The Amazing Elasticity of Snow
>> Wednesday, January 20, 2010
It was warm Saturday - several degrees above freezing. The sun was out, and there was virtually no wind. I was so warm snowshoeing that I was happily sweating wearing only old overall leggings that work great for cross country skiing or snowshoing, a super lightweight moisture-wicking shirt, and an unzipped low-tech Barbie-pink fleece that everyone picks on me for. (It IS incredibly bubblegum). Hat and mittens were stuffed in my camera case.
Temperature perception varies dramatically, though, I admit. I snowshoed past one woman swathed to the eyeballs, wearing a calf-length puffy down coat with its hood up over a hat, a huge scarf, mittens, fluffy boots, and insulated pants. She made me hot just to look at, and I'm usually cold!
I don't know if they're any more impartial at judging winter temperatures, but it was warm enough that there were bugs out flying around in a beam of sunlight, which surprised me. I know there are a number of varieties of bugs that like it cold, but I'm not used to seeing anything flying in swarms in the winter. Only a couple showed up in the photo, but there were several dozen of them:
It looks to me like that strip of snow used to lie along the vine, and had slithered around and draped itself off it by the time I came by. It immediately called to mind an incredible snow swath that once graced the railing of the deck at our old townhouse. We'd had a big lake effect snowstorm followed by several days with highs slightly above freezing, and the snow on the railing gracefully slid off the edge and stretched itself downward in an unsupported arc:
Honest - it wasn't formed around a garland or string of Christmas lights or anything - that's 100% snow. Here's another view:
It stayed like that for several days, creeping ever so slowly downward. Eventually it rained, and the snow ribbon was sadly no more. Cool though, huh?
Honestly, everything about snow seems odd to me if I think about it hard enough. The very idea of the landscape being covered in all that stuff seems strange. It's like how a familiar word can suddenly seem spelled wrong if one thinks about it too hard. I may be mighty used to snow, but it still surprises me sometimes.
If I had to guess, I would say the snow bending off branches and railings happens most often when the snowfall has come down as big fluffy flakes rather than granules or graupel. Those pretty flakes with all their little jags and points wind up becoming interlocked as they fall and compress. Then when it gets warm and they start to melt, they still hang together and melt as a mass rather than just as individual flakes, giving the clump of interlocked flakes the ability to droop, fold, hang and stretch. Any snow scientists out there who can confirm my guesswork? Anybody ever quantifiably measured the elasticity of snow? I bet someone has...
4 comments:
I did a post on this very subject a week or two ago (9 Jan) for the Adirondack Almanack (www.adirondackalmanack.com). Your pictures, however, are MUCH better than the one I had! The mechanical strength of snow - amazing stuff. Peter Marchand did a pretty good treatment of this in his book "Life in the Cold."
I was just going to mention Ellen's post on the Almanack from a couple of weeks ago: http://www.adirondackalmanack.com/2010/01/adirondack-weather-strength-of-snow.html
Pretty neat.
Snow is just so cool! I wish we had more of it this winter. I'd better be careful what I wish for, hadn't I? I'm glad the info about Ellen's post was included here. She knows all kinds of good stuff.
Ellen - cool post on the properties of snow! I KNEW there had to be more great info out there. I think I need to find a couple of books on the subject. Fascinating!
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