised the answer, but it's nice to have confirmation. Stay warm!
     
  6. Andy Resnick

    Andy Resnick 5,805
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    Education Advisor

    Interesting links. I also know that different ski wax formulations are used for different temperatures- don't know any real details, other than they are different colors.
     
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